A. Cruise Narrative: AR01 A.1. Highlights WHP Cruise Summary Information WOCE section designation AR01 Expedition designation (EXPOCODE) 31RBOACES24N_2 Chief Scientist(s) and their affiliation KITACK LEE* and DAVID S. BITTERMAN** Dates 1998.JAN.23 - 1998.FEB.24 Ship Ronald H. Brown Ports of call Palmas, Canary Islands to Miami, Florida Number of stations 130 27.965° Geographic boundaries of the stations -79.937 E -13.37 24.4913° Floats and drifters deployed none Moorings deployed or recovered none ______________________________________________________________________________ *KITACK LEE, Assistant Professor School of Environmental Science and Engineering ~ Pohang University of Science and Technology San 31, Nam-gu, Hyoja-dong ~ Pohang, 790-784 ~ Republic of Korea TEL: +82-054-279-2285 ~ FAX: +82-054-279-8299 ~ EMAIL: ktl@postech.ac.kr **DAVID S. BITTERMAN Physical Oceanography Division ~ Atlantic Oceanographic and Meteorological Laboratory 4301 Rickenbacker Causeway ~ Miami Florida 44149 ~ United States TEL: (305) 361-4432 ~ EMAIL: David.Bitterman@noaa.gov ABSTRACTED FROM NOAA DATA REPORT 0AR AOML-41 Atlantic Oceanographic and Meteorological Laboratory Miami, Florida June 2001 NOAA: National Oceanic and Atmospheric Administration Ocean and Atmospheric Research Laboratories NOTICE Mention of a commercial company, or product does not constitute an endorsement by NOAA/AOML. Use of information from this publication concerning proprietary products or the tests of such products for publicity or advertising purposes is not authorized. ELECTRONIC ACCESS TO DATA LISTED IN THIS REPORT The data presented in this report is available on the World Wide Web (WWW) at the following sites: Bottle and CTD data: http://www.aoml.noaa.gov/ocd/oaces/24n98.html UWpCO2 data: http://www.aoml.noaa.gov/ocd/oaces/1998data.html ADCP data: http://ilikai.soest.hawaii.edu/sadcp/woce.html LADCP data: http://www.nodc.noaa.gov/General/NODC-About/NODC- overview.html#services For further information regarding the data sets contact: Ms. Betty E. Huss Data Manager, OACES/GCC at: U.S. Dept. of Commerce NOAA/AOML/OCD 4301 Rickenbacker Causeway Miami, Florida 33149-1026 Phone: (305) 361-4395 Email: huss@aoml.noaa.gov LIST OF PARTICIPANTS Leg 1: Function Name Institution Chief Scientist Gregg Thomas AOML pCO2 Dana Greeley PMEL Total Alkalinity Mary Roche UM M-AERI Jennifer Hanafin UM M-AERI Erica Key UM Leg 2: Function Name Institution --------------------------------------------------- Chief Scientist Kitack Lee AOML/CIMAS Co-Chief Scientist David Bitterman AOML CTD Christiane Fleurant AOML/CIMAS CTD/ET Douglas Anderson AOML CTD Kristene McTaggart PMEL Salinity Gregg Thomas AOML Oxygen/ET Robert Roddy AOML Oxygen George Berberian AOML LADCP Ryan Smith AOML/CIMAS LADCP Richard Sikorski UM LADCP Deanna Spindler UM DIC Marilyn Roberts PMEL DIC Esa Peltola AOML/CIMAS pCO2 Dana Greeley PMEL pCO2 Hua Chen AOML CFC David Wisegarver PMEL CFC Fredrick Menzia PMEL Nutrients Calvin Mordy PMEL/JISAO Nutrients Charles Fisher AOML Total Alkalinity Cindy Moore UM Total Alkalinity Xiaorong Zhu UM pH Jason Joliff UM pH Xuewn Liu UM TOC/TN, and TP Rachel Parsons BBSR TOC/TN, and TP Amy Richie BBSR 13C/12C Tania Westby UW The Chief Survey Technician aboard the R/V RONALD BROWN for the cruise was Jonathan Shannahoff. Institutional Abbreviations: Abbr. Institution Address ---------------------------------------------------------------- AOML Atlantic Oceanographic and 4301 Rickenbacker Cwy Meteorological Laboratory Miami, FL 33149-1098 BBSR Bermuda Biological Station St. Georges, GE-01 for Research Bermuda PMEL Pacific Marine Environmental 7600 Sand Point Way NE Laboratory Seattle, WA 98115-0070 UM University of Miami Rosenstiel School of Marine and Atmospheric Science 4600 Rickenbacker Cwy Miami, FL 33149-1098 CIMAS Cooperative Institute for Marine & Atmospheric Studies UW University of Washington Box 357940 Seattle, WA 98195-7940 JISAO Joint Institute for Study of the Atmosphere and Ocean CONTENTS A. Cruise Narrative A.1. Highlights A.2. Cruise Summary A.3. INTRODUCTION. A.4. DESCRIPTION OF STUDY AREA. B. DATA COLLECTION AND ANALYTICAL METHODS. B.1. HYDROGRAPHIC METHODS B.1.1. CTD AND HYDROGRAPHIC OPERATIONS B.1.2. NUTRIENT ANALYSIS METHODS B.2. CARBON PARAMETERS B.2.1. TOTAL DISSOLVED INORGANIC CARBON (DIC) B.2.2. FUGACITY OF CO2 (fCO2). B.2.3. TOTAL ALKALINITY (TA) B.2.4. pH B.2.5. TOTAL ORGANIC CARBON, TOTAL NITROGEN AND TOTAL PHOSPHORUS B.2.6. 13 C/12 C OF DISSOLVED INORGANIC CARBON B.2.7. CHLOROFLUOROCARBONS (CFC) B.3. UNDERWAY MEASUREMENT METHODS. C.3.1. UNDERWAY fCO2. D. ACKNOWLEDGMENTS E. REFERENCES. FIGURES 1. Cruise track for the Atlantic Ocean AR01 cruise in January and February 1998. 2. All parameters measured vs. depth. 3. The results of the CRM measurements 4. The results of the DIC duplicates during the course of the cruise. TABLES 1. Station locations 2. Results of the certified reference material, CRM 3. Dissolved inorganic carbon duplicates 4. Replicate pCO2 analyses 5. Correction factors applied to raw data based upon carbonate parameters for Certified Reference Materials. 6. Replicate dissolved CFC-11 and CFC-12 analyses 7. Replicate dissolved CFC-113 and CCL4 analyses 8. CFC air measurements 9. CFC air values (interpolated to station locations) A.2. Cruise Summary CHEMICAL AND HYDROGRAPHIC MEASUREMENTS ON A CLIMATE AND GLOBAL CHANGE CRUISE ALONG 24° N IN THE ATLANTIC OCEAN WOCE SECTION AR01 DURING JANUARY-FEBRUARY, 1998 E. Peltola, K. Lee, R. Wanninkhof, R. Feely, M. Roberts, D. Greeley, M. Baringer, G. Johnson, J. Bullister, C. Mordy, J.-Z. Zhang, P. Quay, F. Millero, D. Hansell, P. Minnett ABSTRACT This document contains data and metadata from a zonal cruise along nominally 24.5 °N in the Atlantic Ocean from Las Palmas, Canary Islands in Spain to Miami, Florida. The cruise took place from January 23 to February 24, 1998 aboard the NOAA Ship RONALD H. BROWN under auspices of the National Oceanic and Atmospheric Administration (NOAA). This report presents the analytical and quality control procedures performed during the cruise and bottle data from the cruise. The research was sponsored by the NOAA Climate and Global Change Program under: (i) The Ocean- Atmosphere Carbon Exchange Study (OACES); and (ii) the World Ocean Circulation Experiment (WOCE) repeat hydrography program. Samples were taken from up to 36 depths at 130 stations. The data presented in this report includes the analyses of water samples for: salinity, nutrients, total dissolved inorganic carbon dioxide (DIC), fugacity of carbon dioxide (fCO2), total alkalinity (TA), pH, total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), chlorofluorocarbons, and stable carbon isotopic ratio of DIC ( 13 C/ 12 C). Basic hydrographic parameters, pressure, CTD salinity, temperature and the calculated potential temperature, and potential density are included as well. List of Principal Investigators Project Name Institution ----------------------------------------------------------- CTD/O2, LADCP, ADCP, Molly Baringer AOML Salinity, Oxygen CTD/O2 Gregory Johnson PMEL pCO2 Richard Wanninkhof AOML Total CO2 Richard Feely PMEL Chlorofluorocarbons (CFCs) John Bullister PMEL Nutrients Calvin Mordy PMEL/JISAO Nutrients Jia-Zhong Zhang NOAA/CIMAS 13C/12C Paul Quay UW Total Alkalinity, pH Frank Millero UM TOC, TN, and TP Dennis Hansell BBSR M-AERI Peter Minnett UM A.3. INTRODUCTION Since the world's oceans have a large capacity to sequester heat and carbon dioxide it is imperative that the oceans are studied in a comprehensive fashion to elucidate changes in the Earth's climate. An overall goal of the research is to observe and model the ocean sufficiently well to understand quantitatively how the ocean effects present climate, and how the ocean might change under a changing atmosphere. Thus, a long-term objective is to provide reliable predictions of climate change and associated regional implications on time scales ranging from seasons to centuries. Current predictions are uncertain, in part, because of poor understanding of source and sink patterns of greenhouse gases like carbon dioxide and the role of the ocean in mitigating or changing the timing of regional patterns associated with warmer climate. This cruise was designed to support research sponsored by the National Oceanic and Atmospheric Administration (NOAA) Climate and Global Change Program under: (i) the Ocean-Atmosphere Carbon Exchange Study (OACES); and (ii) the World Ocean Circulation Experiment (WOCE) repeat hydrography program. The second leg of the cruise was conducted aboard the NOAA Ship RONALD H. BROWN from January 23 to February 24, 1998. The OACES objective of the cruise was to determine the fluxes of CO2 in the North Atlantic during the winter. A baseline of total carbon inventory in this region was established such that the uptake rate of atmospheric CO2 can be determined in future cruises. The objective of the WOCE (repeat) hydrography component was to understand the general circulation of the global ocean well enough to be able to model its present state and predict its evolution. The data presented in this report includes: hydrography, nutrients, total dissolved inorganic carbon dioxide (DIC), fugacity/partial pressure of carbon dioxide (fCO2/pCO2)* , total alkalinity (TA), pH, total organic carbon (TOC), total nitrogen (TN), total phosphorus (TP), chlorofluorocarbons, and stable carbon isotopic ratio of DIC ( 13 C/ 12 C). Detailed information of the CTD operations can be found in NOAA Data Report, ERL PMEL-68 (McTaggart et al, 1999). * The fCO2 takes into account the non-ideality of CO2 gas and is the thermodynamic quantity mostly used in calculations. It is approximately 0.4 to 0.6 % lower than the corresponding pCO2. In this report we used the terms interchangeably. However, all reported values are fugacity values. A.4. DESCRIPTION OF STUDY AREA A total of 130 full water column CTD stations were occupied, complete with water samples analyzed for salinity, oxygen and chlorofluorocarbon (CFC) content. A large amount of high quality measurements of all the carbonate parameters including underway surface water pCO2 and nutrients were also made. The majority of the data were collected along 24.5 o N from 23.5 o W to 69 o W. Completing the transatlantic section were data collected along a NE-SW dogleg off the coast of Africa, and along a second, short, zonal section along 26.5 o N off the coast of Abaco Island from 69 o W to 77 o W, jogging north along 27 o N in the Straits of Florida to 80 o W. The cruise track and station locations are presented in Figure 1 and Table 1. The leg 1 followed this same trackline in the opposite direction, deploying XBTs to sample the temperature in the upper 750 m, and collecting underway pCO2. B. DATA COLLECTION AND ANALYTICAL METHODS One hundred and thirty CTD (Conductivity-Temperature- Depth) hydrographic stations were occupied to collect discrete water samples and hydrographic data. A CTD/Rosette unit with a Seabird-911 CTD instrument equipped with 36, specially designed 10-L samples bottles was utilized for these casts. These bottles have the same outer dimensions as standard Niskin bottles, but are modified to reduce chlorofluorocarbon sample contamination. Water samples were collected for salinity, oxygen, nutrients, chlorofluorocarbons, 13 C/ 12 C, as well as carbon related parameters including total dissolved inorganic CO2 (DIC), discrete fugacity of CO2 (fCO2), total alkalinity (TA), pH, total organic carbon (TOC), total nitrogen (TN), and total phosphorus (TP) on all casts during the cruise using these modified ioNiskinls style bottles. In the data tables the missing values are assigned a value of -9.0. The WOCE quality control flags have been listed in Appendix A. All the parameters plotted versus depth are shown in Figure 2. Detailed information on individual data collection, and analysis procedures may be found in the following method sections. B.1. HYDROGRAPHIC METHODS B.1.1. CTD AND HYDROGRAPHIC OPERATIONS Description of Measurement Techniques and Calibrations CTD AND IN SITU O2 Depth profiles were obtained with a Seabird 911 plus CTD, deck unit, and rosette pylon. The CTD included dual temperature sensors, dual conductivity sensors, two Beckman oxygen sensors, one Paroscientific pressure transducer, and two pumps to decrease the response time. Thirty-six 10-l "Niskin" bottles were mounted on the frame, along with the CTD, pinger, Lowered Acoustic Doppler Current Profiler (LADCP), and LADCP external battery pack. The bottles were specially designed to reduce chlorofluorocarbon contamination. These bottles have the same outer dimensions as standard 10-l "Niskin" bottles, but use a modified end-cap design to minimize the contact of the water sample with the end-cap O-rings after closing. The O-rings used in these water sample bottles were vacuum-baked prior to the first station. Stainless steel springs covered with a nylon powder coat were substituted for the internal elastic tubing standardly used to close "Niskin" bottles. Seabird software was used to acquire, plot, and process the CTD data on PC's. Raw data were stored on VHS tapes, PC hard drives, and SyQuest drives. Typically each cast sampled to within 10 meters of the sea floor as indicated by the pinger signal. The CTD/O2 data were processed and calibrated following Seabird recommendations (CTD Data Acquisition Software and Technical Notes, Sea- Bird Electronics, Inc., 1808 - 136th Place NE, Bellevue, Washington 98005). Exceptional items are noted below. Details can be found in NOAA Data Report, ERL PMEL-68 (McTaggart et al, 1999, p. 37 in this document). Pre- and post-cruise pressure, temperature, and conductivity sensor calibrations were performed at Sea-Bird Electronics, Inc. in Bellevue, Washington. Secondary sensor pair T1075 and C1347 were selected for final data reduction for all stations. The oxygen sensor was calibrated by using the pre- and post-cruise laboratory calibration. Secondary oxygen data from sensor s/n 353 was retained for stations 1-32 and 34; primary oxygen data from sensor s/n 381 was retained for stations 33 and 35-130. Post-cruise calibrations were applied to CTD data associated with bottle data using the PMEL program CALBOT. WOCE quality flags were appended to bottle data records using the PMEL program FLAG. Quality flags were determined by plotting the absolute value of sample residuals versus pressure and selecting a cutoff value for bad flags. Values which were 2.8 standard deviations from the mean were considered bad. Of the 4313 sample salinities, 0.4% were flagged as bad and 3.6% were flagged as questionable. Of the 4130 sample oxygens, 1.2% were flagged as bad and 4.9% were flagged as questionable. MEASUREMENT OF CURRENTS A hull-mounted RD Instruments 150 kHz narrowband acoustic Doppler current profiler (ADCP) operated continuously during the cruise. Velocity data, averaged in earth coordinates using gyrocompass heading, were logged in three-minute (approximately 180 pings) ensembles using RDI Data Acquisition Software (DAS) version 2.48. Vertical bin size was 8 meters. The center of the first bin was located at 16 meters. Range varied from 200 to 400 meters, depending primarily on sea state. A user exit program (UE4, provided by Eric Firing, U. Hawaii) was used to interface navigation and heading equipment. Position was logged at the beginning and end of each ensemble from a Trimble Centurion P-code GPS receiver (estimated position accuracy of 5 - 10 meters). Mean gyrocompass corrections for each ensemble were recorded from an Ashtech 3DF GPS attitude determination system; 3DF array orientation was calibrated using P- code GPS and ADCP bottom track comparison. These data are used in post- processing to calculate mean ship velocity to reference ensemble means, and to compensate for dynamic gyrocompass errors. Estimated errors for an ensemble are 1-2 cm/s for relative velocity and 3-4 cm/s for ship speed errors due to position inaccuracy; errors induced by heading inaccuracies are reduced to less than 1 cm/s using GPS heading data. This total error of 4-6 cm/s over a three minute ensemble is reduced further by averaging during postprocessing; the fifteen minute averages commonly used represent an average over five kilometers at cruising speed, and should be accurate to 1-3 cm/s. The ADCP data will be available through internet address: http://ilikai.soest.hawaii.edu/sadcp/woce.html On-station velocity profiles were obtained using a RDI 150 kHz Narrowband ADCP (Lowered or LADCP) mounted looking downward from the CTD frame. This technique measures and records velocity shear profiles extending 150 to 350 meters below the instrument approximately once per second. In postprocessing, the individual shear profiles are averaged by depth to produce a full-depth shear profile, which is integrated to estimate the depth dependent (baroclinic) component of the velocity field. The depth- independent (barotropic) component of velocity can be recovered if positions at the start and end of the cast are known; positions were logged on this cruise using a Trimble Centurion P-code GPS receiver, accurate to 5 - 10 meters. Readers are advised to refer to Fischer and Visbeck (1993) for a full explanation of methods and standard processing procedures. The LADCP data will be available through internet address http://www.nodc.noaa.gov/General/NODC-About/NODC- overview.html#services SALINITY ANALYSES A Guildline 8400B autosal was used for the salinity analysis with batch P125 standard water. The autosal room was maintained at 22 °C, and the autosal was set at 24 °C. A total of 4380 samples were measured and 37 of them were rejected. OXYGEN TECHNIQUE An automatic titration system was used for the oxygen analysis with the Carpenter modification of the Winkler method using a photometric determined endpoint. Reagents for the Carpenter method titration were mixed by the AOML/OCD Group of George Berberian as specified in Friederich's MBARI Technical Report #91-6 (Friederich et al, 1991). Apparent oxygen utilization (AOU) is defined as O2 measured- O2 sat., where O2 sat. is the saturation value at potential temperature and salinity of the sample determined according to Weiss (1970). A total of 4310 samples were measured and 52 of them were rejected. B.1.2. NUTRIENT ANALYSIS METHODS SAMPLING AND ANALYTICAL METHODS Nutrient samples were collected from 10-L "Niskin" bottles in acid washed 25-ml linear polyethylene bottles after three complete seawater rinses and analyzed within 1 hour of sample collection. Measurements were made in a temperature- controlled laboratory (20 ± 2 ºC). Concentrations of nitrite (NO2 - ), nitrate (NO3 - ), phosphate (PO4 3- ) and silicic acid (H4SiO4) were determined using an Alpkem Flow Solution Auto-Analyzer aboard the ship. The following analytical methods were employed: NITRATE AND NITRITE: Nitrite was determined by diazotizing with sulfanilamide and coupling with N-1 naphthyl ethylenediamine dihydrochloride to form an azo dye. The color produced is measured at 540 nm (Zhang et al., 1997a). Samples for nitrate analysis were passed through a home made cadmium column (Zhang et al., 2000), which reduced nitrate to nitrite and the resulting nitrite concentration was then determined as described above. Nitrate concentrations were determined from the difference of nitrate + nitrite and nitrite. PHOSPHATE: Phosphate in the samples was determined by reacting with molybdenum (VI) and antimony (III) in an acidic medium to form an antimonyphosphomolybdate complex at room temperature. This complex was subsequently reduced with ascorbic acid to form a blue complex and the absorbance was measured at 710 nm (Grasshoff et al., 1983). A total of 4306 samples were measured and 1248 of them were rejected. SILICIC ACID: Silicic acid in the sample was analyzed by reacting the aliquot with molybdate in a acidic solution to form € -molybdosilicic acid . The € -molybdosilicic acid was then reduced by ascorbic acid to form molybdenum blue (Zhang et al., 1997b). The absorbance of the molybdenum blue was measured at 660 nm. CALIBRATION AND STANDARDS: Stock standard solutions were prepared by dissolving high purity standard materials (KNO3 , NaNO2 , KH2PO4 and Na2SiF6 ) in deionized water. Working standards were freshly made at each station by diluting the stock solutions in low nutrient seawater. The low nutrient seawater used for the preparation of working standards, determination of blank, and wash between samples was filtered seawater obtained from the surface of the Gulf Stream. Standardizations were performed prior to each sample run with working standard solutions. Two or three replicate samples were collected from the "Niskin" bottle sampled at deepest depth at each cast. The relative standard deviation from the results of these replicate samples were used to estimate the overall precision obtained by the sampling and analytical procedures. The precisions of these samples were 0.04 µmol/kg for nitrate, 0.01 µmol/kg for phosphate and 0.1 µmol/kg for silicic acid. B.2. CARBON PARAMETERS B.2.1. TOTAL DISSOLVED INORGANIC CARBON (DIC) The DIC analytical equipment was set up in a seagoing laboratory van. The analysis was done by coulometry with two analytical systems (PMEL-1 and PMEL-2) used simultaneously on the cruise. Each system consisted of a coulometer (UIC, Inc.) coupled with a SOMMA (Single Operator Multiparameter Metabolic Analyzer) inlet system developed by Kenneth Johnson (Johnson et al., 1985,1987,1993; Johnson, 1992) formerly of Brookhaven National Laboratory (BNL). In the coulometric analysis of DIC, all carbonate species are converted to CO2 (gas) by addition of excess hydrogen ion (acid) to the seawater sample, and the evolved CO2 gas is swept into the titration cell of the coulometer with compressed nitrogen, where it reacts quantitatively with a proprietary reagent based on ethanolamine to generate hydrogen ions. These are subsequently titrated with coulometrically generated OH-. CO2 is thus measured by integrating the total charge required to achieve this. The coulometers were calibrated by injecting aliquots of pure CO2 (99.995%) by means of an 8-port valve outfitted with two sample loops that had been calibrated at BNL (Wilke, 1993). The CO2 gas volumes bracketed the amount of CO2 extracted from the water samples for the two PMEL systems. All DIC values were corrected for dilution by 0.2 ml of HgCl2 used for sample preservation. The total water volume was 540 ml. The correction factor used for dilution was 1.00037. The instruments were calibrated at the beginning, middle, and end of each coulometer cell solution with a set of the gas loop injections. The coulometer cell solution was replaced after 25 mg of carbon was titrated, typically after 9-12 hours of continuous use. Sample titration times were 9-16 minutes. Certified Reference Materials (CRMs), consisting of poisoned, filtered, and UV irradiated seawater supplied by Dr. A. Dickson of Scripps Institution of Oceanography (SIO), were run on each cell. The results were close to the values determined manometrically by Dr. Charles D. Keeling at SIO as shown below. The CRM results have been presented in Figure 3 and Table 2. The overall accuracy and precision for the CRMs on both instruments combined was -0.1 +/-2.1 (n=125). DIC data reported for this cruise have been corrected to the Batch 40 CRM value by adding the difference between the certified value and the mean shipboard CRM value (certified value - shipboard analyses) on a per instrument/per leg basis. Av. value of CRMs run on PMEL-1: 1987.3±2.0 µmol/kg (n = 59) Av. value of CRMs run on PMEL-2: 1984.6±1.2 µmol/kg (n = 66) Manometric value was 1985.8±0.7 µmol/kg (n = 10) [SIO reference material batch #40] Samples were drawn from the "Niskin" bottles into cleaned, precombusted 500-ml Pyrex bottles using Tygon tubing according to procedures outlined in the Handbook of Methods for CO2 Analysis (DOE, 1994). Bottles were rinsed once and filled from the bottom, overflowing half a volume. Care was taken not to entrain any bubbles. The tube was pinched off and withdrawn, creating a 5-ml headspace, and 0.2 ml of saturated HgCl2 solution was added as a preservative. The sample bottles were sealed with glass stoppers lightly covered with Apiezon-L grease, and were stored at room temperature for a maximum of 12 hours prior to analysis. Replicate seawater samples were taken from both the surface and 1000 m "Niskin" sample bottles and run at different times during the cell. The first replicate of the surface water was used at the start of the cell with fresh coulometer solution, the second surface water replicate in the middle of the cell after about 12 mg of C were titrated. The first one of the 1000 m replicates was run at the end of the cell after about 25 mg of C were titrated, while the second one of the 1000 replicate samples was run using a new coulometer cell solution. No systematic difference between the replicates was observed. As example, the 1000m replicate samples run on both PMEL1 and PMEL2 combined had a standard deviation of 1.3 µmol/kg for 32 sets of duplicates, and the results of the surface replicates yielded a standard deviation of 0.9 µmol/kg for 98 sets of duplicates. The deviation is very similar to that observed for the CRMs and suggest no strong dependency of results with amount of carbon titrated for a particular cell. The results of the duplicate samples have been presented in Figure 4 and Table 3. CALCULATIONS Calculation of the amount of CO2 injected was according to the Department of Energy (DOE) CO2 handbook [DOE, 1994]. The gas loops yielded a calibration factor for the instrument defined as: calculated moles of CO2 injected from gas loop Cal. f actor = -------------------------------------------------------- (1) actual moles of CO2 injected The concentration of CO2 ([CO2]) in the samples were determined according to: (Counts - Blank * Run Time) * K µmol/count [CO2] = Cal factor *. ------------------------------------------------- (2) pipette volume * density of sample where "Counts" is the instrument reading at the end of the analysis, "Blank" is the counts/minute determined from blank runs performed at least once for each cell of the solution, "Run Time" is the length of coulometric titration (in minutes), and K is the conversion factor from counts to µmol which is dependent on the slope and intercept relation between instrument response and charge. For a unit with Ecal slope of 1 and intercept of 0, the constant is 2.0728 * 10 -4 . The pipette volume was determined by taking aliquots at known temperature of distilled water from the volumes prior to, during, and after the cruise. The weights with the appropriate densities were used to determine the volume of the syringes and pipette. Calculation of pipette volumes, density, and final CO2 concentration were performed according to procedures outlined in the DOE CO2 handbook (DOE, 1994). B.2.2. FUGACITY OF CO2 (fCO2) GAS CHROMATOGRAPHIC (GC) METHOD A total of 1463 discrete fCO2 samples from 130 stations were taken and analyzed on the cruise using an analysis system based on gas chromatography (Neill et al., 1997). Sampling from the "Niskin" bottles occurred immediately after O2 samples were drawn. Samples were drawn into 120 ml Pyrex septum bottles after rinsing the bottles several times. On the final fill water was drawn into the bottom of the bottle and overflowed at least one half volume. A Teflon lined septum was crimp sealed on the bottle ensuring that no headspace was present. Prior to analysis 5-ml water was withdrawn and replaced with a headspace of known CO2 concentration that was expected to closely match that of the water. The remaining water and headspace were equilibrated by rotating the bottles for at least 40 minutes in a constant temperature bath at 20 °C. The fCO2 of the headspace was measured in a flame ionization detector (FID) after quantitative conversion of the CO2 to methane. The analyses were referenced against a series of six gas standards with the following mole fractions: 198.09, 348.16, 977.79, 508.35, 1479.46, 717.4. The standards, which were run after each dozen samples, bracketed most of the concentrations measured in the water column. The precision of the fCO2 measurements was estimated at 0.86% of the signal based on 89 replicate samples (see Table 4). The fCO2 measurements had a data gap mid- cruise because of a catastrophic instrument failure caused by water being injected onto the column and catalyst. Good, full water column, coverage was obtained at the Eastern and Western side of the basin. The surface water measurements showed that the water undersaturated for most of the transect except at the boundaries. The undersaturation reaches its greatest value of -45 to - 50 µatm between 60 and 75 °E. The fCO2 in the deep water showed a strong trend with lower concentrations in the West due to better ventilation of the Western half of the basin. B.2.3. TOTAL ALKALINITY (TA) Seawater samples were drawn from the "Niskin" bottles with a 40-cm length of silicon tubing. One end of the tubing was fit over the petcock of the "Niskin" bottle and the other end was inserted into the bottom of a 500-ml Corning glass- stoppered sample bottle. The sample bottle was rinsed three times with approximately 300 ml of seawater. The sample bottle was slowly filled from the bottom. Once filled, the sample bottles were kept in a constant water bath at 25°C for half-hour before analysis. The titration system used to determine TA consisted of a Metrohm 665 Dosimat titrator and an Orion 720A pH meter controlled by a personal computer (Millero et al., 1993). The acid titrant, in a water-jacketed burette, and the seawater sample, in a water-jacketed cell, were kept at 25±0.1°C with a Neslab constant- temperature bath. The plexiglass water-jacketed cells were similar to those used by Bradshaw et al. (1988), except that a larger volume (200 ml) was used to increase the precision. The cells had fill and drain valves with zero dead- volume to increase the reproducibility of the cell volume. The HCl solutions used throughout the cruise were made, standardized, and stored in 500-ml glass bottles in the laboratory for use at sea. The 0.2489 M HCl solutions (Batch 9601) were prepared by dilution of concentrated HCl in 0.45 M NaCl to yield an ionic strength equivalent to that of average seawater (0.7 M). The acid was independently standardized using a coulometric technique (Taylor and Smith, 1959; Marinenko and Taylor, 1968) by the University of Miami and by Dr. Dickson of Scripps Institution of Oceanography (SIO). The two standardization techniques agreed to +/-0.0001 N. The volume of HCl delivered to the cell is traditionally assumed to have a small uncertainty (Dickson, 1981) and is equated with the digital output of the titrator. Calibrations of the Dosimat burettes with Milli Q water at 25°C indicated that the systems deliver 3.000 ml (the value for a titration of seawater) to a precision of 0.0004 ml. This uncertainty resulted in an error of 0.4 µmol/kg in TA. The titrators were calibrated in the laboratory before the cruise. Certified standard Reference Material (CRM) Batch 40 prepared by Dr. Dickson was used at sea to monitor the performance of the titrators. All TA data have been corrected based on CRM values for each cell and each leg (see Table 5) (Millero et al, 2000). Carbonate parameters of surface waters indicate the occurrence of upwelling near the African coast. The surface carbonate parameters are consistent with those collected during the WOCE (World Ocean Circulation Experiment) 1992 cruise that sampled stations along the same latitude (24 o N). Both studies yield values for normalized TA (TA*35/S) of 2291±6 µmol kg -1 . The values of TA for the deep water are in good agreement (± 3.8 µmol/kg). Crossover comparison with OACES 1993 study also showed good agreement (±3 µmol/kg in TA). The pH is on average 0.004 higher than those made on the 1993 cruise. Kitack Lee from AOML/OCD calculated total alkalinity (TA) from spectroscopic pH (25 o C) and coulometric total dissolved inorganic carbon (DIC) using the carbonic acid dissociation constants of Mehrbach et al. (1973) as refit by Dickson and Millero (1987). A value of 1.2 µmol kg -1 has been subtracted from calculated TA values because calculated values are 1.2 µmol kg -1 higher than measured values. B.2.4. pH Seawater samples were drawn from the "Niskin" bottles with a 20-cm length of silicon tubing. One end of the tubing was fit over the petcock of the "Niskin" bottle and the other end was attached over the opening of a 10-cm glass spectrophotometric cell. The spectrophotometric cell was rinsed three to four times with a total volume of approximately 200 ml of seawater; the Teflon endcaps were also rinsed and then used to seal a sample of seawater in the glass cell. While drawing the sample, care was taken to make sure that no air bubbles were trapped within the cell. The sample cells were kept in a waterbath at 25°C for a half an hour before analysis. Seawater pH was measured using the spectrophotometric procedure (Byrne, 1987) and the indicator calibration of Clayton and Byrne (1993). The indicator was an 8.0-mM solution of Kodak m-cresol purple sodium salt (C21H17O5Na) in MilliQ water. The absorbance ratio of the concentrated indicator solution (RI = 578A/434A) was 0.95. All absorbance ratio measurements were obtained in the thermostatted (25.0±0.05°C) cell compartments of HP 8453 UV-visible Diode Array Spectrophotometers. Measurements of pH were taken at 25°C on the total hydrogen ion concentration ([H+]T) scale, in mol/kg solution, and converted to seawater scale ([H+]sw). The overall precision of the pH measurements obtained from the duplicate samples was ±0.0006. A total of 1997 samples were measured and 24 of them were rejected. B.2.5. TOTAL ORGANIC CARBON, TOTAL NITROGEN AND TOTAL PHOSPHORUS TOTAL ORGANIC CARBON ANALYSES TOC samples were analyzed by a high-temperature combustion (HTC) method using custom made instruments. Samples were analyzed with a furnace divided into two temperature zones (Hansell and Peltzer, 1998; Carlson et al., 1999). Ultra high purity O2 flowed through the instrument at 175 ml/min. Samples were acidified (10 µl of 85% H3PO4 per 10 ml of sample) and sparged with CO2 free oxygen for at least 10 minutes to remove inorganic carbon. One hundred µl of sample was injected manually through a septumless port into the quartz combustion tube packed with Pt gauze (Aldrich), 7% Pt on alumina catalyst (Shimadzu), Sulfix (Wako Pure Chemical Industries, Inc.) and CuO wire (Leeman Labs). The Pt gauze and Pt beads were heated to 800°C in the upper zone while the remaining packing material was heated to 600°C in the lower zone. The resulting CO2 flowed through two water traps and a final copper halide trap then detected with a LiCor 6252 CO2 analyzer. The signal was integrated with chromatographic software (Dynamax Macintegrator I version 1.3; Rainin Inst.). Extensive conditioning of the combustion tube was essential to minimize the machine blank. The system blank (<10 µM) was assessed daily with ampoulated low carbon waters (LCW). The system response was standardized daily with a four point calibration curve of glucose solution in LCW. Deep Sargasso Sea water (>2000 m), which had been acidified and ampoulated, served as a daily reference material. Analyzing low carbon water and reference deep seawater several times a day allowed us to assess the system stability from run-to-run and day-to-day, ensuring confidence in our analysis. Both the low carbon and the deep Sargasso Sea references waters are part of an international certified reference material program for marine DOC measurement, run by the laboratory of Dr. Hansell. As such, the TOC analyses from the 24°N line are referenced to the international community of DOC laboratories using the CRM(tm)s. TOTAL NITROGEN ANALYSES Concentrations of TN (total nitrogen, or the sum or organic and inorganic N) were determined by high temperature combustion and detection of the nitric oxide produced. Samples had been collected into 60 ml polyethylene bottles for frozen storage until analysis in the shore laboratory. In the high temperature system, a €ls quartz combustion tube was held at 900 °C in the upper zone and 800-900 °C in the lower zone of a 2-zone Thermcraft tube furnace. The combustion tube has a 12 cm head space, 2-3 screens of pure Pt (52 mesh), an 8 cm bed of 7% Pt on alumina (Shimadzu, Inc.), and a 10 cm bed of quartz beads. 100 µl injections of seawater were made into the combustion tube by syringe through a septum. The carrier gas (UHP oxygen) flowed at a rate of 200 ml/min. Recovery of known standards (glycine, urea, EDTA, etc.) was >90%. Detection of NO was done with an Antek Model 7020 chemiluminescence detector. Oxygen flow through the ozone generator was 28 ml/min. Standardization was performed daily with potassium nitrate in Milli-Q water. Q water was used as the system blank, and it was assumed to have zero N content. The system blank was normally <1 µM. Low nutrient sea water, collected at the surface of the Sargasso Sea, was used as a reference material for daily use. The coefficient of variation in low nutrient surface water (4-5 µM TN) was 3-4%, while in deep water (>20 µM TN) it was 1%. Data acquisition was performed on a Dynamax Macintegrator I version 1.3, produced by Rainin Instruments. TOTAL PHOSPHORUS ANALYSES Concentrations of TP (total phosphorus; organic plus inorganic P) were determined by UV photo-oxidation. Samples had been stored frozen in 60 ml polyethylene bottles until shore based analysis. A 6 ml aliquot was removed from each sample bottle and placed in a 20 ml fused quartz tube equipped with a Pyrex ground stopper (Quartz Scientific, Inc.). One hundred µl of 30% hydrogen peroxide was added to each tube and placed in a homemade irradiation unit (2 hours). The irradiation unit contained a 1200 W UV lamp (Hanovia) protected by a quartz jacket. A 2-tiered aluminum tube holder (40 tubes total) fitted around the lamp and held the samples 7 cm from the lamp. A fan placed at the bottom of the unit blew air across the samples for cooling. A hinged aluminum cylinder, open at the top and bottom, was fitted around the samples to keep stray UV light from leaving the system. This entire unit was placed in a fume hood, the front of which was covered with a black curtain while in use (again to collect stray UV light). After irradiation, aliquots of the samples that had not been oxidized, and the photo- oxidized aliquots, were analyzed for phosphate using a colorimetric method on a Technicon Autoanalyzer II (Knap et al. 1997). Daily calibration was achieved from 4 point calibration curves using KH2PO4. Low nutrient seawater (Sargasso Sea surface water) was always processed with the samples as a daily quality control measure. Coefficients of variation for the measurement was X and X% for shallow and deep water samples. B.2.6. 13C/12C OF DISSOLVED INORGANIC CARBON SHIPBOARD SAMPLE COLLECTION METHODS Samples were collected in pre-washed and baked (450 ºC) 500 ml ground glass- stoppered bottles using the following method. A length of Tygon tubing was attached to the "Niskin" bottle or seawater line and flushed for a few seconds. The end of the tubing was then placed at the bottom of the upright sample bottle and the bottle was filled, then overflowed with an amount equal to its volume if "Niskin" water volume permitted, otherwise with at least half its volume. Flow was stopped as the Tygon tubing was removed from the top of the bottle to avoid any splashing in the top. Using a syringe or turkey baster, 10 to 20 ml were withdrawn off the top of the sample to lower the water level to approximately 1 ml below the neck of the bottle, avoiding backwash of water from the turkey baster into the sample. The ground glass joint of the bottle was wiped dry with Kimwipes. Then 100 µl of a saturated HgCl2 solution (per 250 ml of seawater) was injected beneath the surface of the sample using an Eppendorf pipet. The ground- glass stopper, which had been pre-greased with Apiezon M grease, was then inserted straight into the bottle without twisting. If any air streaks in the grease seal were visible, the stopper was removed, cleaned, and regreased, and the bottle was resealed. Clips (if required for the bottle neck-type) were placed on the necks of the bottles, and two heavy rubber bands were placed around the stopper and bottle to prevent leakage. The sample bottle was then inverted a couple of times to mix the HgCl2 throughout the sample. LABORATORY METHODS CO2 is extracted from the DIC seawater sample using a modification of the helium stripping technique described by Kroopnick (1974) as described in Quay et al (1992). The stripper is comprised of a glass tube with a stainless steel fitting and silicone-greased glass stopcock at the bottom (which connects to the He line), a glass frit which the He passes through, and a stainless steel fitting containing a 3-layer silicone rubber septum at the top. Approximately 1 ml phosphoric acid is injected into the stripper and bubbled with He for 10 minutes. The gas is then evacuated out of the stripper and the stripper is weighed. Then 80 to 125 ml of the sample is drawn into the stripper and it is weighed again to calculate the weight of water analyzed. A stainless steel needle pierces the septum and connects the stripper to the extraction line, which has been evacuated and filled with helium. The sample is stripped with 99.997% pure He at a flow rate of 200 ml/min for 20 minutes. Water is trapped out in two glass traps submerged in Dewars containing a slush mixture of dry ice and isopropanol at -70ºC. CO2 is collected at -196ºC in glass loop traps submerged in liquid N2. The € 13 C is then measured on a Finnigan MAT 251 mass spectrometer. The efficiency of the extraction method is 100 ± 0.5 percent based on gravimetrically prepared Na2CO3 standards. The precision of the 13 C/ 12 C analysis is ± 0.02 0 /00 based on a replicate analysis of standards and seawater samples. B.2.7. CHLOROFLUOROCARBONS (CFC) As described above specially designed 10-l water sample bottles were used on the cruise to reduce CFC contamination. Samples for the analysis of dissolved CFC-11, CFC-12 and CFC-113 were drawn from approximately 1700 of the 4300 water samples collected during the expedition. Samples for carbon tetrachloride (CCL4 or CFC-10) analysis were drawn from approximately 430 samples. When taken, water samples for CFC analysis were usually the first samples drawn from the 10-l bottles. Care was taken to co- ordinate the sampling of CFCs with other samples to minimize the time between the initial opening of each bottle and the completion of sample drawing. In most cases, dissolved oxygen, fCO2, total CO2, alkalinity and pH samples were collected within several minutes of the initial opening of each bottle. To minimize contact with air, the CFC samples were drawn directly through the stopcocks of the 10-l bottles into 100-ml precision glass syringes equipped with 2- way metal stopcocks. The syringes were immersed in a holding tank of clean surface seawater until analyzed. To reduce the possibility of contamination from high levels of CFCs frequently present in the air inside research vessels, the CFC extraction/analysis system and syringe holding tank were housed in a modified 20' laboratory van on the aft deck of the ship. For air sampling, a 100 meter length of 3/8" OD Dekaron tubing was run from the CFC lab van to the bow of the ship. A flow of air was drawn through this line into the CFC van using an Air Cadet pump. The air was compressed in the pump, with the downstream pressure held at 1.5 atm using a back-pressure regulator. A tee allowed a flow (100 cc min -1 ) of the compressed air to be directed to the gas sample valves, while the bulk flow of the air (>7 l min -1 ) was vented through the back pressure regulator. Air samples were only analyzed when the relative wind direction was within 60 degrees of the bow of the ship to reduce the possibility of shipboard contamination. The Air Cadet pump was run for at least 60 minutes prior to analyzing each batch of air samples to insure that the air inlet lines and pump were thoroughly flushed Concentrations of CFC-11, CFC- 12 and CFC-113 in air samples, seawater and gas standards on the cruise were measured by shipboard electron capture gas chromatography (EC-GC), using techniques similar to those described by Bullister and Weiss (1988). For seawater analyses, a 30-ml aliquot of seawater from the glass syringe was transferred into the glass sparging chamber. The dissolved CFCs in the seawater sample were extracted by passing a supply of CFC-free purge gas through the sparging chamber for a period of 4 minutes at 70 cc min -1 . Water vapor was removed from the purge gas during passage through an 18 cm long x 3/8 inch diameter glass tube packed with the desiccant magnesium perchlorate. The sample gases were concentrated on a cold-trap consisting of a 1/8 inch OD stainless steel tube with an about 7 cm section packed tightly with Porapak N (60-80 mesh). To cool the trap, isopropanol cooled by a Neslab Cryocool refrigeration system was forced from a reservoir beneath the trap to a level above the packing with a stream of compressed nitrogen. After quickly bringing the isopropanol to the top of the trap, a low flow of nitrogen was bubbled through the bath to reduce gradients and maintained a temperature of -20 o C. After 4 minutes of purging the seawater sample, the sparging chamber was closed and the trap was held open for an additional 1 minute to allow nitrous oxide (N20) to pass through the trap and thereby minimize its interference with CFC-12. The trap was isolated, the cold isopropanol in the bath was drained, and the trap was heated electrically to 125 o C. The sample gases held in the trap were then injected onto a precolumn (30 cm of 1/8 inch O.D. stainless steel tubing packed with 80- 100 mesh Porasil C, held at 90 o C), for the initial separation of the CFCs and other rapidly eluting gases from the more slowly eluting compounds. The CFCs then passed into the main analytical column (about 183 cm of 1/8 inch OD stainless steel tubing packed with Carbograph 1AC, 80-100 mesh, held at 90 o C) for final separation, and into the EC detector for quantification. The analysis of carbon tetrachloride was made on a separate, but nearly identical apparatus to the electron capture-gas chromatography system used in the analysis of CFC- 11, CFC-12 and CFC-113 (Bullister and Weiss, 1988). Samples were drawn in the same type of syringes used for the CFC analysis. In the CCL4 system, the sample injection port was flushed with 30-40 ml of sample before injecting sample into a calibrated loop (about 30 ml). After filling, an additional 30 ml of water was pushed through the loop and allowed to overflow. For analysis, a valve was switched and the water sample held in the loop was pushed into the stripper with the same CCL4 free nitrogen that was used to strip the sample. The gases removed from the sample were dried while passing through an ~18 cm x 3/8 inch OD tube of magnesium perchlorate and concentrated on a trap packed with four inches of Porapak N and held at -30 °C during trapping. At the conclusion of stripping, the trap was heated electrically and the contents swept onto the precolumn (0.53mm I. D. x 30 meters, DB624 capillary column, 45 °C)) with clean nitrogen. The desired gases passed on to the main analytical column (0.53mm I. D. x 30 meters, DB624 capillary column, 45 °C), before the precolumn vented the later peaks. All other aspects of the analysis were the same as the CFC analysis. Both of the analytical systems were calibrated frequently using a standard gas of known CFC composition. Gas sample loops of known volume were thoroughly flushed with standard gas and injected into the system. The temperature and pressure was recorded so that the amount of gas injected could be calculated. The procedures used to transfer the standard gas to the trap, precolumn, main chromatographic column and EC detector were similar to those used for analyzing water samples. Two sizes of gas sample loops were present in the CFC analytical system, while four calibrated sample loops were used in the CCL4 system. Multiple injections of these loop volumes could be made to allow the system to be calibrated over a relatively wide range of concentrations. Air samples and system blanks (injections of loops of CFC-free gas) were injected and analyzed in a similar manner. The typical analysis time for a seawater, air, standard or blank sample was 12 minutes on the CFC system and 20 minutes on the CCL4 system. Concentrations of the CFC's and CCL4 in air, seawater samples and gas standards are reported relative to the SIO93 calibration scale (Cunnold, et. al., 1994). Concentrations in air and standard gas are reported in units of mole fraction CFC in dry gas, and are typically in the parts-per-trillion (ppt) range. Dissolved CFC and CCL4 concentrations are given in units of picomoles per kg seawater (pmol kg -1 ). CFC and CCL4 concentrations in air and seawater samples were determined by fitting their chromatographic peak areas to multi-point calibration curves, generated by injecting multiple sample loops of gas from a working standard (PMEL cylinder 33790 for CFC-11, CFC-12 and CFC-113; PMEL cylinder 33780 for CCL4) into the analytical instrument. The concentrations of CFC-11 and CFC-12 in this working standard were calibrated before and after the cruise versus a primary standard (36743) (Bullister, 1984). No measurable drift in the concentrations of CFC-11 and CFC-12 in the working standard could be detected during this interval. Full range calibration curves were run at intervals of 3 days during the cruise. Single injections of a fixed volume of standard gas at one atmosphere were run much more18 frequently (at intervals of 1 to 2 hours) to monitor short term changes in detector sensitivity. Extremely low (<0.01 pmol kg -1 ) CFC concentrations were measured in deep water (>3000 meters) in the Eastern Basin of the North Atlantic between 25 ºW and 45 ºW along this section. Based on the median of CFC concentration measurements in the deep water of this region, which is believed to be nearly CFC-free, blank corrections of 0.003 to 0.015 pmol kg -1 for CFC-11, 0.006 to 0.007 pmol kg -1 for CFC-12 and 0.006 to 0.011 pmol kg -1 for CFC-113 have been applied to the data set. If the measured CFC concentration for a sample is very low, subtracting a blank can result in a very small negative number reported (see Figure 2). No blank corrections were required for the CCL4 data. On this expedition, we estimate precision (1 standard deviation) of 1% or 0.005 pmol kg -1 (whichever is greater) for dissolved CFC-11, 2% or 0.005 pmol kg -1 (whichever is greater) for dissolved CFC-12 measurements (see listing of replicate samples given in Table 6), 4.4% or 0.002 pmol kg -1 for CFC-113 and 1.4% or 0.006 pmol kg -1 for CCL4 (Table 7). The results of the CFC air measurements are reported in Tables 8 and 9. A number of water samples had clearly anomalous concentrations relative to adjacent samples for one or more of the trace gases. These anomalous samples appeared to occur more or less randomly during the cruise, and were not clearly associated with other features in the water column (e.g. elevated oxygen concentrations, salinity or temperature features, etc.). This suggests that the high values were due to individual, isolated low- level CFC contamination events. Measured concentrations for these samples are included in this report, but are given a quality flag of either 3 (questionable measurement) or 4 (bad measurement). A total of 4 analyses of CFC-11, 8 analyses of CFC-12, 3 analyses of CFC-113 and 2 analyses of CCL4 were assigned a flag of 3. A total of 9 analyses of CFC- 11, 8 analyses of CFC-12, 18 analyses of CFC-113 and 4 analyses of CCL4 were assigned a value of 4. B.3. UNDERWAY MEASUREMENT METHODS B.3.1. UNDERWAY fCO2 Underway pCO 2 system version 2.5 (analogous to those described in Ho et al. 1997, and Feely et al. 1998) was used to determine the pCO 2 of surface water and overlaying air on a continuous basis (Keeling 1965, Wanninkhof and Thoning 1993). When in operation, seawater is drawn from the uncontaminated seawater intake from the bow intake approximately 6 meters below the water line to a 30-l shower head equilibrator located in the main laboratory, where the headspace and seawater reach equilibrium on a short time scale. At specific times during an hourly cycle, the content of the headspace is measured by an infrared CO 2 analyzer. Uncontaminated air from the marine boundary layer is drawn continuously from the bow mast to the underway pCO 2 system. At a designated time, air is analyzed by a the infrared CO 2 analyzer, otherwise the air is bled off through a vent . The CO 2 measurements are made by a Li-Cor differential, non-dispersive, infrared (NDIR) CO 2 analyzer (model 6251), and the result is based on the difference in absorption of infrared (IR) radiation passing through two gas cells. The reference cell is continuously flushed with a gas of known CO 2 concentration using the lowest concentration of three reference gas standards. During the hourly cycle the sample cell is flushed with one of three reference gas standards, marine boundary layer air, or headspace gas from the equilibrator. The data may also be downloaded via WWW site:@ http://www.aoml.noaa.gov/ocd/oaces/1998data.html 3. 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International Journal of Environmental Analytical Chemistry, 76(2):99-113. Zhang, J-Z., Ortner P. B., and Fischer, C., 1997a. Determination of nitrite and nitrate in estuarine and coastal waters by gas segmented continuous flow colorimetric analysis. EPA's manual " Methods for the determination of Chemical Substances in Marine and Estuarine Environmental Matrices - 2 nd Edition". EPA/600/R- 97/072. Zhang, J-Z., and Berberian, G. A., 1997b. Determination of dissolved silicate in estuarine and coastal waters by gas segmented continuous flow colorimetric analysis. EPA's manual " Methods for the determination of Chemical Substances in Marine and Estuarine Environmental Matrices - 2 nd Edition". EPA/600/R- 97/072. TABLE 1. Station locations Lat Long | Lat Long STN Cast (°N) (°W) Date | STN Cast (°N) (°W) Date --- ---- ------ ------ --------- | --- ---- ------ ------ --------- 1 1 27.917 13.370 1/24/1998 | 66 1 24.501 52.637 2/9/1998 2 1 27.965 13.404 1/24/1998 | 67 1 24.499 53.183 2/9/1998 3 1 27.883 13.417 1/24/1998 | 68 1 24.500 53.733 2/9/1998 4 1 27.849 13.417 1/24/1998 | 69 1 24.499 54.467 2/10/1998 5 1 27.799 13.816 1/24/1998 | 70 1 24.499 55.201 2/10/1998 6 1 27.617 14.235 1/24/1997 | 71 1 24.500 55.933 2/10/1998 7 1 27.433 14.851 1/24/1998 | 72 1 24.500 56.667 2/11/1998 8 1 27.232 15.596 1/25/1998 | 73 1 24.500 57.400 2/11/1998 9 1 27.032 16.115 1/25/1998 | 74 1 24.500 58.134 2/11/1998 10 1 26.833 16.668 1/25/1998 | 75 1 24.500 58.867 2/12/1998 11 1 26.667 17.199 1/25/1998 | 76 1 24.500 59.600 2/12/1998 12 1 26.517 17.867 1/25/1998 | 77 1 24.500 60.332 2/12/1998 13 1 26.498 18.335 1/26/1998 | 78 1 24.500 60.067 2/12/1998 14 1 26.167 18.817 1/26/1998 | 79 1 24.500 61.801 2/13/1998 15 1 25.983 19.365 1/26/1998 | 80 1 24.500 63.534 2/13/1998 16 1 25.800 19.899 1/26/1998 | 81 1 24.499 63.264 2/13/1998 17 1 25.617 20.433 1/26/1998 | 82 1 24.500 64.000 2/14/1998 18 1 25.424 20.949 1/27/1998 | 83 1 24.500 64.667 2/14/1998 19 1 25.250 21.484 1/27/1998 | 84 1 24.501 65.469 2/14/1998 20 1 25.057 22.032 1/27/1998 | 85 1 24.500 65.200 2/15/1998 21 1 24.783 22.800 1/28/1998 | 86 1 24.500 66.933 2/15/1998 22 1 24.500 23.484 1/28/1998 | 87 1 24.500 67.667 2/15/1998 23 1 24.499 24.216 1/28/1998 | 88 1 24.500 68.401 2/15/1998 24 1 24.500 24.950 1/28/1998 | 89 1 24.500 69.133 2/16/1998 25 1 24.500 25.683 1/28/1997 | 90 1 25.016 69.502 2/16/1998 26 1 24.500 26.416 1/29/1998 | 91 1 25.383 69.867 2/16/1998 27 1 24.499 27.150 1/29/1998 | 92 1 25.759 70.235 2/17/1998 28 1 24.500 27.883 1/29/1998 | 93 1 26.141 70.615 2/17/1998 29 1 24.499 28.617 1/30/1998 | 94 1 26.501 71.012 2/17/1998 30 1 24.499 29.433 1/30/1998 | 95 1 26.500 71.351 2/17/1998 31 1 24.500 30.267 1/30/1998 | 96 1 26.500 71.734 2/18/1998 32 1 24.500 31.084 1/31/1998 | 97 1 26.501 72.100 2/18/1998 33 1 24.500 31.916 1/31/1998 | 98 1 26.501 72.467 2/18/1998 34 1 24.500 32.733 1/31/1998 | 99 1 26.500 72.850 2/18/1998 35 1 24.498 33.567 2/1/1998 | 100 1 26.500 73.217 2/18/1998 36 1 24.502 34.383 2/1/1998 | 101 1 26.500 73.583 2/19/1998 37 1 24.500 35.217 2/1/1998 | 102 1 26.500 73.967 2/19/1998 38 1 24.500 36.033 2/2/1998 | 103 1 26.500 74.251 2/19/1998 39 1 24.500 36.867 2/2/1998 | 104 1 26.500 74.517 2/19/1998 40 1 24.500 37.683 2/2/1998 | 105 1 26.500 74.800 2/19/1998 41 1 24.500 38.513 2/2/1998 | 106 1 26.500 75.084 2/20/1998 42 1 24.500 39.250 2/3/1998 | 107 1 26.500 75.300 2/20/1998 43 1 24.500 39.983 2/3/1998 | 108 1 26.500 75.500 2/20/1998 44 1 24.500 40.533 2/3/1998 | 109 1 26.500 75.701 2/20/1998 45 1 24.500 41.083 2/4/1998 | 110 1 26.500 75.900 2/20/1998 46 1 24.500 41.633 2/4/1998 | 111 1 26.500 76.083 2/20/1998 47 1 24.500 42.183 2/4/1998 | 112 1 26.500 76.200 2/21/1998 48 1 24.500 42.733 2/4/1998 | 113 1 26.483 76.300 2/21/1998 49 1 24.500 43.284 2/4/1998 | 114 1 26.505 76.422 2/21/1998 50 1 24.500 43.473 2/5/1998 | 115 1 26.500 76.517 2/21/1998 51 1 24.500 44.386 2/5/1998 | 116 1 26.500 76.617 2/21/1998 52 1 24.500 44.934 2/5/1998 | 117 1 26.500 76.683 2/22/1998 53 1 24.500 45.484 2/5/1998 | 118 1 26.499 76.753 2/22/1998 54 1 24.500 46.034 2/5/1998 | 119 1 26.500 76.784 2/22/1998 55 1 24.500 46.584 2/6/1998 | 120 1 26.500 76.816 2/22/1998 56 1 24.500 47.134 2/6/1998 | 121 1 26.520 76.901 2/22/1998 57 1 24.501 47.684 2/6/1998 | 122 1 27.001 79.200 2/23/1998 58 1 24.500 48.234 2/6/1998 | 123 1 27.002 79.283 2/23/1998 59 1 24.500 48.782 2/7/1998 | 124 1 27.001 79.381 2/23/1998 60 1 24.500 49.333 2/7/1998 | 125 1 27.038 79.481 2/23/1998 61 1 24.491 49.883 2/7/1998 | 126 1 27.013 79.605 2/23/1998 62 1 24.501 50.433 2/8/1998 | 127 1 27.020 79.674 2/23/1998 63 1 24.501 50.984 2/8/1998 | 128 1 27.002 79.788 2/23/1998 64 1 24.501 51.533 2/8/1998 | 129 1 27.006 79.857 2/23/1998 65 1 24.500 51.149 2/9/1998 | 130 1 26.999 79.937 2/23/1998 TABLE 2. Results of the certified reference material, CRM (Assigned value by SIO 40 = (1985.8 ± 0.7) mmol/kg) Coulometer: PMEL-1 Date GMT Year DIC | Date GMT Year DIC (h:min) Day (mmol/kg)| (h:min) Day (mmol/kg) --------- ------- ---- ---------| --------- ------- ---- --------- 24-Jan-98 16:02 24 1987.0 | 24-Jan-98 15:19 24 1985.3 25-Jan-98 0:41 25 1981.2 | 25-Jan-98 1:02 25 1985.7 25-Jan-98 4:47 25 1987.0 | 25-Jan-98 12:58 25 1986.7 25-Jan-98 15:19 25 1986.7 | 25-Jan-98 23:54 25 1986.6 26-Jan-98 4:29 26 1987.9 | 26-Jan-98 11:18 26 1985.9 26-Jan-98 18:48 26 1987.3 | 26-Jan-98 22:56 26 1985.0 27-Jan-98 7:36 27 1987.1 | 27-Jan-98 11:22 27 1986.6 27-Jan-98 21:31 27 1987.9 | 27-Jan-98 23:46 27 1984.7 28-Jan-98 9:37 28 1985.9 | 28-Jan-98 12:28 28 1985.7 28-Jan-98 22:19 28 1985.6 | 28-Jan-98 21:53 28 1984.8 29-Jan-98 9:02 29 1988.1 | 29-Jan-98 8:57 29 1984.2 29-Jan-98 23:31 29 1986.4 | 29-Jan-98 23:35 29 1985.1 30-Jan-98 22:36 30 1986.6 | 30-Jan-98 12:19 30 1985.4 31-Jan-98 22:11 31 1985.8 | 30-Jan-98 23:14 30 1983.8 1-Feb-98 9:06 32 1985.1 | 31-Jan-98 11:51 31 1983.9 2-Feb-98 6:16 33 1986.2 | 1-Feb-98 4:27 32 1984.1 2-Feb-98 21:23 33 1985.5 | 1-Feb-98 18:18 32 1984.7 3-Feb-98 11:32 34 1988.3 | 2-Feb-98 8:21 33 1985.5 4-Feb-98 4:54 35 1985.8 | 3-Feb-98 1:09 3 4 1 985.5 4-Feb-98 19:43 35 1988.0 | 3-Feb-98 13:40 34 1985.4 5-Feb-98 7:07 36 1988.3 | 4-Feb-98 0:49 35 1984.5 5-Feb-98 21:35 36 1986.7 | 4-Feb-98 13:06 35 1983.7 6-Feb-98 8:47 37 1985.4 | 4-Feb-98 23:48 35 1984.6 6-Feb-98 21:16 37 1986.3 | 5-Feb-98 13:50 36 1984.1 7-Feb-98 7:48 38 1986.5 | 6-Feb-98 2:55 37 1984.2 7-Feb-98 18:14 38 1988.1 | 6-Feb-98 16:49 37 1986.2 8-Feb-98 5:50 39 1987.9 | 7-Feb-98 2:25 38 1983.6 8-Feb-98 17:42 39 1990.8 | 7-Feb-98 9:08 38 1983.6 8-Feb-98 18:36 39 1991.2 | 7-Feb-98 17:03 38 1984.2 9-Feb-98 4:39 40 1983.6 | 8-Feb-98 3:00 39 1983.5 9-Feb-98 17:46 40 1988.6 | 8-Feb-98 12:46 39 1987.5 10-Feb-98 6:53 41 1985.9 | 9-Feb-98 4:50 40 1983.7 10-Feb-98 22:02 41 1986.2 | 9-Feb-98 15:56 40 1985.3 11-Feb-98 13:17 42 1984.9 | 10-Feb-98 7:15 41 1987.2 12-Feb-98 4:52 43 1985.8 | 10-Feb-98 19:42 41 1984.3 12-Feb-98 19:40 43 1985.1 | 11-Feb-98 13:58 42 1983.8 13-Feb-98 9:40 44 1985.3 | 12-Feb-98 0:04 43 1983.8 14-Feb-98 9:27 45 1994.2 | 12-Feb-98 19:06 43 1983.6 14-Feb-98 10:25 45 1992.0 | 13-Feb-98 4:42 44 1984.4 14-Feb-98 19:54 45 1988.4 | 13-Feb-98 16:36 44 1984.8 15-Feb-98 4:46 46 1987.5 | 14-Feb-98 4:10 45 1983.7 15-Feb-98 19:09 46 1986.8 | 14-Feb-98 13:23 45 1984.0 16-Feb-98 17:09 47 1987.7 | 15-Feb-98 3:48 46 1984.6 17-Feb-98 3:02 48 1988.4 | 15-Feb-98 14:02 46 1981.7 17-Feb-98 12:21 48 1988.9 | 15-Feb-98 14:42 46 1982.8 18-Feb-98 4:13 49 1987.5 | 16-Feb-98 0:12 47 1983.7 18-Feb-98 18:30 49 1988.3 | 16-Feb-98 20:14 47 1984.1 19-Feb-98 5:36 50 1989.1 | 17-Feb-98 7:55 48 1984.2 19-Feb-98 14:48 50 1988.3 | 17-Feb-98 18:25 48 1982.8 20-Feb-98 5:01 51 1987.7 | 18-Feb-98 2:52 49 1984.4 20-Feb-98 13:07 51 1988.3 | 18-Feb-98 15:04 49 1983.8 21-Feb-98 0:18 52 1987.0 | 19-Feb-98 2:04 50 1983.0 21-Feb-98 13:12 52 1988.1 | 19-Feb-98 13:42 50 1985.3 22-Feb-98 2:59 53 1988.4 | 19-Feb-98 21:50 50 1983.8 22-Feb-98 16:47 53 1987.7 | 20-Feb-98 8:11 51 1984.3 23-Feb-98 3:41 54 1987.4 | 20-Feb-98 20:36 51 1983.8 23-Feb-98 10:54 54 1986.1 | 21-Feb-98 8:47 52 1986.8 22-Jan-98 15:02 22 1984.2 | 21-Feb-98 18:37 52 1984.5 22-Jan-98 15:16 22 1983.1 | 22-Feb-98 4:37 53 1984.1 24-Jan-98 1:39 24 1986.2 | 22-Feb-98 16:08 53 1984.0 24-Jan-98 6:19 24 1986.5 | 23-Feb-98 4:18 54 1985.9 TABLE 3. Dissolved inorganic carbon duplicates STA BTL Pres DIC Stdev | STA BTL Pres DIC Stdev NO NO (db) µmol/kg | NO NO (db) µmol/kg --- --- ---- ------- ----- | --- --- ---- ------- ----- 1 9 2 2119.7 0.26 | 67 36 5 2050.1 1.62 3 20 2 2103.9 0.33 | 68 36 4 2056.2 0.03 4 22 4 2100.8 0.47 | 69 36 4 2060.2 0.25 5 7 995 2209.6 1.75 | 70 18 1000 2195.2 0.91 5 27 3 2105.0 0.47 | 70 36 5 2056.3 1.32 6 30 3 2096.4 0.12 | 71 36 6 2046.5 0.43 7 31 3 2096.4 0.95 | 72 36 4 2046.1 0.08 9 32 4 2097.8 1.27 | 73 17 1000 2195.1 0.01 11 16 1001 2205.0 0.23 | 73 36 4 2044.4 0.23 12 36 4 2098.4 0.95 | 74 36 7 2033.7 1.69 13 17 1001 2212.5 0.69 | 75 36 5 2041.7 0.27 13 35 4 2099.4 1.70 | 76 36 6 2038.2 0.99 14 32 3 2100.1 0.98 | 77 36 5 2037.6 1.61 15 17 1000 2209.1 0.82 | 78 36 7 2035.3 0.39 15 36 4 2086.9 0.81 | 79 36 5 2035.2 0.38 18 36 4 2100.1 1.52 | 80 36 6 2023.7 0.07 19 18 1000 2212.8 0.44 | 81 36 4 2016.1 0.76 19 36 5 2101.0 0.41 | 82 36 4 2036.6 0.48 20 36 6 2099.1 0.06 | 83 36 4 2041.5 0.26 21 19 1000 2207.9 0.16 | 84 36 6 2036.9 1.46 21 36 6 2098.6 0.08 | 85 36 4 2017.7 0.16 22 36 4 2096.7 0.45 | 86 17 999 2202.1 0.01 23 36 5 2098.3 1.67 | 86 36 4 2018.4 0.79 24 36 3 2096.2 0.18 | 87 36 5 2028.5 0.73 25 36 4 2099.6 1.14 | 88 36 5 2032.7 0.72 26 36 6 2098.6 0.98 | 89 17 1001 2179.8 1.17 30 18 1000 2200.1 1.39 | 90 16 1001 2186.1 0.71 31 18 1000 2200.6 1.88 | 90 36 4 2037.9 0.34 32 36 6 2101.8 0.42 | 94 36 4 2034.8 0.33 36 36 5 2094.6 0.13 | 95 36 4 2035.4 0.54 37 20 1002 2200.4 0.40 | 98 36 4 2043.1 0.89 38 36 4 2090.6 0.35 | 99 36 5 2042.8 0.93 40 36 4 2087.9 0.84 | 101 18 1001 2191.6 1.88 41 19 999 2200.8 0.45 | 101 36 4 2042.2 0.96 41 36 6 2085.0 0.76 | 102 18 999 2187.3 0.54 42 36 3 2076.3 0.84 | 102 36 5 2047.7 0.18 43 17 1000 2195.0 1.90 | 106 36 4 2041.5 0.79 43 36 4 2080.1 0.86 | 107 36 4 2041.6 0.11 46 36 4 2081.0 0.83 | 110 36 4 2037.3 0.85 49 20 997 2194.9 1.15 | 111 36 4 2039.0 0.06 50 36 5 2077.0 0.01 | 112 18 999 2190.4 1.20 51 19 1001 2193.5 0.78 | 113 36 3 2040.1 1.11 51 36 5 2073.1 0.37 | 114 36 4 2040.5 1.41 53 18 1001 2197.6 1.10 | 117 36 3 2036.4 0.49 55 36 5 2073.1 0.33 | 118 15 999 2185.3 1.56 56 36 5 2075.5 0.07 | 121 18 5 2023.1 0.45 57 36 5 2072.2 1.03 | 122 18 4 2014.1 0.45 59 17 1000 2197.5 1.63 | 123 20 3 2013.4 0.81 60 36 4 2075.7 0.90 | 124 21 4 2006.8 0.63 61 36 4 2064.1 0.16 | 125 23 4 2007.7 0.47 62 18 999 2194.8 1.41 | 126 21 3 2011.0 0.04 62 36 3 2066.6 0.18 | 127 20 4 2016.7 0.16 65 36 6 2065.9 0.46 | 129 11 4 2026.3 0.13 TABLE 4. Replicate pCO2 analyses STATION Bottle Latitude Longitude Depth Ave (fCO2,20C) Stdev(fCO2,20C) (°N) (°W) (m) (µatm) (µatm) ---------------------------------------------------------------------------- 2 10 28 13 149 480.1 2.05 6 30 28 14 3 361.7 5.59 7 12 27 15 849 881.1 3.11 8 17 27 16 847 803.0 5.23 8 33 27 16 3 344.1 0.14 10 32 27 17 117 392.5 6.79 13 15 26 18 1201 863.0 0.71 14 17 26 19 800 950.8 3.11 18 16 25 21 1229 827.3 0.57 19 18 25 21 1000 953.0 4.60 21 3 25 23 4499 752.0 0.64 22 26 25 23 449 691.3 1.63 23 10 24 24 2879 743.1 7.14 24 36 25 25 3 338.1 4.17 25 13 25 26 2497 733.8 4.88 27 36 24 27 4 318.4 2.83 28 18 25 28 1201 854.9 5.52 30 18 24 29 1000 872.6 11.88 30 30 24 29 248 418.4 0.28 34 5 25 33 4589 531.7 318.83 34 12 25 33 2401 741.1 2.69 34 14 25 33 2002 746.4 3.61 38 17 25 36 1250 831.4 13.65 39 12 25 37 2096 735.1 0.71 40 36 25 38 4 312.2 8.56 42 14 25 39 1999 742.9 7.78 43 8 25 40 2949 680.4 13.08 45 5 25 41 4051 706.1 5.16 45 13 25 41 2050 685.9 10.82 46 4 25 42 4000 691.8 7.99 47 5 25 42 3098 712.2 27.79 47 9 25 42 2092 676.5 7.07 48 36 25 43 7 289.9 29.63 49 5 25 43 3201 715.0 7.42 49 10 25 43 2198 698.2 2.97 50 5 25 43 3092 704.4 10.68 51 14 25 44 1500 743.3 25.24 51 34 25 44 100 253.7 0.64 52 36 25 45 7 316.9 44.90 53 8 25 45 2000 711.8 13.22 53 19 25 45 901 851.9 4.95 53 36 25 45 6 267.9 18.10 54 36 25 46 5 272.3 10.25 55 9 25 47 1999 726.2 8.13 56 36 25 47 5 283.8 1.41 57 36 25 48 5 278.4 0.71 58 20 25 48 902 844.0 15.06 58 21 25 48 802 777.8 17.96 58 22 25 48 700 689.0 20.36 58 29 25 48 276 385.5 11.74 58 36 25 48 5 262.5 18.60 59 36 25 49 4 277.7 1.84 60 36 25 49 4 278.2 25.31 61 36 24 50 4 274.1 2.40 62 36 25 50 3 274.1 2.26 TABLE 4. Replicate pCO2 analyses (continued) STATION Bottle Latitude Longitude Depth Ave (fCO2,20C) Stdev(fCO2,20C) (°N) (°W) (m) (µatm) (µatm) ---------------------------------------------------------------------------- 64 1 25 52 5363 733.8 8.27 65 36 25 51 6 276.4 1.70 66 16 25 53 1248 809.2 5.16 67 6 24 53 3999 743.7 6.01 67 13 24 53 1951 725.5 15.77 67 20 24 53 802 784.3 0.57 67 30 24 53 248 380.8 4.81 67 36 24 53 5 261.1 10.32 68 35 25 54 3 266.5 6.23 69 19 24 54 1051 848.9 5.80 70 1 24 55 6008 798.2 5.09 70 16 24 55 1402 743.8 1.20 70 36 24 55 5 260.2 4.24 71 2 25 56 6050 794.8 4.03 72 36 25 57 4 275.5 2.05 73 12 25 57 1900 721.2 7.35 74 6 25 58 3900 730.5 4.95 75 36 25 59 5 276.2 6.43 76 36 25 60 6 272.2 0.07 77 4 25 60 4698 691.1 67.18 79 1 25 62 5891 794.9 3.68 80 36 25 64 6 263.6 3.04 81 6 24 63 3966 736.2 2.40 82 1 25 64 5862 785.8 3.11 82 16 25 64 1049 840.5 1.48 83 13 25 65 1851 708.1 4.95 84 36 25 65 6 275.6 1.56 85 13 25 65 2101 720.4 8.41 86 1 25 67 5816 792.9 4.95 86 26 25 67 400 446.3 3.96 87 2 25 68 5291 784.6 4.81 88 36 25 68 5 275.1 0.35 89 1 25 69 5736 789.8 7.92 90 4 25 70 4450 740.8 9.55 91 36 25 70 5 283.8 0.49 94 3 27 71 4840 733.1 7.78 94 30 27 71 225 374.2 5.87 95 36 27 71 4 282.4 3.61 97 11 27 72 1998 725.7 3.46 98 1 27 72 5263 762.5 5.37 99 36 27 73 5 285.4 1.84 101 36 27 74 4 294.5 0.28 102 25 27 74 349 376.2 2.19 103 36 27 74 4 297.7 1.56 107 36 27 75 4 292.8 3.32 108 1 27 76 4751 748.1 6.22 110 34 27 76 96 301.3 3.25 111 36 27 76 4 285.8 0.42 113 36 26 76 3 287.6 3.32 114 3 27 76 4100 735.0 3.11 115 36 27 77 4 289.3 1.06 116 3 27 77 4188 736.3 5.37 117 36 27 77 3 288.9 1.70 120 3 27 77 1300 765.7 9.69 121 3 27 77 351 412.4 3.75 123 20 27 79 3 282.8 5.30 124 21 27 79 4 276.3 2.19 126 21 27 80 3 278.2 1.91 127 20 27 80 4 281.4 1.48 130 6 28 80 3 304.9 2.62 TABLE 5. Correction factors applied to raw data based upon carbonate parameters for Certified Reference Materials CRM TA pH (mmol/kg) ==================================================== Batch #40 2196.4 7.91 ---------------------------------------------------- CELL TA pH (mmol/kg) ---------------------------------------------------- Measured C.F. Measured C.F. N 2193.2 ± 1.2 1.001489 7.883 ± 0.004 0.026 12 2a 2198.5 ± 1.3 0.999062 7.883 ± 0.005 0.027 19 2193.0 ± 1.3 1.001547 7.872 ± 0.004 0.039 11 12 2194.7 ± 2.7 1.000779 7.875 ± 0.006 0.035 4 18b 2200.3 ± 3.0 0.998228 7.874 ± 0.002 0.032 10 21 2198.9 ± 0.9 0.998863 7.859 ± 0.005 0.051 48 a. Three slightly different correction factors were applied to cell 2 due to the change in volume from a broken piston. b. The weighted average was used TAcorr = TAsample x C.F. (TA) pHcorr = pHsample + C.F.(pH) TABLE 6. Replicate dissolved CFC-11 and CFC-12 analyses STN BTL CFC-11 CFC-11 CFC-12 CFC-12 | STN BTL CFC-11 CFC-11 CFC-12 CFC-12 NO NO pmol/kg Stdev pmol/kg Stdev | NO NO pmol/kg Stdev pmol/kg Stdev --- --- ------- ------ ------- ------ | --- --- ------- ------ ------- ------ 3 9 2.227 0.025 1.189 0.005 | 54 34 1.937 0.007 1.106 0.011 5 6 0.184 0.006 0.092 0.004 | 56 23 0.801 0.008 0.426 0.001 7 14 0.814 0.012 0.415 0.001 | 58 1 0.015 0.001 0.016 0.003 7 28 2.348 0.018 1.325 0.009 | 58 14 0.117 0.001 0.067 0.006 8 27 2.403 0.040 1.319 0.016 | 58 23 1.506 0.017 0.781 0.011 9 6 0.012 0.005 0.012 0.001 | 58 32 2.278 0.021 1.290 0.006 9 30 2.253 0.021 1.306 0.032 | 60 2 0.010 0.001 0.012 0.004 11 12 0.147 0.004 0.092 0.013 | 60 16 0.245 0.007 0.136 0.006 11 18 0.468 0.002 0.242 0.003 | 60 26 2.298 0.028 1.244 0.011 11 33 2.228 0.010 1.295 0.009 | 62 2 0.012 0.001 0.007 0.001 13 28 2.352 0.013 1.301 0.002 | 62 14 0.098 0.000 0.056 0.001 14 6 0.001 0.003 -9.000 -9.000 | 62 28 2.316 0.004 1.291 0.008 14 32 2.159 0.018 1.221 0.010 | 64 18 0.168 0.003 0.091 0.003 16 19 0.141 0.001 -9.000 -9.000 | 66 1 0.019 0.001 0.014 0.001 16 30 2.286 0.008 1.305 0.001 | 66 20 0.524 0.004 0.276 0.002 19 5 0.008 0.000 0.005 0.001 | 66 30 2.336 0.001 1.308 0.004 19 29 2.445 0.008 1.310 0.027 | 68 33 2.090 0.002 1.182 0.001 21 19 0.135 0.005 0.077 0.006 | 70 1 0.026 0.002 0.021 0.000 22 5 0.004 0.001 -0.001 0.003 | 70 20 0.211 0.001 0.114 0.001 22 17 0.030 0.006 0.010 0.004 | 70 22 0.748 0.001 0.386 0.002 22 34 2.088 0.004 1.401 0.003 | 70 32 2.308 0.006 1.283 0.001 24 1 0.003 0.001 0.001 0.001 | 72 21 0.334 0.004 0.180 0.005 24 18 0.054 0.001 0.031 0.004 | 74 5 0.033 0.001 0.018 0.001 24 22 0.144 0.000 0.085 0.003 | 74 16 0.355 0.003 0.184 0.003 24 35 2.247 0.030 1.407 0.013 | 74 32 2.286 0.000 1.284 0.001 26 2 0.001 0.001 0.000 0.001 | 76 34 2.105 0.001 1.193 0.005 26 12 0.007 0.000 -9.000 -9.000 | 78 2 0.031 0.002 0.023 0.001 26 14 0.010 0.003 0.003 0.002 | 78 16 0.219 0.003 0.122 0.001 26 24 2.161 0.019 1.132 0.006 | 78 27 2.338 0.000 1.295 0.005 26 35 1.978 0.013 1.143 0.010 | 80 28 2.327 0.001 1.284 0.006 28 9 0.002 0.001 -0.002 0.001 | 81 8 0.073 0.001 0.039 0.003 28 17 0.039 0.001 0.021 0.001 | 82 6 0.062 0.001 0.029 0.000 28 22 0.652 0.011 0.331 0.002 | 82 13 0.219 0.001 0.115 0.003 28 30 2.358 0.016 1.324 0.012 | 82 21 0.952 0.003 0.488 0.000 29 2 0.002 0.001 -0.004 0.006 | 82 32 2.334 0.001 1.306 0.000 29 23 1.609 0.001 0.827 0.001 | 84 5 0.151 0.001 0.080 0.001 30 1 0.000 0.000 -0.003 0.002 | 86 5 0.121 0.001 0.068 0.001 30 19 0.143 0.001 0.078 0.004 | 86 14 0.793 0.009 0.390 0.001 30 28 2.370 0.018 1.294 0.009 | 86 30 2.295 0.004 1.265 0.005 30 35 2.015 0.012 1.167 0.008 | 88 17 0.712 0.005 0.352 0.006 31 30 2.372 0.006 1.317 0.007 | 88 31 2.221 0.009 1.223 0.004 32 1 0.002 0.000 -0.001 0.004 | 90 7 0.150 0.000 0.081 0.001 32 20 0.137 0.000 0.064 0.004 | 90 20 0.708 0.002 0.364 0.004 32 34 2.033 0.007 1.172 0.001 | 92 14 0.216 0.006 0.113 0.003 34 21 0.367 0.001 0.171 0.002 | 92 16 0.302 0.000 0.159 0.001 34 34 1.962 0.012 1.137 0.005 | 92 26 2.207 0.003 1.188 0.000 35 4 0.001 0.000 0.004 0.001 | 92 32 2.222 0.003 1.248 0.004 35 18 0.055 0.001 0.025 0.001 | 94 5 0.324 0.003 0.165 0.001 35 33 2.310 0.026 1.316 0.008 | 94 15 0.770 0.002 0.381 0.001 36 2 0.001 0.001 -0.001 0.001 | 94 26 2.312 0.003 1.261 0.006 36 14 0.005 0.001 -0.001 0.003 | 96 6 0.410 0.001 0.206 0.000 36 34 1.978 0.006 1.145 0.004 | 96 28 2.319 0.023 1.288 0.016 37 21 0.090 0.000 0.039 0.001 | 98 6 0.614 0.004 0.298 0.001 37 31 2.348 0.010 1.330 0.008 | 98 18 0.321 0.002 0.167 0.003 38 12 0.000 0.000 -0.004 0.001 | 98 26 2.321 0.004 1.270 0.007 38 22 0.766 0.001 0.361 0.006 | 100 16 0.997 0.006 0.486 0.004 38 30 2.375 0.013 1.315 0.008 | 100 25 2.251 0.125 1.227 0.093 39 7 0.001 0.000 -0.004 0.002 | 102 15 0.990 0.004 0.486 0.002 39 24 2.049 0.008 1.064 0.001 | 102 24 2.197 0.066 1.196 0.042 40 1 0.003 0.001 0.002 0.001 | 104 3 0.508 0.003 0.248 0.006 40 22 1.307 0.016 0.641 0.004 | 104 29 2.303 0.000 1.263 0.003 40 28 2.361 0.001 1.297 0.004 | 106 18 0.269 0.001 0.142 0.000 42 4 0.001 0.002 -0.001 0.001 | 108 16 0.972 0.004 0.476 0.001 42 26 2.270 0.004 1.229 0.006 | 108 26 2.321 0.011 1.271 0.003 42 34 2.071 0.001 1.192 0.001 | 110 3 0.515 0.005 0.253 0.000 44 33 2.314 0.010 1.328 0.002 | 110 32 2.284 0.017 1.294 0.010 46 6 0.001 0.001 -0.001 0.004 | 112 18 0.331 0.001 0.167 0.001 46 20 0.567 0.001 0.275 0.001 | 112 30 2.074 0.004 1.190 0.004 46 32 2.266 0.034 1.288 0.016 | 114 2 0.524 0.178 0.259 0.078 48 1 0.003 0.001 0.003 0.001 | 114 13 1.245 0.007 0.609 0.001 48 3 0.001 0.000 0.003 0.004 | 114 24 2.370 0.019 1.328 0.010 48 20 0.138 0.002 0.067 0.004 | 116 8 0.610 0.122 0.301 0.061 48 31 2.253 0.014 1.277 0.021 | 116 16 1.190 0.001 0.585 0.004 48 34 1.908 0.008 1.098 0.000 | 116 26 2.192 0.002 1.198 0.013 50 1 0.001 0.000 0.001 0.001 | 118 10 0.862 0.368 0.420 0.180 50 20 0.920 0.003 0.466 0.002 | 118 12 1.164 0.008 0.568 0.001 50 30 2.310 0.064 1.269 0.062 | 118 22 2.265 0.001 1.238 0.001 52 14 0.123 0.000 0.067 0.001 | 120 16 1.655 0.371 0.867 0.204 52 23 1.566 0.004 0.810 0.002 | 120 20 2.224 0.117 1.248 0.040 54 4 0.023 0.001 0.016 0.005 | 125 10 1.673 0.001 0.891 0.001 54 16 0.109 0.001 0.057 0.002 | 125 22 1.715 0.004 1.005 0.001 54 28 2.306 0.015 1.262 0.013 | 129 7 2.069 0.008 1.180 0.007 TABLE 7. Replicate dissolved CFC-113 and CCL4 analyses STN BTL CFC-113 CFC-113 CCL4 CCL4 | STN BTL CFC-113 CFC-113 CCL4 CCL4 NO NO pmol/kg Stdev pmol/kg Stdev | NO NO pmol/kg Stdev pmol/kg Stdev --- --- ------- ------- ------- ------ | --- --- ------- ------- ------- ----- 3 9 0.043 0.024 -9.000 -9.000 | 62 14 0.005 0.001 -9.000 -9.000 5 6 0.002 0.006 -9.000 -9.000 | 62 28 0.035 0.001 -9.000 -9.000 7 14 0.018 0.006 -9.000 -9.000 | 64 1 -9.000 -9.000 0.127 0.006 7 28 0.178 0.008 -9.000 -9.000 | 64 2 -9.000 -9.000 0.131 0.003 8 27 0.056 0.006 -9.000 -9.000 | 64 18 0.006 0.002 -9.000 -9.000 9 6 0.000 0.000 -9.000 -9.000 | 64 33 -9.000 -9.000 0.844 0.039 9 30 0.174 0.008 -9.000 -9.000 | 66 1 0.006 0.002 -9.000 -9.000 11 12 -0.003 0.001 -9.000 -9.000 | 66 20 0.008 0.002 -9.000 -9.000 11 18 0.001 0.004 -9.000 -9.000 | 66 30 0.035 0.006 -9.000 -9.000 11 33 0.156 0.008 -9.000 -9.000 | 68 1 -9.000 -9.000 0.199 0.004 13 28 0.055 0.004 -9.000 -9.000 | 68 3 -9.000 -9.000 0.190 0.001 14 6 0.000 0.000 -9.000 -9.000 | 68 33 0.162 0.008 -9.000 -9.000 14 32 0.172 0.005 -9.000 -9.000 | 70 1 -0.002 0.002 -9.000 -9.000 16 19 0.000 0.000 -9.000 -9.000 | 70 20 0.005 0.001 -9.000 -9.000 16 30 0.051 0.001 -9.000 -9.000 | 70 22 0.013 0.006 -9.000 -9.000 19 5 0.001 0.001 -9.000 -9.000 | 70 32 0.038 0.009 -9.000 -9.000 19 29 0.029 0.008 -9.000 -9.000 | 72 1 -9.000 -9.000 0.205 0.001 21 19 -0.004 0.000 -9.000 -9.000 | 72 4 -9.000 -9.000 0.408 0.004 22 5 0.001 0.001 -9.000 -9.000 | 72 14 -9.000 -9.000 0.342 0.181 22 17 -0.004 0.005 -9.000 -9.000 | 72 17 -9.000 -9.000 0.451 0.011 22 34 0.157 0.008 -9.000 -9.000 | 72 21 0.006 0.001 -9.000 -9.000 24 1 -0.002 0.001 -9.000 -9.000 | 72 35 -9.000 -9.000 1.935 0.043 24 18 -0.005 0.002 -9.000 -9.000 | 74 4 -9.000 -9.000 0.327 0.008 24 22 -0.001 0.006 -9.000 -9.000 | 74 5 0.012 0.001 -9.000 -9.000 24 35 0.163 0.007 -9.000 -9.000 | 74 16 0.011 0.001 -9.000 -9.000 26 2 -0.002 0.001 -9.000 -9.000 | 74 32 0.078 0.007 -9.000 -9.000 26 12 0.006 0.001 -9.000 -9.000 | 76 2 0.007 0.001 -9.000 -9.000 26 14 0.005 0.007 -9.000 -9.000 | 76 4 -9.000 -9.000 0.294 0.004 26 24 0.023 0.004 -9.000 -9.000 | 76 8 -9.000 -9.000 0.143 0.005 26 35 0.166 0.002 -9.000 -9.000 | 76 25 -9.000 -9.000 0.436 0.003 28 9 -0.006 0.001 -9.000 -9.000 | 78 2 0.007 0.001 -9.000 -9.000 28 17 0.001 0.002 -9.000 -9.000 | 78 16 0.008 0.001 -9.000 -9.000 28 22 0.004 0.002 -9.000 -9.000 | 78 27 0.035 0.000 -9.000 -9.000 28 30 0.059 0.004 -9.000 -9.000 | 80 13 -9.000 -9.000 0.944 0.016 29 2 -0.004 0.002 -9.000 -9.000 | 80 28 0.039 0.005 -9.000 -9.000 29 23 0.015 0.005 -9.000 -9.000 | 80 33 -9.000 -9.000 0.822 0.010 30 1 -0.003 0.004 -9.000 -9.000 | 81 8 0.006 0.001 -9.000 -9.000 30 19 -0.001 0.001 -9.000 -9.000 | 82 6 0.004 0.002 -9.000 -9.000 30 28 0.031 0.005 -9.000 -9.000 | 82 13 0.008 0.002 -9.000 -9.000 30 35 0.176 0.001 -9.000 -9.000 | 82 21 0.012 0.001 -9.000 -9.000 31 30 0.039 0.002 -9.000 -9.000 | 82 32 0.056 0.001 -9.000 -9.000 32 1 -0.005 0.001 -9.000 -9.000 | 84 4 -9.000 -9.000 0.455 0.006 32 20 -0.002 0.010 -9.000 -9.000 | 84 5 0.010 0.006 -9.000 -9.000 32 34 0.160 0.011 -9.000 -9.000 | 84 34 -9.000 -9.000 1.751 0.012 33 1 -9.000 -9.000 0.031 0.001 | 86 5 0.005 0.003 -9.000 -9.000 33 26 -9.000 -9.000 0.451 0.002 | 86 14 0.030 0.001 -9.000 -9.000 33 35 -9.000 -9.000 1.912 0.046 | 86 30 0.024 0.003 -9.000 -9.000 34 21 0.004 0.004 -9.000 -9.000 | 88 4 -9.000 -9.000 0.533 0.011 34 34 0.169 0.006 -9.000 -9.000 | 88 17 0.022 0.002 -9.000 -9.000 35 4 -0.003 0.000 -9.000 -9.000 | 88 31 0.030 0.006 -9.000 -9.000 TABLE 7. Replicate dissolved CFC-113 and CCL4 analyses (continued) STN BTL CFC-113 CFC-113 CCL4 CCL4 | STN BTL CFC-113 CFC-113 CCL4 CCL4 NO NO pmol/kg Stdev pmol/kg Stdev | NO NO pmol/kg Stdev pmol/kg Stdev --- --- ------- ------- ------- ------ | --- --- ------- ------- ------- ----- 35 18 -0.009 0.002 -9.000 -9.000 | 88 33 -9.000 -9.000 0.463 0.006 35 33 0.140 0.004 -9.000 -9.000 | 90 4 -9.000 -9.000 0.865 0.006 36 2 -0.002 0.004 -9.000 -9.000 | 90 7 0.006 0.005 -9.000 -9.000 36 3 -9.000 -9.000 0.021 0.002 | 90 20 0.010 0.000 -9.000 -9.000 36 14 -0.004 0.000 -9.000 -9.000 | 92 5 -9.000 -9.000 0.654 0.294 36 18 -9.000 -9.000 0.086 0.006 | 92 14 0.005 0.003 -9.000 -9.000 36 33 -9.000 -9.000 1.095 0.032 | 92 16 0.008 0.003 -9.000 -9.000 36 34 0.154 0.003 -9.000 -9.000 | 92 26 0.026 0.004 -9.000 -9.000 37 21 0.002 0.005 -9.000 -9.000 | 92 32 0.055 0.005 -9.000 -9.000 37 31 0.067 0.001 -9.000 -9.000 | 94 5 0.020 0.001 -9.000 -9.000 38 12 0.002 0.001 -9.000 -9.000 | 94 6 -9.000 -9.000 0.884 0.002 38 22 0.011 0.005 -9.000 -9.000 | 94 15 0.033 0.002 -9.000 -9.000 38 30 0.038 0.003 -9.000 -9.000 | 94 26 0.027 0.003 -9.000 -9.000 39 7 -0.001 0.001 -9.000 -9.000 | 96 4 -9.000 -9.000 0.988 0.001 39 10 -9.000 -9.000 0.022 0.006 | 96 6 0.018 0.001 -9.000 -9.000 39 24 0.032 0.001 -9.000 -9.000 | 96 28 0.037 0.001 -9.000 -9.000 39 29 -9.000 -9.000 0.566 0.008 | 98 4 -9.000 -9.000 1.169 0.028 40 1 -0.001 0.001 -9.000 -9.000 | 98 6 0.024 0.000 -9.000 -9.000 40 22 0.021 0.002 -9.000 -9.000 | 98 18 0.010 0.006 -9.000 -9.000 40 28 0.031 0.001 -9.000 -9.000 | 98 26 0.033 0.008 -9.000 -9.000 42 4 0.001 0.001 -9.000 -9.000 | 100 4 -9.000 -9.000 1.051 0.006 42 26 0.029 0.001 -9.000 -9.000 | 100 16 0.036 0.001 -9.000 -9.000 42 34 0.182 0.012 -9.000 -9.000 | 100 25 0.037 0.008 -9.000 -9.000 43 1 -9.000 -9.000 0.035 0.001 | 102 6 -9.000 -9.000 1.135 0.006 43 19 -9.000 -9.000 0.227 0.013 | 102 15 0.043 0.001 -9.000 -9.000 43 34 -9.000 -9.000 1.036 0.016 | 102 24 0.041 0.004 -9.000 -9.000 44 33 0.154 0.001 -9.000 -9.000 | 104 3 0.032 0.007 -9.000 -9.000 46 6 -0.001 0.001 -9.000 -9.000 | 104 4 -9.000 -9.000 1.105 0.007 46 20 0.008 0.001 -9.000 -9.000 | 104 29 0.021 0.001 -9.000 -9.000 46 32 0.091 0.006 -9.000 -9.000 | 104 32 -9.000 -9.000 0.607 0.318 47 1 -9.000 -9.000 0.028 0.001 | 104 34 -9.000 -9.000 2.017 0.059 47 31 -9.000 -9.000 0.956 0.011 | 106 12 -9.000 -9.000 1.044 0.000 48 1 0.003 0.001 -9.000 -9.000 | 106 18 0.003 0.001 -9.000 -9.000 48 3 0.002 0.002 -9.000 -9.000 | 108 16 0.039 0.006 -9.000 -9.000 48 20 0.002 0.001 -9.000 -9.000 | 108 26 0.022 0.003 -9.000 -9.000 48 31 0.112 0.008 -9.000 -9.000 | 110 3 0.028 0.001 -9.000 -9.000 48 34 0.188 0.013 -9.000 -9.000 | 110 5 -9.000 -9.000 1.249 0.013 50 20 0.009 0.001 -9.000 -9.000 | 110 26 -9.000 -9.000 0.639 0.012 50 30 0.023 0.033 -9.000 -9.000 | 110 32 0.103 0.005 -9.000 -9.000 51 1 -9.000 -9.000 0.067 0.013 | 112 18 0.006 0.007 -9.000 -9.000 51 17 -9.000 -9.000 0.230 0.009 | 112 30 0.164 0.004 -9.000 -9.000 51 26 -9.000 -9.000 0.442 0.042 | 114 2 0.028 0.001 -9.000 -9.000 52 14 0.005 0.005 -9.000 -9.000 | 114 4 -9.000 -9.000 1.241 0.020 52 23 0.017 0.004 -9.000 -9.000 | 114 6 -9.000 -9.000 1.129 0.028 54 4 0.001 0.002 -9.000 -9.000 | 114 13 0.055 0.001 -9.000 -9.000 54 16 0.005 0.001 -9.000 -9.000 | 114 24 0.059 0.001 -9.000 -9.000 54 28 0.031 0.004 -9.000 -9.000 | 116 8 0.021 0.007 -9.000 -9.000 54 34 0.182 0.025 -9.000 -9.000 | 116 10 -9.000 -9.000 0.996 0.002 56 23 0.010 0.006 -9.000 -9.000 | 116 16 0.052 0.001 -9.000 -9.000 56 27 -9.000 -9.000 0.451 0.012 | 116 26 0.030 0.001 -9.000 -9.000 58 1 0.002 0.003 -9.000 -9.000 | 118 4 -9.000 -9.000 1.128 0.026 58 14 0.008 0.002 -9.000 -9.000 | 118 10 0.049 0.017 -9.000 -9.000 58 23 0.020 0.000 -9.000 -9.000 | 118 12 0.058 0.007 -9.000 -9.000 58 32 0.081 0.003 -9.000 -9.000 | 118 22 0.033 0.002 -9.000 -9.000 60 2 0.002 0.001 -9.000 -9.000 | 120 16 0.017 0.005 -9.000 -9.000 60 5 -9.000 -9.000 0.130 0.008 | 120 20 0.045 0.035 0.429 0.015 60 16 0.007 0.001 -9.000 -9.000 | 125 8 -9.000 -9.000 0.270 0.008 60 26 0.035 0.003 -9.000 -9.000 | 125 22 0.145 0.003 -9.000 -9.000 60 33 -9.000 -9.000 1.077 0.017 | 129 7 0.136 0.003 -9.000 -9.000 62 2 0.006 0.001 -9.000 -9.000 | 130 6 -9.000 -9.000 2.107 0.021 TABLE 8. CFC air measurements Date GMT Latitude Longitude CFC-11 CFC-12 CFC-113 CCL4 (hhmm) (°N) (°W) (ppt) (ppt) (ppt) (ppt) -------------------------------------------------------------------- 24-Jan-98 1840 27.433 14.850 259.836 535.550 79.192 -9.000 24-Jan-98 1851 27.433 14.851 260.321 537.726 79.103 -9.000 24-Jan-98 1902 27.433 14.851 261.361 534.915 77.644 -9.000 24-Jan-98 1913 27.433 14.851 261.377 536.906 77.760 -9.000 24-Jan-98 1924 27.424 14.891 262.772 537.277 77.314 -9.000 27-Jan-98 1946 24.909 22.448 262.927 540.885 79.736 -9.000 27-Jan-98 1956 24.876 22.532 263.902 543.954 82.513 -9.000 27-Jan-98 2006 24.871 22.547 263.581 547.197 78.311 -9.000 27-Jan-98 2026 24.840 22.632 263.681 548.454 79.922 -9.000 27-Jan-98 2036 24.834 22.646 264.611 549.683 78.559 -9.000 27-Jan-98 2046 24.834 22.646 265.075 549.246 77.953 -9.000 28-Jan-98 2106 24.500 24.961 263.434 537.866 79.534 -9.000 28-Jan-98 2116 24.501 25.026 262.535 538.353 77.246 -9.000 28-Jan-98 2126 24.503 25.062 263.367 540.686 78.619 -9.000 28-Jan-98 2146 24.504 25.080 262.361 538.433 78.813 -9.000 28-Jan-98 2156 24.503 25.182 259.377 534.339 79.203 -9.000 28-Jan-98 2206 24.503 25.199 259.908 536.414 77.986 -9.000 29-Jan-98 1239 24.500 26.755 265.207 539.051 77.299 -9.000 29-Jan-98 1309 24.499 26.869 264.325 543.569 81.042 -9.000 29-Jan-98 1319 24.501 26.932 265.751 543.250 81.041 -9.000 29-Jan-98 1329 24.501 26.966 261.947 539.318 81.010 -9.000 29-Jan-98 1339 24.500 26.983 264.225 543.042 78.873 -9.000 29-Jan-98 1420 24.500 27.146 265.708 542.256 81.572 -9.000 31-Jan-98 2100 24.500 32.733 260.684 533.662 80.721 -9.000 31-Jan-98 2110 24.500 32.733 262.469 537.215 80.101 -9.000 31-Jan-98 2120 24.500 32.733 260.907 533.539 78.561 -9.000 31-Jan-98 2150 24.500 32.750 258.837 532.814 77.423 -9.000 31-Jan-98 2200 24.500 32.784 263.848 541.865 77.622 -9.000 31-Jan-98 2210 24.500 32.801 259.333 532.263 77.621 -9.000 1-Feb-98 1413 24.502 34.383 -9.000 -9.000 -9.000 89.351 1-Feb-98 1433 24.502 34.383 -9.000 -9.000 -9.000 85.866 1-Feb-98 1453 24.502 34.383 -9.000 -9.000 -9.000 84.658 3-Feb-98 1515 24.500 39.983 262.053 536.784 79.448 -9.000 3-Feb-98 1525 24.498 39.996 262.736 536.844 78.944 -9.000 3-Feb-98 1535 24.498 40.029 261.965 536.178 78.790 -9.000 3-Feb-98 1545 24.498 40.029 261.492 536.176 79.798 -9.000 3-Feb-98 1615 24.501 40.143 262.094 539.114 77.696 -9.000 3-Feb-98 1625 24.501 40.240 261.884 539.831 78.942 -9.000 3-Feb-98 1803 24.500 40.533 -9.000 -9.000 -9.000 94.672 3-Feb-98 1823 24.500 40.533 -9.000 -9.000 -9.000 93.793 4-Feb-98 734 41.633 40.533 -9.000 -9.000 -9.000 92.265 4-Feb-98 754 41.633 40.533 -9.000 -9.000 -9.000 94.492 4-Feb-98 834 41.633 40.533 -9.000 -9.000 -9.000 91.098 4-Feb-98 854 41.633 40.533 -9.000 -9.000 -9.000 93.565 6-Feb-98 1137 24.500 47.134 -9.000 -9.000 -9.000 94.687 6-Feb-98 1157 24.500 47.134 -9.000 -9.000 -9.000 92.685 6-Feb-98 1237 24.500 47.134 -9.000 -9.000 -9.000 91.974 6-Feb-98 1257 24.500 47.134 -9.000 -9.000 -9.000 93.088 7-Feb-98 1224 24.500 49.333 262.958 538.920 79.104 -9.000 7-Feb-98 1234 24.500 49.333 261.579 540.095 80.068 -9.000 7-Feb-98 1244 24.500 49.333 261.338 538.346 79.588 -9.000 7-Feb-98 1314 24.500 49.333 265.800 540.404 81.139 -9.000 7-Feb-98 1324 24.500 49.333 262.774 539.189 79.657 -9.000 7-Feb-98 1334 24.500 49.333 262.934 539.476 79.559 -9.000 7-Feb-98 1531 24.500 49.461 258.404 531.774 78.156 -9.000 8-Feb-98 1914 24.501 51.533 261.171 537.612 80.509 -9.000 8-Feb-98 1924 24.500 51.533 262.143 538.129 79.696 -9.000 8-Feb-98 1934 24.499 51.546 265.034 538.779 80.208 -9.000 8-Feb-98 2004 24.500 51.636 262.012 536.424 80.017 -9.000 8-Feb-98 2014 24.500 51.636 261.953 537.730 79.940 -9.000 8-Feb-98 2024 24.499 51.699 263.807 538.928 79.901 -9.000 8-Feb-98 2056 24.501 51.533 -9.000 -9.000 -9.000 95.090 8-Feb-98 2116 24.501 51.533 -9.000 -9.000 -9.000 93.306 8-Feb-98 2156 24.501 51.533 -9.000 -9.000 -9.000 93.817 8-Feb-98 2216 24.501 51.533 -9.000 -9.000 -9.000 91.694 9-Feb-98 2244 24.502 53.784 261.719 537.661 81.545 -9.000 9-Feb-98 2254 24.504 53.851 262.597 539.557 80.872 -9.000 9-Feb-98 2304 24.504 53.880 261.726 537.667 79.912 -9.000 9-Feb-98 2324 24.503 53.956 264.344 541.163 80.720 -9.000 9-Feb-98 2334 24.502 53.987 262.269 536.927 80.020 -9.000 9-Feb-98 2344 24.502 53.987 262.205 536.721 80.565 -9.000 TABLE 8. CFC air measurements (continued) Date GMT Latitude Longitude CFC-11 CFC-12 CFC-113 CCL4 (hhmm) (°N) (°W) (ppt) (ppt) (ppt) (ppt) -------------------------------------------------------------------- 10-Feb-98 2032 24.500 55.933 -9.000 -9.000 -9.000 94.388 10-Feb-98 2052 24.500 55.933 -9.000 -9.000 -9.000 93.208 10-Feb-98 2112 24.500 55.933 -9.000 -9.000 -9.000 92.775 10-Feb-98 2132 24.500 55.933 -9.000 -9.000 -9.000 91.823 11-Feb-98 339 24.500 56.667 -9.000 -9.000 -9.000 94.978 11-Feb-98 359 24.500 56.667 -9.000 -9.000 -9.000 95.100 11-Feb-98 439 24.500 56.667 -9.000 -9.000 -9.000 93.361 11-Feb-98 459 24.500 56.667 -9.000 -9.000 -9.000 94.658 11-Feb-98 2204 24.500 58.134 -9.000 -9.000 -9.000 96.657 11-Feb-98 2224 24.500 58.134 -9.000 -9.000 -9.000 96.483 11-Feb-98 2244 24.500 58.134 -9.000 -9.000 -9.000 96.476 13-Feb-98 115 24.500 61.067 262.315 536.445 81.119 -9.000 13-Feb-98 125 24.500 61.067 262.475 538.298 82.255 -9.000 13-Feb-98 135 24.500 61.067 261.623 538.645 80.140 -9.000 13-Feb-98 155 24.506 61.071 261.686 538.295 79.729 -9.000 13-Feb-98 205 24.505 61.105 262.698 538.700 80.228 -9.000 13-Feb-98 215 24.505 61.105 261.676 536.758 79.115 -9.000 13-Feb-98 229 24.500 61.801 -9.000 -9.000 -9.000 93.299 13-Feb-98 249 24.500 61.801 -9.000 -9.000 -9.000 94.033 13-Feb-98 329 24.500 61.801 -9.000 -9.000 -9.000 94.533 13-Feb-98 349 24.500 61.801 -9.000 -9.000 -9.000 95.347 14-Feb-98 1944 24.500 65.468 262.707 539.047 80.631 -9.000 14-Feb-98 1954 24.500 65.467 262.465 538.199 81.209 -9.000 14-Feb-98 2004 24.501 65.467 262.275 536.354 80.125 -9.000 14-Feb-98 2024 24.500 65.467 262.132 536.824 80.285 -9.000 14-Feb-98 2034 24.501 65.467 262.028 537.808 80.243 -9.000 14-Feb-98 2044 24.501 65.467 262.004 537.114 80.121 -9.000 16-Feb-98 146 24.504 68.440 262.523 540.348 80.763 -9.000 16-Feb-98 156 24.503 68.544 263.901 539.621 81.137 -9.000 16-Feb-98 206 24.502 68.562 261.984 538.864 79.805 -9.000 16-Feb-98 226 24.498 68.666 263.276 540.683 79.877 -9.000 16-Feb-98 236 24.498 68.684 263.034 541.216 79.900 -9.000 16-Feb-98 246 24.498 68.684 263.002 541.274 80.052 -9.000 16-Feb-98 250 24.500 69.133 -9.000 -9.000 -9.000 94.950 16-Feb-98 310 24.500 69.133 -9.000 -9.000 -9.000 95.214 16-Feb-98 330 24.500 69.133 -9.000 -9.000 -9.000 93.795 19-Feb-98 25 26.500 73.216 262.293 538.847 80.539 -9.000 19-Feb-98 35 26.500 73.217 262.142 538.710 80.844 -9.000 19-Feb-98 45 26.500 73.217 261.824 539.329 80.451 -9.000 19-Feb-98 55 26.501 73.309 262.074 540.199 80.325 -9.000 19-Feb-98 110 26.500 73.583 -9.000 -9.000 -9.000 96.505 19-Feb-98 130 26.500 73.583 -9.000 -9.000 -9.000 96.064 19-Feb-98 150 26.500 73.583 -9.000 -9.000 -9.000 95.901 19-Feb-98 210 26.500 73.583 -9.000 -9.000 -9.000 94.810 20-Feb-98 1324 26.500 75.500 -9.000 -9.000 -9.000 96.687 20-Feb-98 1344 26.500 75.500 -9.000 -9.000 -9.000 95.869 20-Feb-98 1424 26.500 75.500 -9.000 -9.000 -9.000 95.886 20-Feb-98 1444 26.500 75.500 -9.000 -9.000 -9.000 95.399 20-Feb-98 2333 26.500 75.900 -9.000 -9.000 -9.000 96.398 20-Feb-98 2353 26.500 75.900 -9.000 -9.000 -9.000 95.629 21-Feb-98 1549 26.510 76.427 262.483 540.744 80.515 -9.000 21-Feb-98 1559 26.510 76.428 262.273 539.635 80.446 -9.000 21-Feb-98 1609 26.511 76.428 262.793 541.135 80.816 -9.000 21-Feb-98 1629 26.514 76.431 262.827 538.937 79.301 -9.000 21-Feb-98 1639 26.516 76.434 263.024 538.655 78.736 -9.000 21-Feb-98 1649 26.508 76.482 262.900 538.355 79.284 -9.000 22-Feb-98 108 26.500 76.617 261.254 537.878 79.587 -9.000 22-Feb-98 152 26.500 76.683 260.123 536.113 78.455 -9.000 22-Feb-98 234 26.500 76.683 -9.000 -9.000 -9.000 96.873 22-Feb-98 254 26.500 76.683 -9.000 -9.000 -9.000 96.657 23-Feb-98 237 26.111 78.494 264.570 540.167 81.155 -9.000 23-Feb-98 247 26.111 78.494 264.310 539.409 80.459 -9.000 23-Feb-98 257 26.163 78.587 262.826 539.090 79.707 -9.000 23-Feb-98 307 26.168 78.606 262.319 538.885 79.498 -9.000 23-Feb-98 337 26.171 78.731 262.246 539.018 79.676 -9.000 23-Feb-98 539 27.001 79.200 -9.000 -9.000 -9.000 93.798 23-Feb-98 559 27.001 79.200 -9.000 -9.000 -9.000 93.073 23-Feb-98 619 27.001 79.200 -9.000 -9.000 -9.000 93.724 23-Feb-98 1401 27.038 79.481 -9.000 -9.000 -9.000 97.231 23-Feb-98 1421 27.038 79.481 -9.000 -9.000 -9.000 96.196 23-Feb-98 1441 27.038 79.481 -9.000 -9.000 -9.000 95.753 24-Feb-98 250 26.999 79.937 -9.000 -9.000 -9.000 97.861 24-Feb-98 310 26.999 79.937 -9.000 -9.000 -9.000 97.393 TABLE 9. CFC air values (interpolated to station locations) Station Date Latitude Longitude CFC-11 CFC-12 CFC-113 CCL4 (°N) (°W) (ppt) (ppt) (ppt) (ppt) -------------------------------------------------------------------- 6 24-Jan-98 27.433 14.850 259.836 535.550 79.192 -9.000 7 24-Jan-98 27.433 14.851 260.321 537.726 79.103 -9.000 7 24-Jan-98 27.433 14.851 261.361 534.915 77.644 -9.000 7 24-Jan-98 27.433 14.851 261.377 536.906 77.760 -9.000 7 24-Jan-98 27.424 14.891 262.772 537.277 77.314 -9.000 20 27-Jan-98 24.909 22.448 262.927 540.885 79.736 -9.000 20 27-Jan-98 24.876 22.532 263.902 543.954 82.513 -9.000 20 27-Jan-98 24.871 22.547 263.581 547.197 78.311 -9.000 20 27-Jan-98 24.840 22.632 263.681 548.454 79.922 -9.000 20 27-Jan-98 24.834 22.646 264.611 549.683 78.559 -9.000 20 27-Jan-98 24.834 22.646 265.075 549.246 77.953 -9.000 24 28-Jan-98 24.500 24.961 263.434 537.866 79.534 -9.000 24 28-Jan-98 24.501 25.026 262.535 538.353 77.246 -9.000 24 28-Jan-98 24.503 25.062 263.367 540.686 78.619 -9.000 24 28-Jan-98 24.504 25.080 262.361 538.433 78.813 -9.000 24 28-Jan-98 24.503 25.182 259.377 534.339 79.203 -9.000 24 28-Jan-98 24.503 25.199 259.908 536.414 77.986 -9.000 26 29-Jan-98 24.500 26.755 265.207 539.051 77.299 -9.000 26 29-Jan-98 24.499 26.869 264.325 543.569 81.042 -9.000 26 29-Jan-98 24.501 26.932 265.751 543.250 81.041 -9.000 26 29-Jan-98 24.501 26.966 261.947 539.318 81.010 -9.000 26 29-Jan-98 24.500 26.983 264.225 543.042 78.873 -9.000 26 29-Jan-98 24.500 27.146 265.708 542.256 81.572 -9.000 34 31-Jan-98 24.500 32.733 260.684 533.662 80.721 -9.000 34 31-Jan-98 24.500 32.733 262.469 537.215 80.101 -9.000 34 31-Jan-98 24.500 32.733 260.907 533.539 78.561 -9.000 34 31-Jan-98 24.500 32.750 258.837 532.814 77.423 -9.000 34 31-Jan-98 24.500 32.784 263.848 541.865 77.622 -9.000 34 31-Jan-98 24.500 32.801 259.333 532.263 77.621 -9.000 36 1-Feb-98 24.502 34.383 -9.000 -9.000 -9.000 89.351 36 1-Feb-98 24.502 34.383 -9.000 -9.000 -9.000 85.866 36 1-Feb-98 24.502 34.383 -9.000 -9.000 -9.000 84.658 42 3-Feb-98 24.500 39.983 262.053 536.784 79.448 -9.000 42 3-Feb-98 24.498 39.996 262.736 536.844 78.944 -9.000 42 3-Feb-98 24.498 40.029 261.965 536.178 78.790 -9.000 42 3-Feb-98 24.498 40.029 261.492 536.176 79.798 -9.000 42 3-Feb-98 24.501 40.143 262.094 539.114 77.696 -9.000 42 3-Feb-98 24.501 40.240 261.884 539.831 78.942 -9.000 44 3-Feb-98 24.500 40.533 -9.000 -9.000 -9.000 94.672 44 3-Feb-98 24.500 40.533 -9.000 -9.000 -9.000 93.793 44 4-Feb-98 41.633 40.533 -9.000 -9.000 -9.000 92.265 44 4-Feb-98 41.633 40.533 -9.000 -9.000 -9.000 94.492 44 4-Feb-98 41.633 40.533 -9.000 -9.000 -9.000 91.098 44 4-Feb-98 41.633 40.533 -9.000 -9.000 -9.000 93.565 56 6-Feb-98 24.500 47.134 -9.000 -9.000 -9.000 94.687 56 6-Feb-98 24.500 47.134 -9.000 -9.000 -9.000 92.685 56 6-Feb-98 24.500 47.134 -9.000 -9.000 -9.000 91.974 56 6-Feb-98 24.500 47.134 -9.000 -9.000 -9.000 93.088 60 7-Feb-98 24.500 49.333 262.958 538.920 79.104 -9.000 60 7-Feb-98 24.500 49.333 261.579 540.095 80.068 -9.000 60 7-Feb-98 24.500 49.333 261.338 538.346 79.588 -9.000 60 7-Feb-98 24.500 49.333 265.800 540.404 81.139 -9.000 60 7-Feb-98 24.500 49.333 262.774 539.189 79.657 -9.000 60 7-Feb-98 24.500 49.333 262.934 539.476 79.559 -9.000 60 7-Feb-98 24.500 49.461 258.404 531.774 78.156 -9.000 64 8-Feb-98 24.501 51.533 261.171 537.612 80.509 -9.000 64 8-Feb-98 24.500 51.533 262.143 538.129 79.696 -9.000 64 8-Feb-98 24.499 51.546 265.034 538.779 80.208 -9.000 64 8-Feb-98 24.500 51.636 262.012 536.424 80.017 -9.000 64 8-Feb-98 24.500 51.636 261.953 537.730 79.940 -9.000 64 8-Feb-98 24.499 51.699 263.807 538.928 79.901 -9.000 64 8-Feb-98 24.501 51.533 -9.000 -9.000 -9.000 95.090 64 8-Feb-98 24.501 51.533 -9.000 -9.000 -9.000 93.306 64 8-Feb-98 24.501 51.533 -9.000 -9.000 -9.000 93.817 64 8-Feb-98 24.501 51.533 -9.000 -9.000 -9.000 91.694 58 9-Feb-98 24.502 53.784 261.719 537.661 81.545 -9.000 58 9-Feb-98 24.504 53.851 262.597 539.557 80.872 -9.000 58 9-Feb-98 24.504 53.880 261.726 537.667 79.912 -9.000 58 9-Feb-98 24.503 53.956 264.344 541.163 80.720 -9.000 58 9-Feb-98 24.502 53.987 262.269 536.927 80.020 -9.000 TABLE 9. CFC air values (interpolated to station locations, continued) Station Date Latitude Longitude CFC-11 CFC-12 CFC-113 CCL4 (°N) (°W) (ppt) (ppt) (ppt) (ppt) -------------------------------------------------------------------- 58 9-Feb-98 24.502 53.987 262.205 536.721 80.565 -9.000 71 10-Feb-98 24.500 55.933 -9.000 -9.000 -9.000 94.388 71 10-Feb-98 24.500 55.933 -9.000 -9.000 -9.000 93.208 71 10-Feb-98 24.500 55.933 -9.000 -9.000 -9.000 92.775 71 10-Feb-98 24.500 55.933 -9.000 -9.000 -9.000 91.823 72 11-Feb-98 24.500 56.667 -9.000 -9.000 -9.000 94.978 72 11-Feb-98 24.500 56.667 -9.000 -9.000 -9.000 95.100 72 11-Feb-98 24.500 56.667 -9.000 -9.000 -9.000 93.361 72 11-Feb-98 24.500 56.667 -9.000 -9.000 -9.000 94.658 74 11-Feb-98 24.500 58.134 -9.000 -9.000 -9.000 96.657 74 11-Feb-98 24.500 58.134 -9.000 -9.000 -9.000 96.483 74 11-Feb-98 24.500 58.134 -9.000 -9.000 -9.000 96.476 79 13-Feb-98 24.500 61.067 262.315 536.445 81.119 -9.000 79 13-Feb-98 24.500 61.067 262.475 538.298 82.255 -9.000 79 13-Feb-98 24.500 61.067 261.623 538.645 80.140 -9.000 79 13-Feb-98 24.506 61.071 261.686 538.295 79.729 -9.000 79 13-Feb-98 24.505 61.105 262.698 538.700 80.228 -9.000 79 13-Feb-98 24.505 61.105 261.676 536.758 79.115 -9.000 79 13-Feb-98 24.500 61.801 -9.000 -9.000 -9.000 93.299 79 13-Feb-98 24.500 61.801 -9.000 -9.000 -9.000 94.033 79 13-Feb-98 24.500 61.801 -9.000 -9.000 -9.000 94.533 79 13-Feb-98 24.500 61.801 -9.000 -9.000 -9.000 95.347 84 14-Feb-98 24.500 65.468 262.707 539.047 80.631 -9.000 84 14-Feb-98 24.500 65.467 262.465 538.199 81.209 -9.000 84 14-Feb-98 24.501 65.467 262.275 536.354 80.125 -9.000 84 14-Feb-98 24.500 65.467 262.132 536.824 80.285 -9.000 84 14-Feb-98 24.501 65.467 262.028 537.808 80.243 -9.000 84 14-Feb-98 24.501 65.467 262.004 537.114 80.121 -9.000 88 16-Feb-98 24.504 68.440 262.523 540.348 80.763 -9.000 88 16-Feb-98 24.503 68.544 263.901 539.621 81.137 -9.000 88 16-Feb-98 24.502 68.562 261.984 538.864 79.805 -9.000 88 16-Feb-98 24.498 68.666 263.276 540.683 79.877 -9.000 88 16-Feb-98 24.498 68.684 263.034 541.216 79.900 -9.000 88 16-Feb-98 24.498 68.684 263.002 541.274 80.052 -9.000 89 16-Feb-98 24.500 69.133 -9.000 -9.000 -9.000 94.950 89 16-Feb-98 24.500 69.133 -9.000 -9.000 -9.000 95.214 89 16-Feb-98 24.500 69.133 -9.000 -9.000 -9.000 93.795 100 19-Feb-98 26.500 73.216 262.293 538.847 80.539 -9.000 100 19-Feb-98 26.500 73.217 262.142 538.710 80.844 -9.000 100 19-Feb-98 26.500 73.217 261.824 539.329 80.451 -9.000 100 19-Feb-98 26.501 73.309 262.074 540.199 80.325 -9.000 101 19-Feb-98 26.500 73.583 -9.000 -9.000 -9.000 96.505 101 19-Feb-98 26.500 73.583 -9.000 -9.000 -9.000 96.064 101 19-Feb-98 26.500 73.583 -9.000 -9.000 -9.000 95.901 101 19-Feb-98 26.500 73.583 -9.000 -9.000 -9.000 94.810 108 20-Feb-98 26.500 75.500 -9.000 -9.000 -9.000 96.687 108 20-Feb-98 26.500 75.500 -9.000 -9.000 -9.000 95.869 108 20-Feb-98 26.500 75.500 -9.000 -9.000 -9.000 95.886 108 20-Feb-98 26.500 75.500 -9.000 -9.000 -9.000 95.399 110 20-Feb-98 26.500 75.900 -9.000 -9.000 -9.000 96.398 110 20-Feb-98 26.500 75.900 -9.000 -9.000 -9.000 95.629 114 21-Feb-98 26.510 76.427 262.483 540.744 80.515 -9.000 114 21-Feb-98 26.510 76.428 262.273 539.635 80.446 -9.000 114 21-Feb-98 26.511 76.428 262.793 541.135 80.816 -9.000 114 21-Feb-98 26.514 76.431 262.827 538.937 79.301 -9.000 114 21-Feb-98 26.516 76.434 263.024 538.655 78.736 -9.000 114 21-Feb-98 26.508 76.482 262.900 538.355 79.284 -9.000 116 22-Feb-98 26.500 76.617 261.254 537.878 79.587 -9.000 117 22-Feb-98 26.500 76.683 260.123 536.113 78.455 -9.000 117 22-Feb-98 26.500 76.683 -9.000 -9.000 -9.000 96.873 117 22-Feb-98 26.500 76.683 -9.000 -9.000 -9.000 96.657 122 23-Feb-98 26.111 78.494 264.570 540.167 81.155 -9.000 122 23-Feb-98 26.111 78.494 264.310 539.409 80.459 -9.000 122 23-Feb-98 26.163 78.587 262.826 539.090 79.707 -9.000 122 23-Feb-98 26.168 78.606 262.319 538.885 79.498 -9.000 122 23-Feb-98 26.171 78.731 262.246 539.018 79.676 -9.000 122 23-Feb-98 27.001 79.200 -9.000 -9.000 -9.000 93.798 122 23-Feb-98 27.001 79.200 -9.000 -9.000 -9.000 93.073 122 23-Feb-98 27.001 79.200 -9.000 -9.000 -9.000 93.724 125 23-Feb-98 27.038 79.481 -9.000 -9.000 -9.000 97.231 125 23-Feb-98 27.038 79.481 -9.000 -9.000 -9.000 96.196 125 23-Feb-98 27.038 79.481 -9.000 -9.000 -9.000 95.753 130 24-Feb-98 26.999 79.937 -9.000 -9.000 -9.000 97.861 130 24-Feb-98 26.999 79.937 -9.000 -9.000 -9.000 97.393 NOAA Data Report ERL PMEL-68 CTD/O2 MEASUREMENTS COLLECTED ON A CLIMATE AND GLOBAL CHANGE CRUISE ALONG 24°N IN THE ATLANTIC OCEAN (WOCE Section A6) during January - February 1998 K.E. McTaggart -1* , G.C. Johnson -1* ,C.I.Fleurant -2* , and M.O. Baringer -3* -1* Pacific Marine Environmental Laboratory 7600 Sand Point Way NE Seattle, WA 98115 -2* University of Miami Cooperative Institute for Marine and Atmospheric Studies 4600 Rickenbacker Causeway Miami, FL 33149 -3* Atlantic Oceanographic and Meteorological Laboratory 4301 Rickenbacker Causeway Miami, FL 33149 May 1999 Contribution 2056 from NOAA/Pacific Marine Environmental Laboratory NOTICE Mention of a commercial company or product does not constitute an endorsement by NOAA/ER .Use of information from this publication concerning proprietary products or the tests of such products for publicity or advertising purposes is not authorized. CONTENTS 1. Introduction 2. Standards and Pre-Cruise Calibrations 2.1 Conductivity 2.2 Temperature 2.3 Pressure 2.4 Oxygen 3. Data Acquisition 3.1 Data Acquisition Problems 3.2 Salinity Analyses 4. At Sea Calibrations 5. Post-Cruise Calibrations 5.1 Conductivity 5.2 Temperature 5.3 Oxygen 6. Data Presentation 7. Participating Institutions/Personnel 8. Acknowledgments 9. References FIGURES* AND TABLES List of Figures* 1 CTD station locations made on the R/V Ronald H. Brown from January 24 to February 23, 1998 2 Pressures of bottle closures at each station 3 Calibrated CTD-bottle conductivity differences plotted against station number and pressure 4 Calibrated CTD-bottle oxygen differences plotted against station number and pressure 5 Potential temperature (°C)sections 6 Salinity (PSS-78) sections 7 Potential density (kg/m 3 )sections 8 CTD oxygen (µmol/kg) sections LIST OF TABLES 1 CTD cast summary 2a Shallow water column station groupings for CTD oxygen algorithm parameters 2b Deep water column station groupings for CTD oxygen algorithm parameters 3 Weather condition code used to describe each set of CTD measurements 4 Sea state code used to describe each set of CTD measurements 5 Visibility code used to describe each set of CTD measurements CTD DATA SUMMARY CTD/O2 measurements collected on a Climate and Global Change cruise along 24°N in the Atlantic Ocean (WOCE Section A6) during January-February 1998 K.E. McTaggart, G.C. Johnson,C.I. Fleurant, and M.O. Baringer ABSTRACT. Summaries of CTD/O2 measurements and hydrographic data acquired on a Climate and Global Change cruise during the winter of 1998 aboard the NOAA ship Ronald H. Brown are presented. The majority of these data were collected along 24.5°N from 23.5°W to 69°W. Completing the transatlantic section are data collected along a NE-SW dogleg off the coast of Africa, and along a second, short, zonal section along 26.5°N off the coast of Abaco Island from 69°W to 77°W, jogging north along 27°N in the Straits of Florida to 80°W. Data acquisition and processing systems are described and calibration procedures are documented. Station location, meteorological conditions, CTD/O2 summary data listings, profiles, and potential temperature-salinity diagrams are included for each cast. Section plots of oceanographic variables and hydrographic data listings are also given. 1. INTRODUCTION The NOAA Office of Global Programs (OGP) sponsors the Atlantic Climate Change Program (ACCP)and the Ocean-Atmosphere Carbon Exchange Study (OACES) as elements under the Climate and Global Change Program. The long-term objective of the Climate and Global Change Program is to provide reliable predictions of climate change and associated regional implications on time scales ranging from seasons to centuries. Large uncertainties in current predictions include the sources and sinks of greenhouse gases like carbon dioxide and the role of the ocean in mitigating or changing the timing of regional patterns associated with warmer climate. Hydrographic and direct velocity measurements collected during this cruise will help to quantify the water masses and determine the meridional overturning circulation responsible for the redistribution of heat, fresh water, and carbon in the center of the subtropical gyre and estimate the remineralization component of the CO2 increase in order to quantify the anthropogenic CO2 burden. The 24°N transatlantic section has been previously occupied in 1957, 1981, and 1992, revealing long-term variability in mid-depth temperature, salinity, and oxygen. This new data set extends this time series through a time when relatively large mid-depth changes due to decadal variations in the air-sea interaction for Labrador Sea Water formation have already been observed. In addition, this data set complements those from other seasons, allowing for investigation into seasonal variations in fluxes of mass, heat, and freshwater. CTD/O2 stations were occupied during leg 2. Stations were spaced roughly 55-85 km apart across the basin, closer near the coastlines. Full water column CTD/O2 profiles were collected at all stations and Lowered Acoustic Doppler Current Profiler (ADCP) measurements were taken on all but five stations prior to station 85. Underway salinity, temperature, shipboard ADCP, and carbon partial pressures were taken along the cruise track. Water samples were analyzed for a suite of natural and anthropogenic tracers including salinity, dissolved oxygen, inorganic nutrients, CFCs, dissolved inorganic carbon, total alkalinity, pH, pCO2 dissolved organic carbon, and carbon isotopes. Figure 1* shows station locations. Table 1 provides a summary of cast information. Leg 2 stations began with a NE-SW dogleg off the coast of Africa from station 1 at 28°N, 15°W in 130 m of water to station 22 at 24.5°N, 23.5°W in nearly 5000 m of water. Stations continued westward in a long zonal section along 24.5°N from station 22 to station 89 at 69°W across the Mid- Atlantic Ridge. The trackline jogged northwestward and stations were occupied along 26.5°N from 71°W at station 94 to 79°W at station 121. The remaining stations, 122-130, were along 27°N across the Straits of Florida. Leg 1 followed this same trackline in the opposite direction, deploying only XBTs to sample the temperature in the upper 750 m. 2. STANDARDS AND PRE-CRUISE CALIBRATIONS The CTD/O2 system is a real-time data acquisition system with the data from a Sea-Bird Electronics, Inc. (SBE) 9plus underwater unit transmitted via a conducting cable to a SBE 11plus deck unit. The serial data from the underwater unit is sent to the deck unit in RS-232 NRZ format. The deck unit decodes the serial data and sends it to a personal computer for display and storage in a disk file using Sea-Bird SEASOFT software. The SBE 911plus system transmits data from primary and auxiliary sensors in the form of binary number equivalents of the frequency or voltage outputs from those sensors. These are referred to as the raw data. The calculations required to convert raw data to engineering units are performed by software. The SBE 911plus system is electrically and mechanically compatible with standard unmodified rosette water samplers made by General Oceanics (GO), including the 1016 36-position sampler, which was used for all stations on this cruise. A modem and rosette interface allows the 911plus system to control the operation of the rosette directly without interrupting the flow of data from the CTD. The SBE 9plus underwater unit is configured with dual standard modular temperature (SBE 3) and conductivity (SBE 4) sensors which are mounted near the lower end cap. The conductivity cell entrance is co-planar with the tip of the temperature sensor probe. The pressure sensor is mounted inside the underwater unit main housing. A centrifugal pump module flushes water through sensor tubing at a constant rate independent of the CTD 's motion to improve dynamic performance. A dissolved oxygen sensor is added to the pumped sensor configuration following the temperature-conductivity (TC) pair. 2.1 CONDUCTIVITY The flow-through conductivity-sensing element is a glass tube (cell) with three platinum electrodes. The resistance measured between the center electrode and end electrode pair is determined by the cell geometry and the specific conductance of the fluid within the cell, and controls the out-put frequency of a Wien Bridge circuit. The sensor has a frequency out-put of approximately 3 to 12 kHz corresponding to conductivity from 0 to 7 Siemens/meter (0 to 70 mmho/cm). The SBE 4 has a typical accuracy/stability of ±0.0003 S/m/month and resolution of 0.00004 S/m at 24 samples per second. Pre-cruise sensor calibrations were performed at Sea-Bird Electronics, Inc. in Bellevue, Washington. The following coefficients were entered into SEASOFT using software module SEACON: s/n 1346 s/n 1347 December 6,1997 December 6,1997 g = -4.16857251e+00 g = -4.05527033e+00 h = 5.48731172e -01 h = 5.32990229e -01 i = 1.14301642e -04 i = 1.34295790e -05 j = 2.71673254e -05 j = 3.14203119e -05 ctcor = 3.2500e -06 ctcor = 3.2500e -06 cpcor = -9.5700e -08 cpcor = -9.5700e -08 Conductivity calibration certificates show an equation containing the appropriate pressure-dependent correction term to account for the effect of hydrostatic loading (pressure) on the conductivity cell: C (S /m)=(g + h f^2 + if^3 + j f^4 )/[10(1 + ctcor * t + cpcor * p)] where g ,h ,i ,j ,ctcor ,and cpcor are the calibration coefficients above, f is the instrument frequency (kHz), t is the water temperature (degrees Celsius), and is the water pressure (dbar). SEASOFT automatically implements this equation. 2.2 TEMPERATURE The temperature-sensing element is a glass-coated thermistor bead, pressure-protected by a stainless steel tube. The sensor output frequency ranges from approximately 5 to 13 kHz corresponding to temperature from -5 to 35°C. The output frequency is inversely proportional to the square root of the thermistor resistance which controls the output of a patented Wien Bridge circuit. The thermistor resistance is exponentially related to temperature. The SBE 3 thermometer has a typical accuracy/stability of ±0.004°C per year and resolution of 0.0003°C at 24 samples per second. The SBE 3 thermometer has a fast response time of 0.070 seconds. Pre-cruise sensor calibrations were performed at Sea-Bird Electronics, Inc. in Bellevue, Washington. The following coefficients were entered into SEASOFT using software module SEACON: s/n 1701 s/n 1075 December 4,1997 December 4,1997 g = 4.78998172e -03 g = 4.81195547e -03 h = 6.52982992e -04 h = 6.70417903e -04 i = 1.81051274e -05 i = 2.58445709e -05 j = 9.53750998e -07 j = 2.09728302e -06 f0 = 1000.0 f0 = 1000.0 Temperature (ITS-90)is computed according to T(C) = 1 /g +h [ln(f0 /f )] + i [ln^2 (f0 /f )] + j [ln^3 (f0 /f )] - 273.15 where g, h, i, j, and f0 are the calibration coefficients above and f is the instrument frequency (kHz). SEASOFT automatically implements this equation and converts between ITS-90 and IPTS-68 temperature scales as desired. 2.3 PRESSURE The Paroscientific series 4000 Digiquartz high pressure transducer uses a quartz crystal resonator whose frequency of oscillation varies with pressure induced stress measuring changes in pressure as small as 0.01 parts per million with an absolute range of 0 to 10,000 psia (0 to 6885 dbar). Repeatability, hysteresis, and pressure conformance are 0.005%FS. The nominal pressure frequency (0 to full scale) is 34 to 38 kHz. The nominal temperature frequency is 172 kHz +50 ppm/°C. Pre-cruise sensor calibrations were performed at Sea-Bird Electronics, Inc. in Bellevue, Washington. The following coefficients were entered into SEASOFT using software module SEACON: s/n 58808 August 9,1994 c1 = -4.583844e+04 c2 = -1.96344e -01 c3 = 1.27804e -02 d1 = 3.7796e -02 d2 = 0.0 t1 = 3.010293e+01 t2 = -2.93260e -04 t3 = 3.61082e -06 t4 = 3.74863e -09 Pressure coefficients are first formulated into c = c 1 + c 2 * U + c 3 * U^2 d = d 1 + d 2 * U t0 = t 1+t 2 * U + t 3 * U^2 + t 4 * U^3 where U is temperature in degrees Celsius. Then pressure is computed according to P (psia ) = c *[1 - (t 0^2 /t^2 )] * {1 - d [1 - (t 0^2 /t^2 )]} where t is pressure period (µs). SEASOFT automatically implements this equation. 2.4 OXYGEN The SBE 13 dissolved oxygen sensor uses a Beckman polarographic element. Oxygen sensors determine the dissolved oxygen concentration by counting the number of oxygen molecules per second (flux) that diffuse through a membrane. By knowing the flux of oxygen and the geometry of the diffusion path the concentration of oxygen can be computed. The permeability of the membrane to oxygen is a function of temperature and ambient pressure. The interface electronics outputs voltages proportional to membrane current (oxygen current)and membrane temperature (oxygen temperature). Oxygen temperature is used for internal temperature compensation. Initial computation of dissolved oxygen in engineering units is done in the software. The range for dissolved oxygen is 0 to 650 µmol/kg; nominal accuracy is 4 µmol/kg; resolution is 0.4 µmol/kg. Response times are roughly 2 s at 25°C and 5 s at 0°C. The following oxygen calibrations were entered into SEASOFT using SEACON: s/n 130364 s/n 130353 s/n 130381 December 10,1997 December 11,1997 December 12,1997 m = 2.4614e -07 m = 2.4624e -07 m = 2.4496e -07 b = -5.0212e -10 b = -5.6634e -10 b = -2.7680e -10 soc = 3.4185 soc = 3.2070 soc = 3.2309 boc = -0.0210 boc = -0.0290 boc = -0.0260 tcor = -3.3e -02 tcor = -3.3e -02 tcor = -3.3e-02 pcor = 1.5e -04 pcor = 1.5e -04 pcor = 1.5e -04 tau = 2.0 tau = 2.0 tau = 2.0 wt = 0.67 wt = 0.67 wt = 0.67 k = 9.0037 k = 8.9643 k = 9.0214 c = -6.8110 c = -6.8963 c = -6.7355 The use of these constants in linear equations of the form I = mV + b and T = kV + c will yield sensor membrane current and temperature (with a maximum error of about 0.5°C) as a function of sensor output voltage. 3. DATA ACQUISITION CTD/O2 measurements were made using a SBE 9plus CTD with dual sensor configuration. Each set of sensors included a temperature, conductivity, and dissolved oxygen sensor. The sets were placed as mirror images to each other mounted low on the CTD main housing with the intakes approximately 6-8 inches apart. The TC pairs were monitored for calibration drift and shifts by examining the differences between the two pairs on each CTD and comparing CTD salinities with bottle salinity measurements. AOML's SBE 9plus CTD/O2 s/n 09P10779-0363 (sampling rate 24 Hz) was mounted in a 36-position frame and employed as the primary package. Auxiliary sensors included an LADCP and Benthos altimeter. Water samples were collected using a GO 36-bottle rosette and 10-liter Nisken bottles. The primary package was used for all casts during this cruise. The package entered the water from the starboard side of the ship and was held within 10 m of the surface for 1 minute in order to activate the pump. The package was lowered at a rate of 30 m/min to 50 m, 45 m/min to 200 m, and 60 m/min generally to within 10 m of the bottom, slowing gradually on the approach. The position of the package relative to the bottom was monitored by the ship 's Precision Depth Recorder (PDR)and the altimeter. A bottom depth was estimated from bathymetric charts and the PDR ran during the bottom 1000 m of the cast. Figure 2* shows the pressures of bottle closures during the upcast. Upon completion of the cast, sensors were flushed repeatedly and stored with a dilute Triton-X solution in the plumbing. Nisken bottles were then sampled for various water properties detailed in the introduction. Sample protocols conformed to those specified by the WOCE Hydrographic Programme. A SBE 11plus deck unit received the data signal from the CTD. The analog data stream was recorded onto video cassette tape as a backup. Digitized data were forwarded to a personal computer equipped with SEASOFT acquisition and processing software version 4.230. Preliminary temperature, salinity, and oxygen profiles were displayed in real time. Raw data files were archived to Syquest tapes. 3.1 DATA ACQUISITION PROBLEMS All of the three oxygen sensors employed during this cruise were problematic owing to the age of the modules. Oxygen sensor s/n 364 associated with the primary TC pair was replaced with oxygen sensor s/n 381 prior to station 33. S/n 364 had drifted more than 15 µmol/kg from its calibration and was exhibiting numerous shifts in oxygen current throughout the water column. Redundant oxygen sensor s/n 353 associated with the secondary TC pair was removed prior to station 45 in an effort to conserve its usefulness in case primary oxygen sensor s/n 381 failed later in the cruise. Also, secondary sensor s/n 353 was exhibiting multiple shifts in oxygen current at varying depths and thought to be more difficult to calibrate. Primary sensor s/n 381 was better behaved although much noisier. There was no primary oxygen data from sensor s/n 381 collected for station 34 owing to a poor connection of the dissolved oxygen module. 3.2 SALINITY ANALYSES Bottle salinity analyses were performed in the ship's temperature- controlled salinity laboratory using two Guildline Model 8400B inductive autosalinometers, and a dedicated personal computer. Software allowed the user to standardize the autosal, and perform a second standardization using a fresher standard (30 PSS) for a linearity check. IAPSO Standard Seawater batch #133 was used as the primary standard. IAPSO Standard Seawater batch #305 was used as the second, fresher standard. The autosalinometer in use was standardized before each cast of samples were analyzed, or every 36 samples. The software limits set required that each successive reading be within ±0.002 PSS or the program would reject that reading and seek another. Stable room temperature and high performance of the autosalinometers allowed these limits to be so strictly set. Duplicate samples usually taken from the deepest bottle on each cast were analyzed on a subsequent day. Bottle salinities were compared with preliminary CTD salinities to aid in the identification of leaking bottles as well as to monitor the CTD conductivity cells' performance and drift. The expected precision of the autosalinometer with an accomplished operator is 0.001 PSS, with an accuracy of 0.003. The standard deviation of the duplicate differences is 0.0003 PSS. This value is far below the expected precision. Calibrated CTD salinities replace missing bottle salinities in the hydrographic data listing and are indicated by an asterisk. 4. AT SEA PROCESSING SEASOFT consists of modular menu driven routines for acquisition, display, processing, and archiving of oceanographic data acquired with SBE equipment and is designed to work with an IBM or compatible personal computer. Raw data are acquired from the instruments and are stored unmodified. The conversion module DATCNV uses the instrument configuration and pre-cruise calibration coefficients to create a converted engineering unit data file that is operated on by all SEASOFT post processing modules. The following is the SEASOFT processing module sequence and specifications used in the reduction of CTD/O2 data from this cruise: o DATCNV converted the raw data to pressure, temperature, conductivity, oxygen current, and oxygen temperature; and computed salinity, the time rate of change of oxygen current, and preliminary oxygen. DATCNV also extracted bottle information where scans were marked with the bottle confirm bit during acquisition. o ROSSUM created a summary of the bottle data. Bottle position, date, and time were automatically output. Pressure, temperature, conductivity, salinity, oxygen current, oxygen temperature, time rate of change of oxygen current, and preliminary oxygen values were averaged over a 2-s interval (48 scans) from 5 to 3 s prior to the confirm bit in order to avoid spikes in conductivity and oxygen current owing to minor incompatibilities between the SBE 911plus CTD/O2 system and GO 1016 rosette. ROSSUM computed potential temperature and sigma-theta. o WILDEDIT marked extreme outliers in the data files. The first pass of WILDEDIT obtained an accurate estimate of the true standard deviation of the data. The data were read in blocks of 200 scans. Data greater than two standard deviations were flagged. The second pass computed a standard deviation over the same 200 scans excluding the flagged values. Values greater than 16 standard deviations were marked bad. o SPLIT removed decreasing pressure records from the data files leaving only the downcast. o FILTER performed a low pass filter on pressure with a time constant of 0.15 s. In order to produce zero phase (no time shift) the filter first runs forward through the file and then runs backward through the file. o Measurements can be misaligned due to the inherent time delay of the sensor response, the water transit time delay in the pumped plumbing line, and the sensors being physically misaligned in depth. ALIGNCTD aligns conductivity, temperature, and oxygen in time relative to pressure to ensure that all calculations were made using measurements from the same parcel of water minimizing salinity spiking and density errors. Primary conductivity was not advanced in ALIGNCTD because it is done in the factory setting of the 11plus deck unit. Secondary conductivity, however, is not advanced in the deck unit and so was advanced 0.073 s in ALIGNCTD. Because SBE 3 temperature sensor response is fast (0.06 s), it was not necessary to advance temperature relative to pressure. Oxygen sensors s/n 364 and s/n 353 were advanced 3.0 s in ALIGNCTD; s/n 381 was not advanced in the software. o CELLTM used a recursive filter to remove conductivity cell thermal mass effects from measured conductivity. Both conductivity cells were epoxy coated and therefore the thermal anomaly amplitude (alpha) and the time constant (1/beta) were 0.03 and 9.0 respectively for each sensor. o DERIVE was used to recompute doxc/dt and oxygen with a time window size of 2.0 seconds. o LOOPEDIT marked scans where the CTD was moving less than a minimum velocity of 0.25 m/s or travelling backwards due to ship roll. o BINAVG averaged the data into 1-dbar pressure bins starting at 1 dbar with no surface bin. The center value of the first bin was set equal to the bin size. The bin minimum and maximum values are the center value ± half the bin size. Scans with pressures greater than the minimum and less than or equal to the maximum were averaged. Scans were interpolated so that a data record exists every decibar. The number of points averaged in each bin was added to the variables listed in the data file. o DERIVE recomputed salinity. o STRIP removed scan number; and salinity, time rate of change of oxygen current, and preliminary oxygen computed in DATCNV from the data files. o TRANS converted the data file format from binary to ASCII format. o In addition to the Seasoft processing modules, several PMEL programs were used to further reduce the CTD/O2 data: o Because the pump does not turn on until 60 seconds after the CTD package is in the water, measurements of near-surface conductivity and oxygen values are inaccurate. FILLSFC was used to copy the first good value of salinity, potential temperature, oxygen, and oxygen current back to the surface. FILLSFC then back-calculated temperature and conductivity, and zeroed the time rate of change of oxygen current for those records. Filled salinities ranged from 3 to 9dbar,usually 5 dbar. There were only 7 stations where surface potential temperatures had to be filled in 1-2 dbar. Filled oxygens also ranged from 3 to 9 dbar, usually 5 dbar. WOCE flags for the affected parameters were changed to "7 " for extrapolation. o DESPIKE1 removed spikes from primary oxygen current and primary oxygen temperature data.DESPIKE1 also removed spikes from primary salinity data. Data were linearly interpolated over despiked records and the associated WOCE flags were changed to "6 "for interpolation. Conductivity was back-calculated, and potential temperature and sigma- theta were recomputed for the interpolated records. o DESPIKE2 removed spikes from secondary data in the same fashion as DESPIKE1. o Package slowdowns and reversals owing to ship roll can move mixed water in tow to in front of the CTD sensors and create artificial density inversions and other artifacts. In addition to SEASOFT module LOOPEDIT, PMEL program DELOOP computed values of density locally referenced between every 1 dbar of pressure to compute N^2 = (-g/rho)(d-rho/dz) and linearly interpolated measured parameters over those records where N^2 less than or equal to - 1.0e -05 s^-2. WOCE flags were changed to "6" for interpolation and derived variables were recomputed over interpolated intervals. o FILTDOC applied a median filter of width 5 dbar to the time rate of change in oxygen current. o FIX353 added a positive shift to secondary oxygen current (s/n 353) at user selected depths, usually deeper than 3500 dbar, and recomputed oxygen. This shift was applied to stations 16-44 to correct an odd but persistent behavior of the aged oxygen module. o FIX381 added a negative shift to primary oxygen current (s/n 381) at user selected depths, usually around 2900 dbar, and recomputed oxygen. This shift was applied to stations 50-118 to correct an odd but persistent behavior of the aged oxygen module. 5. POST-CRUISE CALIBRATIONS Post-cruise sensor calibrations were done at Sea-Bird Electronics, Inc. during March and May 1998.Secondary sensor pair T1075 and C1347 were selected for final data reduction for all stations for two reasons based on post-cruise temperature calibration information. First, T1075 has a drift of 0.3e -03°C/year with an uncertainty of 0.3e -03°C based on five calibrations between August 1996 and May 1998, whereas T1701 has a drift of 1.5e-03°C/year with an uncertainty of -0.4e -03°C based on seven calibrations between May 1996 and May 1998.Second,T1075 was determined by Sea-Bird to have no pressure correction, whereas T1701 has a pressure correction of -1.4e-03°C/5000 dbar. Secondary oxygen data from sensor s/n 353 was retained for stations 1-32 and 34; primary oxygen data from sensor s/n 381 was retained for stations 33 and 35-130. Post-cruise calibrations were applied to CTD data associated with bottle data using PMEL program CALBOT. WOCE quality flags were appended to bottle data records using PMEL program FLAG. Quality flags were determined by plotting the absolute value of sample residuals versus pressure and selecting a cutoff value for bad flags. The value of 2.8 standard deviations of the remaining residuals was the cutoff for questionable flags. Of the 4313 sample salinities, 0.4% were flagged as bad and 3.6% were flagged as questionable. Of the 4130 sample oxygens, 1.2% were flagged as bad and 4.9% were flagged as questionable. 5.1 CONDUCTIVITY Conductivity slope and bias, along with a linear pressure term (modified beta), were computed by a least-squares minimization of CTD and bottle conductivity differences. The function minimized was BC - m * CC - b - beta * CP where BC is bottle conductivity (S/m), CC is pre-cruise calibrated CTD conductivity (S/m), CP is the CTD pressure (dbar), m is the conductivity slope, b is the bias (S/m), and beta is a linear pressure term (S/m/dbar). The final CTD conductivity (S/m) is m * CC + b + beta * CP The slope term m is a fourth-order polynomial function of station number to allow the entire cruise to be fit at once with a smoothly-varying station-dependent slope correction. For sensor C1347 a series of fits were made, each fit throwing out bottle values for locations having a residual between CTD and bottle conductivity greater than three standard deviations. This procedure was repeated with the remaining bottle values until no more bottle values were thrown out. For C1347, the slope correction ranged from 0.99993647 to 0.99998722, the bias applied was -1.3e-04 S/m, and the beta term was -1.41e -08 S/m/ dbar. Of 4313 bottles, the percentage of bottles retained in the fit was 75.65 with a standard deviation of 1.144e -04 S/m. PMEL program CALCTD applied these calibrations. CTD-bottle conductivity differences are plotted against station number to show the stability of the calibrated CTD conductivities relative to the bottle conductivities (Fig.3*, upper panel). CTD-bottle conductivity differences are plotted against pressure to show the tight fit below 500 m and the increasing scatter above 500 m (Fig.3*, lower panel). 5.2 TEMPERATURE The pre-cruise calibration of T1075 is the mean of the two post-cruise calibrations, and is within 0.05e -03°C of the overall drift trajectory over the duration of the cruise as determined by the calibration history of the sensor. Therefore, the pre-cruise calibration was used in the final processing. The pressure correction for this sensor was determined by Sea-Bird to be zero. However, a bias of -0.6e -03°C was applied to temperature data in program CALCTD to account for the effect of viscous heating on SBE 3 sensors. An adjustment of -0.6e -03°C results in errors of no more than ± 0.15e -03°C from this effect for the full range of oceanographic temperature and salinity. 5.3 Oxygen In situ oxygen samples collected during CTD/O2 profiles are used for post- measurement calibration. Because the dissolved oxygen sensor has an obvious hysteresis, PMEL program OXDWNP replaced up-profile water sample data with corresponding processed (see section 4) down-profile CTD/O2 data at common pressure levels. Oxygen saturation values were computed according to Benson and Krausse (1984) in units of µmol/kg. The algorithm used for converting oxygen sensor current and probe temperature measurements to oxygen as described by Owens and Millard (1985) requires a non-linear least squares regression technique in order to determine the best-fit coefficients of the model for oxygen sensor behavior to the water sample observations. WHOI program OXFITMR uses Numerical Recipes (Press et al.,1986) Fortran routines MRQMIN, MRQCOF, GAUSSJ, and COVSRT to perform non-linear least squares regression using the Levenberg-Marquardt method. A Fortran subroutine FOXY describes the oxygen model with the derivatives of the model with respect to six coefficients in the following order: oxygen current slope, temperature correction, pressure correction, weight, oxygen current bias, and oxygen current lag. Program OXFITMR reads the data for a group of stations. The data are edited to remove spurious points where values are less than zero or greater than 1.2 times the saturation value. The routine varies the six (or fewer) parameters of the model in such a way as to produce the minimum sum of squares in the difference between the calibration oxygens and the computed values. Individual differences between the calibration oxygens and the computed oxygen values (residuals) are then compared with the standard deviation of the residuals. Any residual exceeding an edit factor of 2.8 standard deviations is rejected. A factor of 2.8 will have a 0.5% chance of rejecting a valid oxygen value for a normally distributed set of residuals. The iterative fitting process is continued until none of the data fail the edit criteria. The best fit to the oxygen probe model coefficients is then determined. Coefficients were applied using program CA 381 or CA 353 for plotting in Matlab. By plotting the oxygen residuals versus station, appropriate station groupings for further refinements of fitting are obtained by looking for abrupt station-to-station changes in the residuals. For each grouping, two sets of coefficients were determined, one fitting bottles less than or equal to 2500 dbar and a second fitting bottles greater than or equal to 2000 dbar. Pressure correction, weight, and lag coefficients were fixed within a reasonable range (noted by asterisks in Table 2) from output of full water column group fits. The two sets of coefficients were blended at 2250 dbar using a pair of hyperbolic tangent functions with 250-dbar decay scales. Final coefficients were applied to downcast data using PMEL program CA C381 and CALC3532. Calibrated oxygens were extracted from the calibrated profiles by pressure to create the final bottle file using CALBOT. CTD-bottle oxygen differences are plotted against station number to show the stability of the calibrated CTD oxygens relative to the bottle oxygens (Fig.4*, upper panel). Note that the residuals (Table 2 and Fig.4*) are near the nominal WOCE standard accuracy of 0.5% for discrete oxygen titrations. CTD-bottle oxygen differences are plotted against pressure to show the tight fit below 1200 m and the increasing scatter above 1200 m (Fig.4*, lower panel). 6. DATA PRESENTATION PMEL program 24N EPIC converted finalized CTD/O2 data files into EPIC format (Soreide et al.,1995); and computed ITS-90 temperature, ITS-90 potential temperature, and dynamic height. EPIC data files contain a WOCE quality flag parameter associated with pressure, temperature, CTD salinity, and CTD oxygen. Quality flag definitions can be found in the WOCE Operations Manual (1994). The final calibrated data in EPIC format were used to produce the plots and listings that follow. The majority of the plots were produced using Plot Plus Scientific Graphics System (Denbo, 1992). Vertical sections of potential temperature, CTD salinity, potential density, and CTD oxygen are contoured with pressure as the vertical axis and latitude as the horizontal axis (Figs.5* - 8*). Nominal vertical exaggerations are 1000:1 below 1000 dbar (lower panels) and 2500:1 above 1000 dbar (upper panels). Plots and summary listings of the CTD/O2 data follow for each cast. Hydrographic bottle data at discrete depths are listed in the final section. The hydrographic listings presented include two-digit WOCE quality flags. The numeric digits are associated with bottle salinity and bottle oxygen. Quality flag definitions can be found in the WOCE Operations Manual (1994). 7. PARTICIPATING INSTITUTIONS/PERSONNEL see "LIST OF PARTICIPANTS" NOAA DATA REPORT 0AR AOML-41, above. 8. ACKNOWLEDGMENTS The assistance of the officers, crew, and survey technician Jonathan Shannahoff of the NOAA ship Ronald H. Brown is gratefully acknowledged. Gregg Thomas provided very high quality sample salinities and analysis documentation. This cruise was sponsored by NOAA 's Office of Global Programs. 9. REFERENCES Benson, B.B., and D. Krausse Jr. (1984): The concentration and isotopic fractionation of oxygen dissolved in freshwater and seawater in equilibrium with the atmosphere. Limnol. Oceanogr., 29, 620 -632. Denbo, D.W. (1992): PPLUS Graphics, P.O. Box 4, Sequim, WA, 98382. Owens, W.B., and R.C. Millard Jr. (1985): A new algorithm for CTD oxygen calibration. J. Phys. Oceanogr., 15, 621 -631. Press, W., B. Flannery, S. Teukolsky, and W. Vetterling (1986): Numerical Recipes: The Art of Scientific Computing. Cambridge University Press, 818 pp. Seasoft CTD Aquisition Software Manual (1994): Sea-Bird Electronics, Inc., 1808 136th Place NE, Bellevue, Washington, 98005. Soreide, N.N. ,M.L. Schall, W.H. Zhu, D.W. Denbo, and D.C. McClurg (1995): EPIC: An oceanographic data management, display and analysis system. Proceedings,11th International Conference on Interactive Information and Processing Systems for Meteorology, Oceanography, and Hydrology, January 15 -20, 1995, Dallas, TX, 316 -321. WOCE Operations Manual (1994): Volume 3: The Observational Programme, Section 3.1: WOCE Hydrographic Programme, Part 3.1.2: Requirements for WHP Data Reporting. WHP Office Report 90-1, WOCE Report No. 67/91, Woods Hole, MA, 02543. FIGURES* AND TABLES Figure 1*: CTD station locations made on the R/V Ronald H. Brown from January 24 to February 23, 1998. TABLE 1: CTD cast summary. Station Latitude Longitude Date Time Depth Cast (m) (db) 1 27°55.0'N 13°22.2'W 24 JAN 98 0040 132 125 2 27°54.0'N 13°24.1'W 24 JAN 98 0211 509 516 3 27°52.9'N 13°25.0'W 24 JAN 98 0425 678 655 4 27°51.0'N 13°33.0'W 24 JAN 98 0638 1086 1082 5 27°49.8'N 13°48.7'W 24 JAN 98 0926 1518 1508 6 27°37.3'N 14°13.4'W 24 JAN 98 1309 2037 7 27°26.0'N 14°51.0'W 24 JAN 98 1759 2589 2609 8 27°14.0'N 15°35.2'W 24 JAN 98 2329 3133 3175 9 27° 2.0'N 16° 6.9'W 25 JAN 98 0432 3488 3525 10 26°50.0'N 16°40.0'W 25 JAN 98 0936 3622 3661 11 26°40.0'N 17°11.9'W 25 JAN 98 1440 3660 3705 12 26°31.0'N 17°52.0'W 25 JAN 98 2003 3662 3704 13 26°20.9'N 18°20.0'W 26 JAN 98 0049 3559 3598 14 26°10.0'N 18°49.0'W 26 JAN 98 0558 3495 3533 15 25°59.0'N 19°21.9'W 26 JAN 98 1051 3731 3765 16 25°48.0'N 19°54.0'W 26 JAN 98 1623 4018 4066 17 25°37.0'N 20°26.0'W 26 JAN 98 2156 4303 4364 18 25°25.6'N 20°56.8'W 27 JAN 98 0330 4468 4529 19 25°15.0'N 21°29.0'W 27 JAN 98 0920 4580 4648 20 25° 3.6'N 22° 1.6'W 27 JAN 98 1533 4742 4812 21 24°47.0'N 22°48.0'W 27 JAN 98 2259 4889 4972 22 24°30.0'N 23°29.0'W 28 JAN 98 0549 5017 5091 23 24°29.9'N 24°13.0'W 28 JAN 98 1235 5144 5223 24 24°30.0'N 24°57.0'W 28 JAN 98 1903 5255 5332 25 24°30.0'N 25°41.0'W 29 JAN 98 0145 5330 5411 26 24°30.0'N 26°25.0'W 29 JAN 98 0858 5413 5499 27 24°30.0'N 27° 9.0'W 29 JAN 98 1558 5534 5629 28 24°30.0'N 27°53.0'W 29 JAN 98 2300 5411 5514 29 24°30.0'N 28°37.0'W 30 JAN 98 0559 5670 5760 30 24°30.0'N 29°26.0'W 30 JAN 98 1317 5524 5646 31 24°30.0'N 30°16.0'W 30 JAN 98 2034 5650 5718 32 24°30.0'N 31° 5.0'W 31 JAN 98 0400 6027 6109 33 24°30.0'N 31°55.0'W 31 JAN 98 1149 5998 6048 34 24°30.0'N 32°44.0'W 31 JAN 98 1921 6233 6277 35 24°29.9'N 33°34.0'W 01 FEB 98 0325 6237 6362 36 24°30.1'N 34°23.0'W 01 FEB 98 1116 5142 5234 37 24°30.0'N 35°13.0'W 01 FEB 98 1859 5150 5245 38 24°30.0'N 36° 2.0'W 02 FEB 98 0207 5639 5770 39 24°30.0'N 36°52.0'W 02 FEB 98 0933 5181 5406 40 24°30.0'N 37°41.0'W 02 FEB 98 1650 5499 5558 41 24°30.0'N 38°30.8'W 03 FEB 98 0001 4862 4864 42 24°30.0'N 39°14.9'W 03 FEB 98 0636 5191 5262 43 24°30.0'N 39°59.0'W 03 FEB 98 1323 5105 5173 44 24°30.0'N 40°32.0'W 03 FEB 98 1912 5087 4878 45 24°30.0'N 41° 5.0'W 04 FEB 98 0118 5167 5241 46 24°30.0'N 41°38.0'W 04 FEB 98 0707 4721 4780 47 24°30.0'N 42°11.0'W 04 FEB 98 1254 3829 4039 48 24°30.0'N 42°44.0'W 04 FEB 98 1833 3716 3516 49 24°30.0'N 43°17.0'W 04 FEB 98 2355 3716 3763 50 24°30.0'N 43°50.0'W 05 FEB 98 0528 3759 3800 51 24°30.0'N 44°23.0'W 05 FEB 98 1045 3977 4013 52 24°30.0'N 44°56.0'W 05 FEB 98 1604 3591 3636 53 24°30.0'N 45°29.0'W 05 FEB 98 2101 3109 3346 54 24°30.0'N 46° 2.0'W 06 FEB 98 0152 2724 2765 55 24°30.0'N 46°35.1'W 06 FEB 98 0640 3520 3213 56 24°30.0'N 47° 8.0'W 06 FEB 98 1137 3619 3628 57 24°30.0'N 47°41.0'W 06 FEB 98 1653 3954 4118 58 24°30.0'N 48°14.0'W 06 FEB 98 2234 3988 3976 59 24°30.0'N 48°46.9'W 07 FEB 98 0529 4343 4313 60 24°30.0'N 49°20.0'W 07 FEB 98 1230 5273 5353 61 24°30.0'N 49°53.0'W 07 FEB 98 1953 4532 4634 62 24°30.0'N 50°26.0'W 08 FEB 98 0257 4762 4823 63 24°30.0'N 50°59.0'W 08 FEB 98 1026 5296 5437 64 24°30.0'N 51°32.0'W 08 FEB 98 1721 5284 5366 65 24°30.0'N 52° 9.0'W 09 FEB 98 0012 8094 5310 66 24°30.0'N 52°38.8'W 09 FEB 98 0651 5281 5369 67 24°30.0'N 53°11.0'W 09 FEB 98 1324 5527 5605 68 24°30.0'N 53°44.0'W 09 FEB 98 1957 6016 6077 69 24°30.0'N 54°28.0'W 10 FEB 98 0330 5657 5245 70 24°29.9'N 55°12.0'W 10 FEB 98 1127 5917 6010 71 24°30.0'N 55°56.0'W 10 FEB 98 1937 6463 6500 72 24°30.0'N 56°40.0'W 11 FEB 98 0308 6012 6129 73 24°30.0'N 57°24.0'W 11 FEB 98 1038 6313 6394 74 24°30.0'N 58° 8.0'W 11 FEB 98 1803 5835 5933 75 24°30.0'N 58°52.0'W 12 FEB 98 0125 5920 6017 76 24°30.0'N 59°36.0'W 12 FEB 98 0857 5813 5912 77 24°30.0'N 60°20.0'W 12 FEB 98 1622 5845 5961 78 24°30.0'N 61° 4.0'W 12 FEB 98 2328 5866 5971 79 24°30.0'N 61°48.0'W 13 FEB 98 0642 5891 80 24°30.0'N 62°32.0'W 13 FEB 98 1345 5866 5970 81 24°29.9'N 63°15.9'W 13 FEB 98 2051 5843 5913 82 24°30.0'N 64° 0.0'W 14 FEB 98 0403 5834 5862 83 24°30.0'N 64°48.0'W 14 FEB 98 1117 5688 5839 84 24°30.1'N 65°28.1'W 14 FEB 98 1817 5548 5651 85 24°30.0'N 66°12.0'W 15 FEB 98 0128 5332 5429 86 24°30.0'N 66°56.0'W 15 FEB 98 0856 5730 5817 87 24°30.0'N 67°40.0'W 15 FEB 98 1603 5741 5804 88 24°30.0'N 68°24.0'W 15 FEB 98 2303 5712 89 24°30.0'N 69° 8.0'W 16 FEB 98 0609 5651 5816 90 25° 1.0'N 69°30.1'W 16 FEB 98 1316 5620 5736 91 25°23.0'N 69°52.0'W 16 FEB 98 1932 5547 5709 92 25°45.5'N 70°14.1'W 17 FEB 98 0142 5515 5620 93 26° 8.4'N 70°36.9'W 17 FEB 98 0806 5506 5606 94 26°30.0'N 71° 0.0'W 17 FEB 98 1423 5491 5596 95 26°30.0'N 71°21.0'W 17 FEB 98 1945 5488 5580 96 26°30.0'N 71°44.0'W 18 FEB 98 0111 5389 5466 97 26°30.0'N 72° 6.0'W 18 FEB 98 0635 5281 5354 98 26°30.0'N 72°28.0'W 18 FEB 98 1150 5159 5263 99 26°30.0'N 72°51.0'W 18 FEB 98 1701 5136 5216 100 26°30.0'N 73°13.0'W 18 FEB 98 2225 5065 5147 101 26°30.0'N 73°35.0'W 19 FEB 98 0340 4932 5007 102 26°29.5'N 73°58.0'W 19 FEB 98 0848 4665 4714 103 26°30.0'N 74°15.0'W 19 FEB 98 1326 4553 4606 104 26°30.0'N 74°31.0'W 19 FEB 98 1742 4559 4563 105 26°30.0'N 74°48.0'W 19 FEB 98 2203 4538 4603 106 26°30.0'N 75° 5.0'W 20 FEB 98 0233 4629 4677 107 26°30.0'N 75°18.0'W 20 FEB 98 0732 4638 4706 108 26°30.0'N 75°30.0'W 20 FEB 98 1149 4688 4751 109 26°30.0'N 75°42.0'W 20 FEB 98 1620 4694 4764 110 26°30.0'N 75°54.0'W 20 FEB 98 2034 4747 4818 111 26°30.0'N 76° 5.0'W 21 FEB 98 0111 4802 4875 112 26°30.0'N 76°12.0'W 21 FEB 98 0521 4819 4889 113 26°30.0'N 76°18.0'W 21 FEB 98 0951 4834 4909 114 26°30.3'N 76°25.3'W 21 FEB 98 1430 4848 4911 115 26°30.0'N 76°31.0'W 21 FEB 98 1911 4848 4919 116 26°30.0'N 76°37.0'W 21 FEB 98 2311 4736 4806 117 26°30.0'N 76°41.0'W 22 FEB 98 0332 4491 4659 118 26°30.0'N 76°45.2'W 22 FEB 98 0803 3815 3912 119 26°30.0'N 76°47.0'W 22 FEB 98 1149 3241 2325 120 26°30.0'N 76°49.0'W 22 FEB 98 1435 1390 1386 121 26°31.2'N 76°54.0'W 22 FEB 98 1714 719 409 122 27° 0.0'N 79°12.0'W 23 FEB 98 0917 477 472 123 27° 0.1'N 79°17.0'W 23 FEB 98 1058 613 611 124 27° 0.1'N 79°22.0'W 23 FEB 98 1245 687 670 125 27° 2.3'N 79°28.9'W 23 FEB 98 1517 766 740 126 27° 0.8'N 79°36.4'W 23 FEB 98 1720 667 667 127 27° 1.2'N 79°40.5'W 23 FEB 98 1906 547 532 128 27° 0.1'N 79°47.3'W 23 FEB 98 2041 384 375 129 27° 0.4'N 79°51.4'W 23 FEB 98 2153 279 270 130 26°59.9'N 79°56.2'W 23 FEB 98 2303 140 130 FIGURE 2*: Pressures of bottle closures at each station. FIGURE 3*: Calibrated CTD-bottle conductivity differences plotted against station number (upper panel). Calibrated CTD-bottle conductivity differences plotted against pressure (lower panel). TABLE 2a: Shallow water column station groupings for CTD oxygen algorithm parameters. Station Sensor StdDev #Obs 2.8*sd 1:Bias 2:Slope 3:Pcor 4:Tcor 5:Wt 6:Lag 1-9 353 0.204 174 0.571 -0.047 0.004728 0.0001642* -0.02965 0.9699* -0.2047* 10-24 353 2.686 373 7.521 -0.038 0.004621 0.0001642* -0.02953 0.9699* -0.2047* 25-32 353 3.232 203 9.050 -0.045 0.004640 0.0001642* -0.02960 0.9699* -0.2047* 33-44 353 3.110 268 8.708 -0.043 0.004635 0.0001642* -0.02791 0.9699* -0.2047* 33-35 381 2.076 46 5.813 -0.021 0.004515 0.0001561* -0.03058 0.7771* 6.927* 36-38 381 2.426 76 6.793 -0.006 0.004751 0.0001451* -0.03077 0.4608* 6.111* 40-43 381 2.262 96 6.334 -0.013 0.004791 0.0001536* -0.03068 0.7629* 2.239* 44-46 381 1.704 74 4.771 -0.030 0.004905 0.0001588* -0.03109 0.7355* 2.040* 47-50 381 3.089 105 8.649 -0.039 0.005125 0.0001538* -0.03278 0.7243* 5.715* 51-56 381 1.494 177 4.183 -0.018 0.004911 0.0001559* -0.03079 0.7322* 4.255* 57-59 381 2.124 81 5.947 -0.014 0.004895 0.0001556* -0.03024 0.7769* 3.391* 60-66 381 1.645 174 4.606 -0.014 0.004978 0.0001520* -0.03077 0.7619* 5.183* 67-69 381 2.013 71 5.636 0.003 0.004889 0.0001501* -0.03031 0.7214* 5.801* 70-76 381 1.885 176 5.278 -0.006 0.004983 0.0001498* -0.03057 0.7582* 3.632* 77-81 381 2.410 125 6.748 -0.018 0.005023 0.0001539* -0.03074 0.6860* 6.501* 82-90 381 2.222 222 6.222 -0.011 0.005050 0.0001509* -0.03086 0.7111* 4.469* 91 381 1.834 23 5.135 -0.091 0.005123 0.0001774* -0.03194 0.7987* 4.997* 92-95 381 2.118 100 5.930 -0.101 0.005101 0.0001780* -0.03265 0.8516* 8.153* 96-97 381 2.718 52 7.610 -0.103 0.005221 0.0001758* -0.03319 0.8620* 2.643* 98-99 381 2.177 52 6.096 -0.070 0.005188 0.0001626* -0.03241 0.8482* 10.850* 100-104 381 1.653 127 4.628 -0.035 0.005013 0.0001575* -0.03155 0.8902* 9.426* 105-109 381 1.847 127 5.172 0.001 0.004887 0.0001472* -0.03111 0.9373* 5.558* 110-119 381 2.159 237 6.045 -0.035 0.005059 0.0001587* -0.03222 0.8042* 6.654* 120-130 381 3.152 195 8.826 0.031 0.004859 0.0001209* -0.03049 0.9413* 4.374* * Fixed parameter from full water column fit of all bottles (sensor 353) or each grouping (sensor 381). TABLE 2b: Deep water column station groupings for CTD oxygen algorithm parameters. Station Sensor StdDev #Obs 2.8*sd 1:Bias 2:Slope 3:Pcor 4:Tcor 5:Wt 6:Lag 1-9 353 0.345 17 0.966 -0.033 0.004650 0.0001642* -0.03072 0.9699* -0.2047* 10-24 353 1.041 158 2.915 -0.102 0.005428 0.0001642* -0.04609 0.9699* -0.2047* 25-32 353 1.049 99 2.937 -0.098 0.005386 0.0001642* -0.05041 0.9699* -0.2047* 33-44 353 1.564 142 4.379 -0.088 0.005268 0.0001642* -0.04460 0.9699* -0.2047* 33-35 381 1.739 27 4.869 -0.075 0.005122 0.0001561* -0.04220 0.7771* 6.927* 36-38 381 1.809 41 5.065 -0.043 0.005155 0.0001451* -0.03588 0.7908* 6.111* 40-43 381 1.151 50 3.223 -0.073 0.005469 0.0001536* -0.04226 0.7629* 2.239* 44-46 381 0.851 35 2.383 -0.094 0.005693 0.0001588* -0.04635 0.7355* 2.040* 47-50 381 1.745 32 4.886 -0.221 0.007512 0.0001538* -0.08644 0.7243* 5.715* 51-56 381 0.627 47 1.756 -0.086 0.005724 0.0001559* -0.04680 0.7322* 4.255* 57-59 381 1.273 33 3.564 -0.049 0.005230 0.0001556* -0.03296 0.7769* 3.391* 60-66 381 0.851 81 2.383 -0.041 0.005237 0.0001520* -0.03243 0.7619* 5.183* 67-69 381 0.796 33 2.229 -0.034 0.005228 0.0001501* -0.03139 0.7214* 5.801* 70-76 381 1.267 82 3.548 -0.035 0.005273 0.0001498* -0.03199 0.7582* 3.632* 77-81 381 1.160 60 3.248 -0.039 0.005165 0.0001539* -0.02756 0.6860* 6.501* 82-90 381 1.114 105 3.119 -0.034 0.005239 0.0001509* -0.02980 0.7111* 4.469* 91 381 1.125 13 3.150 -0.074 0.004804 0.0001774* -0.01653 0.7987* 4.997* 92-95 381 1.646 48 4.609 -0.090 0.004880 0.0001780* -0.02040 0.8516* 8.153* 96-97 381 2.251 23 6.303 -0.099 0.005156 0.0001758* -0.02914 0.8620* 2.643* 98-99 381 1.849 25 5.177 -0.067 0.005115 0.0001626* -0.02800 0.8482* 10.850* 100-104 381 1.098 59 3.074 -0.056 0.005207 0.0001575* -0.03242 0.8902* 9.426* 105-109 381 0.668 56 1.870 -0.025 0.005138 0.0001472* -0.03311 0.9373* 5.558* 110-119 381 1.105 89 3.094 -0.056 0.005247 0.0001587* -0.03249 0.8042* 6.654* 120-130 381 3.152 195 8.826 0.031 0.004859 0.0001209* -0.03049 0.9413* 4.374* * Fixed parameter from full water column fit of all bottles (sensor 353) or each grouping (sensor 381). FIGURE 4*: Calibrated CTD-bottle oxygen differences plotted against station number (upper panel). Calibrated-bottle oxygen differences plotted against pressure (lower panel). FIGURE 5*: Potential temperature (°C) sections. Contour intervals are 0.1 from 1 -2°C, 0.2 from 2-3°C, 0.5 from 3-5°C, and 1 from 5-35°C. FIGURE 6*: Salinity (PSS-78) sections. Contour intervals are 0.001 from 34-35, 0.05 from 35-35.1, and 0.1 from 35.1-38. FIGURE 7*: Potential density (kg/m3) sections. Sigma-theta contour intervals are 0.5 from 22-26, 0.2 from 26-26.4, and 0.1 from 26.5- 27.4. Sigma-2 contour intervals are 0.1 from 36.5-36.9, 0.05 from 36.9-37, and 0.01 from 37-37.05/ Sigma-4 contour intervals are 0.02 from 45.82-48. Figure 8*: CTD oxygen (µmol/kg) sections. Contour intervals are 10 from 100-300 µmol/kg in the upper panel; 10 from 100-250 µmol/kg, and 5 from 250-300 µmol/kg in the lower panel. TABLE 3: Weather condition code used to describe each set of CTD measurements. Code Weather Condition ---- -------------------------------------- 0 Clear (no cloud) 1 Partly cloudy 2 Continuous layer(s)of cloud(s) 3 Sandstorm, dust storm, or blowing snow 4 Fog, thick dust or haze 5 Drizzle 6 Rain 7 Snow, or rain and snow mix d 8 Shower(s) 9 Thunderstorms TABLE 4: Sea state code used to describe each set of CTD measurements. Code Height (meters) Description ---- --------------- -------------- 0 0 Calm-glassy 1 0 - 0.1 Calm-rippled 2 0.1 - 0.5 Smooth-wavelet 3 0.5 - 1.25 Slight 4 1.25 - 2.5 Moderate 5 2.5 - 4 Rough 6 4 - 6 Very rough 7 6 - 9 High 8 9 - 14 Very high 9 >14 Phenomenal TABLE 5: Visibility code used to describe each set of CTD measurements. Code Visibility ---- ------------------ 0 < 50 meters 1 50 - 200 meters 2 200 - 500 meters 3 500 - 1,000 meters 4 1 - 2 km 5 2 - 4 km 6 4 - 10 km 7 10 - 20 km 8 20 - 50 km 9 50 km or more All CTD and Hydrographic Data can be obtained by contacting K.E. McTaggart at kem@pmel.noaa.gov. *All figures shown in PDF file. WHPO DATA PROCESSING NOTES Date Contact Data Type Data Status Summary -------- ---------- --------- ------------------------------------------ 12/07/99 Baringer BTL Data Requested by d.bartolocci Also, may we make these data public, or should they be encrypted on our website? Would you be able to provide an estimated date for submission of the bottle file so we may update our records? 12/07/99 Baringer DOC Submitted 12/07/99 McTaggart CTD/SUM Submitted I've transferred 130 CTD data files, along with the .SUM file, from the 1998 OACES/ACCP trans-Atlantic cruise along 24N (WHPID A6) to the WHPO ftp site, whpo.ucsd.edu, subdirectory /INCOMING. Also find six text files of documentation and tables, and ten postscript files of figures representing the published documentation in the NOAA data report, "CTD/O2 Measurements Collected on a Climate and Global Change Cruise Along 24N in the Atlantic Ocean (WOCE Section A6) During January-February 1998" (ERL PMEL-68). A bottle data file (.SEA) will be submitted by Dr. Molly Baringer at a later date. 12/14/99 Bartolacci CTD/SUM Update Needed expocode too long, probs w/ lat/lon both sumfile and ctd files need work. The sumfile has bad lat/lons on line 256 and 311, and some of the columns have "NA" in them that cause sumchk to barf. I'm assuming that the expocode will need to be changed as well. 02/22/00 Huynh DOC Doc Update pdf, txt versions online 05/12/00 Bartolacci CTD Website Updated; CTD data status is public 05/22/00 Kappa DOC ctd report added to text file 08/24/00 Mele SUM Submitted error: station 102; 29 95 N should be 29.95 N. there is a missing decimal place in the beginning position for station 102 in the sum file for ar01_a. -- phil mele 11/08/00 Bartolacci BTL Data Request sent to M. Barringer WHPO DATA PROCESSING NOTES Date Contact Data Type Data Status Summary -------- ---------- --------- ------------------------------------------ 11/27/00 Bartolacci SUM Data file Reformatted, online I have replaced the current file with the reformatted file and updated all references to reflect this change. NOTE: The line number for this cruise has been changed from the Chief Scientist's designation (of A06) to the WHP-ID AR01 11/28/00 Bartolacci CTD Data file Reformatted, online I have replaced the current online CTD files with the newly reformatted files (by D. Muus) and edited all references to reflect this change. Notes on merging reside in a ctd subdirectory in the original subdir. for this cruise. 11/28/00 Muus CTD Reformatted by WHPO AR01_a EXPOCODE 31RBOACES24N_2 CTD Stations 1-130. o Changed EXPOCODE in all ctd files from 31RBOACES24N/2 to 31RBOACES24N_2. o Changed WHP-ID from A6 to AR01. o Added WHPOSIO version number. o Changed file names from cg198w001.ctd to ar01_a0001.wct etc. cg198w130.ctd to ar01_a0130.wct o Changed from 1db interval to 2db interval and corrected No. RECORDS=. o Plotted all files and ran wctcvt. No apparent errors. Many stations between 033 and 101 had noisy oxygen values (+/- 3uM/L) WHPO DATA PROCESSING NOTES Date Contact Data Type Data Status Summary -------- ---------- --------- ------------------------------------------ 01/31/01 Diggs BTL Data Requested from M Baringer 2001.01.22 S. Diggs telephones M. Baringer requesting bottle file. No reply as of 2001.01.31. 06/29/01 Uribe CTD Website Updated EXCHANGE File Added CTD have been converted to exchange format and put online. 01/20/02 Bartolacci BTL/CO2 Submitted I have obtained a version of the bottle file for this cruise from Alex Kozyr at CDIAC as per Piers Chapmans suggestion. Currently the file is in OceanDataView format, NOT anywhere near WOCE format. I have placed the file in the original subdirectory for this cruise and have sent an email to Lee (Chi Sci) to request the file in another ascii format. Also requested public status of file. This email was copied to M. Baringer the data contact for this data. No formatting has taken place on these data yet, it is difficult to see what parameters are in the file at this time. Another RCS will be submitted once parameters are confirmed. As per Alex Kozyr, CO2 data has not yet been dqe'd and he is awaiting the file con-version into WOCE format in order to dqe these parameters. 01/25/02 Bartolacci BTL Submitted Data added to website ctdprs, ctdtmp, ctdsal, ctdoxy, theta, salnty, oxygen, silcat, nitrat, nitrit, phspht, cfc-11, cfc-12, cfc113, ccl4, tcarbn, alkali, ph Comma separated bottle file was obtained from aoml website as per B. Huss (data contact for this cruise). File also contained parameters not tracked by WOCE (TOC, TON, FCO220C FCO2INSITU, CTALK [different from TALK]). File has been linked online although no reformatted has taken place at this time. All data are public as per Lee. Please note that Baringer is not data contact for this file all queries are to be directed to B. Huss. 02/01/02 Tibbetts DOC Website Updated New pdf and txt docs online. 04/10/02 Lebel CFCs Final CFC data submitted The file: ar05.dat - 648867 bytes has been saved as: 20020410.123624_LEBEL_AR01_ar05.dat in the directory: 20020410.123624_LEBEL_AR01 The data disposition is: Public The file format is: Plain Text (ASCII) The data type(s) is: Other: final CFC data The file contains these water sample identifiers: Cast Number (CASTNO) Sample Number (SAMPNO) LEBEL, DEBORAH would like the following action(s) taken on the data: Merge Data Place Data Online Update Parameters additional notes: o Final CFC data for 24.5N section. o Scale is SIO98, o units are pmol/kg. o Includes QUALT2 word for CFCs. 04/24/02 Bartolacci BTL Update Needed CSV file needs reformatting. 07/22/02 Buck SUM Website Updated Station numbers changed to match CTD Preceding zeroes were added to the SUMFILE station numbers to match them with the CTD station numbers. WHPO DATA PROCESSING NOTES Date Contact Data Type Data Status Summary -------- ---------- --------- ------------------------------------------ 09/10/02 Bartolacci BTL Reformatted; generated exchange file 00_README- this file o BOTTLE- version of bottle file used by first attempt at reformatting by KJU o BOTTLE.bck- ditto o BOTTLE_NOHEAD- ditto o ar01_ALL_PARAMS_2003.01.11.txt- WOCE formatted version of the bottle fileas output from conv_prcsn.pl o ar01_ALL_PARAMS_20030402.txt- WOCE formatted version of above without CTALKparameter which was left out at recommendation of A. Kozyr (CarbonDQE) o ar01_ahy.txt - a copy of above file which was wocecvt tested and passedwith only pressure inversion warnings. o ar01_a_hy1_handmade.Exchange- Hand made exchange file containing all original parameters created from original data file. Those parameters that are not tracked by WOCE were renamed to fit into the WOCE 6char. naming convention with the exception of FCO220C. Following headers were changed accordingly: o SIGMATHETA to STHETA; o TALK to ALKALI; o CTALK to CALKAL; o FCO2INSITU to FCO2IN. o Unknown parameter names for the following were retained until consultation: FCO220C, TOC, TON. o All flag headers were changed to woce exchange format headers for flags. NOTE: **CALKAL has been deleted from this file at the recommendation of A. Kozyr. Also castno. -9 were changed to 1 and leading station number was split off of bottle number (eg. bottle 101 changed to 1, etc.) This file was originally put up before bottle file was woce formatted and converted to exchange using software** o ar01_a_hy1.Exchange- exchange file converted using jjward's software using the woce formatted file ar01_ahy.txt as input. NOTE: this file does not contain the non-WOCE params such as STHETA or any FCO2 params. Convertion code will not use non- WOCE params for output. o ar01_a_nc_hyd.zip- netCDF files created using software from ar01_ahy1.Exchange.no errors were produced during convertion, also no non-WOCE params included in this file. o ar01_a_inv_hyd.txt- inventory file created from software. no errors produced.used excel to view, and file appears correct. o ar01_ahy_cols.txt- copy of original bottle file in 8 char. fields not Exchange. o fix_bottle.pl - Bren and Karla's script (unfinished) for formatting o conv_prcsn.pl hacked code to rewrite a file containing all parameters iwthcorresponding flags in the correct positions (it was found that of the other files are incorrect with this respect). o conv_prcsn2.pl version of above code without CTALK in output (this parameterwas dropped at the recommendation of A. Kozyr carbon DQE) 09/19/02 Uribe BTL Website Updated; File converted to exchange Bottle file was converted to exchange and netcdf files were made accordingly. Bottle file contained -9 as CastNo so they were changed to 1s to match the sumfile. Exchange file was viewed with JOA and no problems were apparent. 09/19/02 Uribe BTL Website Updated; exchange & netcdf files made Bottle file was converted to exchange and netcdf files were made accordingly. Bottle file contained -9 as CastNo so they were changed to 1's to match the sumfile. Exchange file was viewed with JOA and no problems were apparent. 02/12/03 Bartolacci BTL Website Updated; Data Merged into OnLine File ctdprs, ctdtmp, ctdsal, ctdoxy, theta, salnty, oxygen, silcat, nitrat, nitrit, phspht, cfc-11, cfc-12, cfc113, ccl4, tcarbn, alkali, pco2, ph, qualt1 I have formatted the entire bottle file into woce format. in addition to the above parameters the bottle file also contains the following non-woce parameters and (quality flags) AOU, STHETA, CTALK, FCO220C, FCO2IN, TOC, TON. New bottle file is online and xml & html files have been regenerated. 04/24/03 Anderson ALKALI Data file updated o Made new exchange file. o Made the ALKALI correction and generated a new exchange file. The one thing I noticed is that there are no SAMPNO's, so -9 has been put in that field in the .txt file and -999 in the exchange file. o Changed ALKALI value at station 109 bottle 7 from 0.0 to -9.0 o Changed the QUALT1 flag from 2 to 9 re A. Kozyr's e-mail below: "Please regenerate the ar01_a_hy1.csv file for repeat AR01 section. There is something wrong with this file and it is not acceptable by ODV. May be -9.0 should be -999.0 or something else. Please change the ALKALI value in the .txt file for station 109 bottle 7 from 0.0 to -9.0 and flag fro this value from 2 to 9 before you generate a new .csv file." - B. Kozyr 04/30/03 Kappa DOC Updated online cruise reports o Combined: "NOAA Data Report 0AR AOML-41" (CHEMICAL AND HYDROGRAPHIC MEASUREMENTS) and o "NOAA Data Report ERL PMEL-68" (CTD/O2 MEASUREMENTS) in both the pdf and text reports o Updated data processing notes in pdf and text reports NOAA/AOML DATA PROCESSING NOTES Date Contact Data Type Data Status Summary -------- ---------- --------- ------------------------------------------ 08/13/99 Huss BTL Data update Calculated THETA, SIGMATHETA, and AOU. 08/19/99 Peng/Huss BTL Data update Release of Version A of the 24N98 database. 01/05/00 Huss TCARBN Submitted/merged Merged TCO2 into the master database. Received the data from Marilyn Roberts. 01/12/00 Huss BTL Data update Merged O2, FO2, CTDSAL, CTDOXY, FBOTTLE (bottle qc flag) update into the database. 01/15/00 Peng/Huss BTL Data update Release of Version B of the database. 04/05/00 Huss TCARBN/PH Submitted/merged Merged the TALK and pH update into the database. Received the data from Dr. Millero. 04/28/00 Huss NUTs Submitted/merged Merged the nutrient update (received from Calvin Mordy). 05/01/00 Huss NUTs Submitted/merged Merged the nutrient update (received from Calvin Mordy). 05/03/00 Huss TCARBN Data update Received the TCO2 update from Marilyn Roberts. Merged into the database. 05/08/00 Huss TON Data update Received TON update from Dennis Hansell. Converted TON and TOC from umol/L to umol/kg and merged the data into the database. NOAA/AOML DATA PROCESSING NOTES Date Contact Data Type Data Status Summary -------- ---------- --------- ------------------------------------------ 05/09/00 Huss CTD Submitted Received CTD data. This data was extracted from the file 24nbottle2.dat obtained from Molly Baringer. This is considered the final CTD and O2 data. NOTE: Station 39 trip information was reconstructed from the calibrated CTD data upcast. Values should be considered questionable. Full data file with conductivities and information from both sensors can be obtained from Molly Baringer, baringer@aoml.noaa.gov. 05/09/00 Huss TCARBN Data update Added station 1. Added TCO2 and fCO2 data for station 1. Modified database to include a bottom depth field and entered the bottom depths. 05/09/00 Huss TCARBN Final data submitted Received the final fCO2 update from Rik. Merged the data into the database. In February 2000, Kitack Lee noticed an offset in the fCO2 data. It was associated with using the wrong tank calibration value. This data was reduced using the right standard (508.35). Thus 547.37 was replaced by 508.38 in the program. Then it was run against all data files again. The quality of the data was checked performing an internal consistency check of DIC, TALK by fCO2. Outliers in fCO2 were labelled a "3". 05/09/00 Huss ALKALI Updated QC flags Changed TALK QC flags for sample numbers 1301, 9007, 9421, 10221, and 10225 to 3 (questionable). Corrected pH values for sample numbers 12621 and 13006. 05/10/00 Huss THETA/AOU Recalculated/merged Recalculated THETA and AOU using the updated CTD data. Merged data into the database. 05/11/00 Huss CFCs Submitted/Merged Received CFC11 and CFC12 update from John Bullister. Merged the data into the database. NOAA/AOML DATA PROCESSING NOTES Date Contact Data Type Data Status Summary -------- ---------- --------- ------------------------------------------ 05/13/00 Huss ? data update Changed all longitude values to negative (East). 06/26/00 Huss NUTs Submitted Received nutrient update from Dr. Zhang and merged the data into the database. 08/28/00 Huss TCARBN Merged into database Merged TCO2 update into the database. Received data from Marilyn Roberts. 09/18/00 Huss CFCs Merged into database Merged the CFC113 and CCL4 (carbon tetrachloride) update into the database. Received data from John Bullister. 09/20/00 Peng/Huss BTL Data update Version C of the 24N98 database was released today. 10/30/00 Huss ALKALI Data update Changed TALK and FTALK for sample numbers 8401, 8402 and 8403 (station 84). 04/13/01 Huss TALK New field added to database Added a new field called CTALK (Calculated TALK) and mergedthe calculated TALK data into the database. Update received from Kitack Lee. NOAA/AOML DATA PROCESSING NOTES Date Contact Data Type Data Status Summary -------- ---------- --------- ------------------------------------------ 05/08/01 Huss BTL Data Updates prior to submisson to WHPO This file is a chronology of changes and/additions to the master database for the 24 North 1998 cruise which took place from late January thru February, 1998. The database contains the final data. AOU DATA The apparent oxygen utilization, AOU (umol/kg) is calculated as the solubility for oxygen at the measured salinity and potential temperature minus the observed oxygen concentration. The solubility for oxygen at the measured salinity and potential temperature is determined from the algorithms presented in Weiss (1970). Note that at low temperature, the solubility determined by Weiss is up to 2 umol/kg higher than determined by Benson and Krause (1984) or Garcia and Gordon (1992). Weiss, R.F., The solubility of nitrogen, oxygen and argon in water and seawater, Deep-Sea Research, 17, 721-735, 1970. TALK Data Total alkalinity (TALK) is calculated using spectroscopic pH (25†C) and coulometric TCO2 using the carbonic acid dissociation constants of Mehrbach et al. (1973) as refit by Dickson and Millero (1987). The of 1.2 umol/kg has been subtracted from calculated total alkalinity CTALK) values because calculated values are 1.2 umol/kg higher than measured values. PLEASE NOTE the following updates have been received but not incorporated in the current version. The most recent version with these updates can be obtained from Betty Huss (huss@aoml.noaa.gov): None - all data received up to May 8, 2001 have been incorporated in Version D. The 24N98 dataset includes the following files: 24N98D.EXCHANGE 24N98D.DBF 24N98.QC 24N98.DES where the EXCHANGE file contains the data in comma-delimited format, the QC file contains the explanation of the quality control flags and the DES file is a chronological descrip-tion of all changes/updates to the dataset. 05/08/01 Huss TOC/TON Updated sample numbers Added QC Flags for TOC and TON. Modified FO2 for sample number 4401 modified FTCO2 for sample number 8502, and FNO3, FSIO4 and FTCO2 for sample number 10601.