If symbols do not display correctly change your browser character encoding to unicode A. CRUISE NARRATIVE: AR15, AR04W and AR04E Updated APR 2014 A.1 Highlights WHP Cruise Summary Information WOCE section designation AR15 Expedition designation (EXPOCODE) 35LLETAMBOT1 Chief of Project Claude Oudot Chief Scientist Yves Gouriou Centre ORSTOM B.P. 70 29280 Plouzane France Telephone: (33) 02 98 22 45 10 Telefax: (33) 02 98 22 45 14 e-mail: gouriou@orstom.fr Cruises Dates Sept. 9, 1995 to Oct. 11, 1995 Ship R/V LE NOROIT Port of Call 1st leg: Cayenne (French Guiana) to Natal (Brazil) 2nd leg: Natal (Brazil) to Cayenne (French Guiana) Number of stations 85 8°23.65' N Geographic boundaries of stations 51°33.37'W 34°55.27' W 0°0.1' N Floats and drifters deployed 0 Moorings deployed or recovered 0 A.2 Cruise Summary Cruise Track The cruise track and station locations are shown in Figure 1. First leg: Cayenne (4°51'N-52°15'W) to 35°W-3°S. Second leg: Natal (5°48'S-35°18'W) to 35°W-3°S, transit to 0°23'N-45°06'W, then 0°23'N-45°06'W to Cayenne. Number of station A total of 85 CTD/rosette stations were occupied using a General Oceanics 24 bottle rosette equipped with: • 24 8-liter Niskin water sample bottles. • a NIBS Mark IIIa CTD equipped with an oxygen sensor, and bottom proximity alarm. • a 12 kHz MORS pinger. • a 150 KHz-RDI L-ADCP (Lowered Acoustic Doppler Current Profiler). To install the L-ADCP, 2 Niskin bottles have been removed from the rosette. Due to bad weather conditions, there is no station at 35°W-3°S. Sampling Double casts were performed for deep stations (bottom > 4500 m). During the first cast 6 water samples were taken between the surface and 500 m, and during the second cast 22 water samples were taken between 500 m and the bottom. The number of water samples per station is distributed as follows: 15 shallow stations with less than 22 water samples. 37 stations with 22 water samples. 18 stations with 24 water samples (L-ADCP removed from the rosette). 11 stations with 28 water samples (double casts). 3 stations with 30 water samples (double casts and L-ADCP removed from the rosette). Salinity, dissolved oxygen, nutrients (nitrate, nitrite, silicate, phosphate) have been measured for every sample, at every station. Freons (11 and 12) measurements were performed at every station. Between 800 m and the bottom for 75 stations, and between the surface and the bottom for 10 stations. Total dissolved CO2 and pH measurements were carried out for all the closed bottles every other station (47 stations). Surface sampling were carried out at each station to determine CO2 fugacity and chlorophyll. Test stations: Station N°25: all the bottles closed at 1000 m depth. Station N°85: 12 bottles closed at 1000 m depth, and 12 bottles closed at 2000 m depth. At every station 2 bottles were closed at the same depth. Floats, Drifters, and Moorings No floats, drifters, or moorings were deployed on this cruise. A.3 List of Principal Investigators TABLE 1: Principal investigators Name Responsibility Institution -------------------- ---------------- ----------- Chantal Andrie Freons ORSTOM Bernard Bourles S-ADCP, Salinity ORSTOM Yves Gouriou CTD, L-ADCP ORSTOM Claude Oudot Nutrients - O2 ORSTOM Jean-Francois Ternon CO2 parameters ORSTOM A.4 Scientific Program and Methods The principal objectives of the cruise were: • To estimate the inter-hemispheric transport of heat, freshwater, nutrients, CO2, and CFCs in a key region of the Atlantic ocean. • To estimate the seasonal variability of the deep circulation. A second cruise, ETAMBOT 2, have been made in an opposite season. • To repeat the survey of the western equatorial Atlantic ocean made during the CITHER 1 cruise in January-March 1993 (Western part of the A6 section). The instruments employed in the measurement program consisted of a NBIS Mark IIIa CTD and General Oceanics rosette. Subsidiary instrumentation consisted of a 12 kHz pinger, a bottom proximity alarm, and a L-ADCP. 6 SIS reversing pressure meters and 6 SIS reversing thermometers were installed on the bottles. After a cast the rosette was placed on the deck and secured. The rosette, the frame, sensors and L-ADCP were watered with fresh water. L-ADCP binary data were downloaded to a PC. Digital instrumentation was read and samples were drawn in the following order: Freons, oxygen, CO2 parameters, nutrients, and salinity. The rosette was stored on deck throughout the cruise and all sampling was performed there. Acoustic Doppler Current Profiler (ADCP) measurements were made continuously employing a hull mounting 150 kHz unit manufactured by RDI. No continuous water depth measurements were performed along the track of the ship. A deep sounder was used to locate the rosette during the cast. A.5 Major Problems Encountered on the Cruise One station, at 3°S-35°W, has been cancelled due to bad weather condition. Consequently we did not finish the 35°W section and we sailed to Natal (Brazil). After the call in Natal we carried out the stations between 5°S-35°W and 3°30'S-35°W. Again we were not able to make the station at 3°S. Due to a failure of two L-ADCP acoustic transponders, deep velocity profiles were made only from station N°2 to station N°32 (i.e. 31 velocity profiles). 2 SIS reversing pressure meters and 1 reversing thermometers failed during the cruise. A.6 List of Cruise Participants TABLE 2: Cruise participants Name Responsibilities Affiliation Leg -------------------- -------------------------- ---------------- Chantal Andrie CFCs ORSTOM 1-2 Francois Baurand Nutrients ORSTOM 1-2 Jean-Michel Bore Elec. Engineer/CTD/L-ADCP ORSTOM 1-2 Bernard Bourles CTD/S-ADCP ORSTOM 1-2 Elisabete Braga Nutrients IOUSP 1-2 Remy Chuchla Oxygen ORSTOM 1-2 Christian Colin CTD ORSTOM 2 Denis Diverres CO2 ORSTOM 1-2 Gerard Eldin CTD/S-ADCP ORSTOM 1 Philippe Fournier Salinity ORSTOM 1-2 Yves Gouriou Chief Scientist/CTD/L-ADCP ORSTOM 1-2 David Nowicki CTD/L-ADCP ORSTOM 1-2 Claude Oudot CO2 ORSTOM 1-2 Jean-Francois Ternon CFCs ORSTOM 1-2 ORSTOM: Institut Francais de Recherche Scientifique pour le Developpement en Cooperation IOUSP: University of Sao Paulo B. UNDERWAY MEASUREMENTS B.1 Navigation By B. Bourles Navigation data (time, position, course and speed over ground, and fix quality information) were acquired throughout the ETAMBOT-1 cruise, from the 09/09/1995 at 11h05 TU, every 15 seconds with a Magnavox MX4200 Global Positioning System (GPS). Due to a failure of this GPS, the vessel NALNO GPS was used during the second part of the cruise, from the 09/28/1995 at 13h30 TU to the 10/10/1995 at 15h45 TU. B.2 Echosounding None. B.3 Acoustic Doppler Current Profiler (ADCP) By B. Bourles The Ship mounted Acoustic Doppler Current Profiler (S-ADCP) system on board the N/O LE NOROIT is a 153 kHz RD-VM150 Instruments unit with a hull mounted transducer. The four-beam transducer is mounted in a well, filled with fresh water and closed by a Kevlar acoustic window, and located to the port side around the vessel centerline at 4 meters depth. It is connected by cable to a deck box, containing the processing equipment, and connected to a Personnal Computer (AT-286) dedicated to measurement acquisition. Ship's gyrocompass information are collected by the deck box through a synchro to digital interface. Data were collected using the RDI Data Acquisition Software (version 2.48). Information exchanges between the S-ADCP and the acquisition PC were managed by the 'ENSOUT' RDI software. Navigation data (time, position, course and speed over ground, and fix quality information) were acquired with a Magnavox MX4200 Global Positioning System (GPS) during the first part of the cruise, and with the vessel NALNO GPS during the second part. Standard setup parameters used were: 8 meter bin and pulse lengths, 4 meter blanking, and 5 minutes ensemble averaging. A reference layer was defined between bins 5 to 15. The first bin was centered on 16 meter depth. The S-ADCP data processing has been made using the Common Oceanographic Data Access System (CODAS-3, version 3) of the Hawaii University (Bahr et al., 1990). The PC-clock drift is first determined by comparing PC time with GPS time. This time drift did not exceed 2 to 3 seconds per day. The corrected time is then included in the data base. Navigation and transducer temperature are first checked. 'Noisy' bins or profiles are suppressed. Navigation and S-ADCP measurements are combined in order to obtain absolute current values. The currents velocity is calibrated using the Pollard and Read (1989) standard procedure. Absolute velocity profiles were obtained down to about 300 m depth on station, and down to 190 m depth when steaming (the vertical extension is defined by the depth where the percentage of good bins per ensemble becomes inferior to 30%). The original 5 minutes profiles have been averaged into 'in stations', 'between stations', '1/4 degree' and 'hourly' profiles. Standard deviation of velocity mean profiles is of the order of 3 cm s-1. References: Bahr, F., E. Firing and S. Jiang, Acoustic Doppler current profiling in the western Pacific during the US-PRC TOGA Cruises 5 and 6, JIMAR Contr. 90- 0228, U. of Hawaii, 162 pp., 1990. Pollard, R. and J. Read, A method for calibrating ship-mounted acoustic Doppler profilers, and the limitations of gyro compasses, J. Atmos. Oceanic Technol., 6, 859-865, 1989. B.4 L-ADCP measurements By B. Bourles, Y. Gouriou, R. Chuchla The Lowered Acoustic Doppler Current Profiler (L-ADCP) allows to provide absolute currents over the whole water column. We used a BroadBand 150 kHz RD Instruments ADCP. It was attached to the 'rosette', and two water bottles were removed from the 'rosette' frame for L-ADCP installation. The L-ADCP acquires velocity profiles during the down and up casts, simultaneously to the CTD-O2 system. The CTD-O2/L-ADCP package was lowered and raised at a nominal speed of 1 m s-1, except during the upcast when the package was stopped to fire the bottles. We used the following setup parameters: one second sampling rate, one ping per ensemble, 19 bins per ensemble, 16 meter bins width, sea water salinity of 35 and sound velocity of 1500 m s-1. Thus, a velocity profile of about 300 m vertical extent is acquired every second. Each ensemble contains the precise time, internal sensor temperature, heading, pitch and roll angles, and vertical velocity of the rosette. Data of each bin contain the three velocity components in earth coordinates, velocity error estimate, backscattered energy and quality parameters (e.g., 'percent good'). Data have been processed following the method described by Fischer and Visbeck (1993), and adapted by Gouriou and Hemon (1997). As the L-ADCP did not have pressure sensor, the depth of each cell was computed using the vertical velocity measurements. Then, all the individual profiles were combined in a unique velocity profile over the whole water. At depth, data perturbed by the bottom reflections were suppressed. The reference velocity was determined using the GPS time and position at the beginning and at the end of the profile. Error due to this reference velocity determination is estimated to 1 cm s-1 (Fischer and Visbeck, 1993). However, the precision of the L-ADCP measurements is difficult to evaluate at this stage, except in the surface layers by comparison with Ship mounted Acoustic Doppler Current Profiler measurements, where maximum mean differences reach 5 cm s-1. Due to the failure of two of the four L-ADCP transducer beams, thirty-two (over eighty-five CTD-O2 casts) absolute velocity profiles were acquired at the beginning of the Etambot-1 cruise. References: Fischer, J., and M. Visbeck: Deep velocity profiling with self-contained ADCPs, J. Atmos. Oceanic Technol, 10(5), 764-773, 1993. Gouriou, Y., and C. Hemon: Traitement des donnees L-ADCP, Centre ORSTOM de Cayenne, documents scientifiques n° O.P. 21, 56pp, 1997. B.5 Thermosalinograph measurements None B.6 XBTs B.7 Meteorological Measurements By B. Bourles Meteorological measurements were recorded every three hours, from the 09/09/1995-12h00 TU to the 10/10/1995-18h00 TU, by the deck officer of the R/V LE NOROIT. These measurements are the following: date, time, position, dry thermometer temperature (°C), moist thermometer temperature (°C), dew point temperature (°C), sea level pressure (mbar), sea level temperature (°C), and relative humidity (%). Weather, clouds and sea level conditions have not been recorded. Wind measurements were erroneous due to direction correction problems. C. HYDROGRAPHIC MEASUREMENTS TECHNIQUES AND CALIBRATIONS C.1 Sample Salinity Measurements By P. Fournier and C. Oudot Salinity analysis of samples collected during ETAMBOT 1 were carried out onboard with a GuildlineTM PortasalTM salinometer model 8410, equipped with an OSI (Ocean Scientific International) peristaltic-type sample intake pump. The instrument was operated in the container-laboratory kept at a constant temperature of 23°C. The bath temperature of the salinometer was adjusted to 24°C. Standardization was effected by use of IAPSO Standard Seawater batch P123 (K15 = 0.99994). Every day, the standardization was adjusted before one run of analysis and the standardization drift was checked every two stations (44 samples). The drift was very low: on the average it was - 0.00002 ± .00045 psu. Quality control of the salinity data were performed using repeated measurements from replicate samples (bottles fired at the same depth at station N°25 and N°85) and duplicate samples (two different bottles fired at the same depth, sixty-nine times). The standard deviations of the three groups of replicate samples are given in the Table 3 below. TABLE 3: Salinity replicate statistics Station number 25 85 ---------------------- -------- --------- Pressure (dbar) 997 2001 Number of bottles 12 12 Mean salinity (psu) 34.7542 34.9779 Maximum deviation (psu) .0008 0.0010 Standard deviation .0004 .0006 The standard deviation of the sixty-nine sample pairs (duplicate), taken at different depths, is 0.0009 psu. C.2 Sample Oxygen Measurements By P. Fournier and C. Oudot Sampling and techniques Oxygen samples were taken in calibrated clear glass bottles (capacity = 120 cm3) immediately after the drawing of samples for CFCs. The temperature of the water at the time of sampling was measured to allow the conversion of the concentration unit per volume into per mass. The fixing of the dissolved oxygen is immediately performed with reagents before the closure of the glass bottle, according to the method recommended in the WOCE Operations Manual (Culberson, 1991). The samples were stored in the container-laboratory (controlled temperature of 23°C) where analyses were carried out, according to the Winkler whole bottle method. All volumes of glassware to collect samples and to dispense solutions were calibrated by weight, and corrections were made for changes in volume with temperature. The end-point was determined by automatic potentiometric method with a MetrohmTM TitratorTM model 682 and a DosimatTM 665 burette (10 cm3). The concentration of oxygen dissolved in seawater was converted to mass fraction by use of the following relationship: [µmol kg-1] = (44.660 / rho-sw) * O2 [cm3 dm-3] where rho-sw is the density of the seawater corresponding to the temperature at the sampling time (Millero and Poisson, 1981). Reproducibility of measurements The precision of measurements was estimated from analysis of three groups of replicate (taken from different bottles fired at the same depth) samples and a large number (sixty-nine) of duplicate (two bottles fired at the same depth, changing from one station to the other) samples during successive stations. Table 4 gives the statistics of replicates. TABLE 4: Oxygen replicate statistics Station number 25 85 --------------------------------- ----- ------ Pressure (dbar) 997 2001 Number of bottles 22 12 Mean O2 concentration (µmol kg-1) 153.3 252.1 Maximum deviation (µmol kg-1) 1.8 1.0 Standard deviation (µmol kg-1) 0.8 0.4 The standard deviation of the sixty-nine sample pairs (duplicate) is 0.4 µmol kg-1, i.e. a value not significantly different from reproducibility of replicates, excepted the first station (# 0), carried out as a trial station. Comparisons with historical data Comparisons of ETAMBOT 1 data with historical data (SAVE Leg 6, 1989 and TTO- TAS, 1983) are shown in Figure 2. The right insets exhibit the deepest levels. Excepted differences in the upper layers resulting from changes in water masses in the region, principally in bottom panel (TTO-TAS) where the latitude range is wider, the agreement is satisfactory. References Culberson C.H., 1991. Dissolved oxygen in the WOCE Operations Manual. Vol. 3, Part 3.1.3: WHP Operations and Methods. WHP Office Report WHPO 91-1, WOCE Report N° 68/91. Millero F. J. and A. Poisson, 1981. International one-atmosphere equation of state of Sea Water. Deep Sea Res., 28, 625-629. C.3 Nutrients By F. Baurand and C. Oudot Equipment and techniques Nutrient analyses were performed on a Braun & LuebbeTM AutoAnalyzerTMII type TechniconTM (continuous flow analyzer), according to classical methods (Murphy and Riley, 1955 for silicate - Murphy and Riley, 1962 for phosphate - Wood et al., 1967 for nitrate and nitrite) as described in the Manual of Treguer and Le Corre (1975). Colorimeter signals were processed with an IBM computer using a home-made software (Lechauve et al., 1992). Sampling for nutrient analysis followed those for gases (freons, oxygen, CO2 fugacity, total CO2 and pH) and were carried out in Nalgene bottle (125 cm3). Samples were stored until analysis (the maximum delay is six hours) in the container-laboratory controlled in temperature (22°C). The Nalgene bottles were put on the special sample tray of the AutoAnalyzer in such a way as the samples were directly taken from the sampling bottles without transfer via traditional polystyrene cups. Calibration and standards Volumes of glassware (volumetric flasks and MetrohmTM automatic burette model DosimateTM 665) to prepare standards were checked by weight in the shore- laboratory, at a temperature near that in the container-laboratory (22°C). Nutrient primary standards were prepared from salts (BakerTM, anal. grade., certified 99.99 %, for phosphate, nitrate and nitrite ; Carlo ErbaTM, high purity for silicate) dried at 105°C for two hours. Four primary standards were prepared ashore prior the cruise by dissolving: 0.85056 g of potassium dihydrogenophosphate in 1 liter of ultrapure water 12.63875 g of potassium nitrate in 1 liter of ultrapure water 8.62500 g of sodium nitrite in 1 liter of ultrapure water 2.35075 g sodium silica fluoride in 5 liters of ultrapure water No buoyancy correction were applied to the nominal weights. The ultrapure water was deionized water with a resistivity of 18 M‡. The primary standard solutions were preserved with chloroform (2 ml per liter). A mixed secondary standard for phosphate + nitrate and a single secondary standard for nitrite were prepared weekly by dilution with deionized water. Seven working standards were prepared every day in artificial water. Concentrations (µmol l-1) were: 0, 10, 20, 40, 60, 90, 120 for silicate ; 0, 0.25, 0.50, 1.00, 1.50, 2.50, 3.00 for phosphate ; 0, 5, 10, 20, 30, 40 for nitrate ; 0, 0.50, 1.00, 1.50, 2.00 for nitrite. The artificial seawater was a 40 %o solution of analytical grade sodium chloride. The linearity of the calibration curve (Beer's Law) was not valid beyond 20 µmol l-1 for silicate and nitrate. So, a polynomial (cubic) relationship was chosen for those nutrients. Quality control The precision of measurements was estimated from analysis of three groups of replicate (taken from different bottles fired at the same depth, during three test stations) samples and a large number (seventy) of duplicate (two bottles fired at the same depth, changing from one station to the other) samples during successive stations. Table 5 gives the statistics of replicates. The percent standard deviations (vs full range) are 0.1 for silicate, 0.5 for phosphate and 0.3 for nitrate, in agreement with WHP recommendations (WOCE, 1994). TABLE 5: Nutrients replicate statistics Silicate Station number 25 85 85 ---------------------------------------- ------ ------- ------ Pressure (dbar) 997 2001 997 Number of bottles 22 12 12 Mean silicate concentration (µmol kg-1) 27.18 17.43 27.95 Standard deviation (µmol kg-1) 0.13 0.05 0.12 Percent standard deviation 0.46 0.27 0.43 Percent standard deviation (vs full range, 120 µmol kg-1) 0.11 0.04 0.10 Phosphate Station number 25 85 85 ---------------------------------------- ------ ------- ------ Pressure (dbar) 997 2001 997 Number of bottles 22 12 12 Mean phosphate concentration (µmol kg-1) 2.12 1.28 2.26 Standard deviation (µmol kg-1) 0.01 0.00 0.01 Percent standard deviation 0.68 0.35 0.70 Percent standard deviation (vs full range, 3 µmol kg-1) 0.48 0.15 0.53 Nitrate Station number 25 85 85 ---------------------------------------- ------ ------- ------ Pressure (dbar) 997 2001 997 Number of bottles 22 12 12 Mean nitrate concentration (µmol kg-1) 30.98 19.39 33.17 Standard deviation (µmol kg-1) 0.12 0.03 0.06 Percent standard deviation 0.39 0.17 0.18 Percent standard deviation (vs full range, 40 µmol kg-1) 0.30 0.08 0.15 The standard deviation of the seventy sample pairs (duplicate) is 0.4 µmol kg-1 for silicate, 0.02 µmol kg-1 for phosphate and 0.3 µmol kg-1 for nitrate. The consistency of phosphate and nitrate data is shown in Figure 3 by the strong correlation between these two nutrients (R2 = 0.9914). The slope of the regression line (15.016) is in good agreement with the Redfield ratio. Comparisons with historical data Comparisons of ETAMBOT 1 data with historical data (SAVE Leg 6, 1989 and TTO- TAS, 1983) are shown in Figure 4. The right insets exhibit the deepest levels. Excepted differences in the upper layers resulting from changes in water masses in the region, principally in bottom panel (TTO-TAS) where the latitude range is wider, the agreement is satisfactory. References Lechauve J.J., Baurand F. and C. Oudot, 1992. Manuel d'utilisation ASTECH (Analyse du Signal TECHnicon). Doc. Techn. Centre ORSTOM de Brest, n° 67, 35 p. Mullin J.B. and J.P. Riley, 1955. The spectrophotometric determination of silicate-silicon in natural waters with special reference to sea water. Anal. Chim. Acta, 12: 162-170. Murphy J. and J.P. Riley, 1962. A modified simple solution method for the determination of phosphate in natural waters. Anal. Chim. Acta, 27: 31-36. Treguer P. and P. Le Corre, 1975. Manuel d'analyse des sels nutritifs dans l'eau dde mer (utilisation del'AutoAnalyzer II Technicon). Universite de Bretagne Occidentale, Brest, 2eme edition., 110 p. WOCE , 1994. WOCE Operations Manual. Vol. 3, Part 3.1.3: WHP Operations and Methods. WHP Office Report WHPO 91-1, WOCE Report N° 68/91, Revision 1, November 1994. Wood E.D., Armstrong F.A.J. and F.A. Richards, 1967. Determination of nitrate in sea-water by cadmium-copper reduction to nitrite. J. Mar . Biol. Ass. U.K., 47 : 23-31. C.4 CFC-11, CFC-12 by C. Andrie Work on board During the cruise, two people had in charge sampling and analysis of water samples for CFC measurements. Sea water samples were directly taken from Niskin bottles using syringes with metallic stopcocks. All of the samples at the surface and samples corresponding to depths greater than 800 m have been taken. This corresponds to at least 17 samples per profile or 22 when double casts have been realized for bottom depth greater than 4500 m. Complete profiles have been realized for 11 stations (stations 5, 6, 36, 42, 57, 64, 65, 67, 69, 70, 81). Atmospheric measurements have been realized every two days, from syringe samples. Globally, 2580 analyses have been realized, including standards and atmospheric analyses. The usual precautions have been taken before and during the boarding: Niskin bottles cleaned and stored in a ventilated area in Cayenne before the cruise and then Decon washed on board, bottles rings heated (60°C) and degassed in an oven just at the beginning of the cruise. Analyses and data validation The gas chromatographic method with electron capture detection is described in Bullister and Weiss (1988), with some minor modifications. The gas vector is ultrapure nitrogen. Validation has been done, for each station, from vertical F11 and F12 profiles and F11/F12 diagrams. Seven F12 data have been rejected (all F11 data have been kept). The atmospheric secondary standard has been calibrated against a SIO primary standard during four times during the cruise. CFC concentrations are reported in the SIO 1986 scale. The reproducibility, for the standard, for the whole cruise, was ± 0.9% for F12 and ± 2.2% for F11. Mean atmospheric mixing ratio were 514 ppt (± 1.6 ") for F12 and 270 ppt (± 3.4 %) for F11. The atmospheric distribution shows an inter-hemispheric gradient around 0.46 ppt/° lat for F12 and 0.3 ppt/° lat for F11. Reproducibility over all the measurements is 2% for F12, 3.5% for F11, 3.2% for F11/F12. Calibration has been done using a 6 levels x2 curve. Analytical performances The detection limit of the method is obtained during test-stations where all the bottles have been closed at the same level, corresponding to a near-zero CFC content. There is not true CFC-free waters in the ETAMBOT area. Our mean contamination level has been determined through a statistical method of the test-stations, the CFC content evolution at 1000 m depth (low CFC Upper Circumpolar Water) and a comparison with CITHER1 (A6 and A7 WHP lines) results. The detection limit determined through the standard deviation over the test- stations at 1000 m (stations 25 and 85) is around 0.004 pmol.kg-1 for F12 and 0.01 pmol.kg-1 for F11. We have examined the evolution of the F11/F12 ratio at the 1000m level in order to separate the part of bottles contamination to the part of the sampled water. Two groups of stations are identified: • Stations 5 to 23 with high F11/F12 ratio (7.3 ± 3): for this set, an important contamination part is evident. The respective contamination levels are 0.002 pmol.kg-1 for F12 et 0.033 pmol.kg-1 pour F11. • Stations 24 to 84 with lower F11/F12 ratio (2.7 ± 1). For this set the mean. Contamination levels are 0.002 pmol.kg-1 for F12 and 0.007 pmol.kg-1 for F11. These contamination levels have been systematically removed from the CFC values. References Bullister, J.L., and R.F. Weiss, Determination of CCl3F and CCl2F2 in seawater and air, Deep-Sea Res., 35, 839-853, 1988. C.5 Samples Taken for Other Chemical Measurements CO2 system parameters by J.F. Ternon and C. Oudot Total inorganic carbon (TCO2) Measurements of TCO2 were made by gas chromatography, according to the method described by Oudot and Wauthy (1978). The method basically consists of gas stripping of the seawater sample (1 cm3) after acidification, and of the gas chromatographic analysis of the gas mixture allowing the TCO2 separation and quantification. Routine calibration of the measurements was performed using liquid standard solutions prepared at the laboratory prior the cruise, according to a procedure adapted from the Goyet and Hacker (1992) technique. Primary calibration is done by using the Certified Reference Material delivered by A.G. Dickson (Scripps Institution of Oceanography). Samples were taken from the surface to bottom, every two stations. Quality control of TCO2 data has been performed using repeated measurements (duplicate) at each station (two bottles fired at the same depth ; different depth at each station), and "test" stations (all of the bottles closed at the same depth). Results for test stations are shown in Table 6. TABLE 6: TCO2 replicate statistics Station number 25 85 85 ------------------ ------ ------ ------ Depth (dbar) 997 2001 997 Number of bottles 22 12 11 TCO2 (µmol kg-1) 2196.1 2197.7 2121.6 Standard deviation (µmol kg-1) 8.2 10.3 8.4 Repeatability of TCO2 measurements was determined from statistical analysis of duplicate results, according to the relationship (Dickson and Goyet, 1994): S = (Sigma-di2 / 2n)1/2 where di = difference for pair i and n = number of pairs (32). For Etambot 1 cruise S = 6.8 µmol kg-1. pH The pH measurements were performed according to the potentiometric method on the total hydrogen ion concentration pH scale (Dickson (1993). The total hydrogen ion concentration, [H+], is expressed as moles per kilogram of sea water. Measurements were made using a combination glass/reference electrode ORION(TM) type ROSS(TM) and a pHmeter ORION(TM) model 720A (resolution = 0.1 mv, i.e. 0.0017 pH units). The Nernst response of the electrode was checked in the shore-based laboratory before and after the cruise with two buffers: 'Tris' and '2- aminopyridine'. The pH electrode was calibrated against the 'Tris' buffer before every serial of measurements (every station), and the drift was estimated during each station (22 samples) for correction. The mean drift during a station, throughout the cruise, was 0.1-0.2 mV, i.e. 0.002-0.003 pH units. Seawater samples and buffers were thermostated at 25°C and the temperature was measured with a platine probe (± 0.01°C). Then, pH data were corrected to in situ conditions (temperature and pressure) according to the relationships of Millero (1995) for temperature and Millero (1979) for pressure. Samples were taken from the surface to bottom, every two stations. Quality control of pH data has been performed using repeated measurements (duplicate) at each station (two bottles fired at the same depth ; different depth at each station), and "test" stations (all of the bottles closed at the same depth). Results for test stations are shown in Table 7. TABLE 7: pH replicate statistics Station number 25 85 85 ------------------ -------- --------- -------- Depth (dbar) 997 2001 997 Number of bottles 21 11 12 PH 7.983 8.041 7.880 Standard deviation 0.0020 0.0014 0.0027 Repeatability of pH measurements was determined from statistical analysis of duplicate results, according to the relationship (Dickson and Goyet, 1994): S = (Sigma-di2 / 2n)1/2 where di = difference for pair i and n = number of pairs (33). For Etambot 1 cruise S = 0.002 pH units. Total alkalinity Total alkalinity, AT, is defined as the number of moles of hydrogen ion equivalent to the excess of following bases formed from weak acids in one kilogram of sample: AT = [HCO3-] + 2 [CO32-] + [B(OH)4-] + [OH-] - [H+] AT, expressed in µeq kg-1, was estimated as the sum of the components of the right member of the previous relationship, calculated from TCO2 and pH measurements. The used equilibrium equations and thermodynamic data for carbonic acid, boric acid and water are identical to those reported in Dikson and Goyet (1994). Samples were taken from the surface to bottom, every two stations. Quality control of AT data has been performed using repeated measurements (duplicate) at each station (two bottles fired at the same depth ; different depth at each station), and "test" stations (all of the bottles closed at the same depth). Results for test stations are shown in Table 8. TABLE 8: AT replicate statistics Station number 25 85 85 ----------------------------- ------ ------ ------ Depth (dbar) 997 2001 997 Number of bottles 21 12 11 AT (µeql kg-1) 2307.7 2294.8 2303.8 Standard deviation (µeq kg-1) 7.8 8.1 10.9 Repeatability of AT measurements was determined from statistical analysis of duplicate results, according to the relationship (Dickson and Goyet, 1994): S = (Sigma-di2 / 2n)1/2 where di = difference for pair i and n = number of pairs (32). For Etambot 1 cruise S = 7.0 µeq kg-1. CO2 fugacity The fugacity of CO2 in seawater was determined in air that was in equilibrium with a discrete sample of seawater. The fugacity, fCO2, is related to the partial pressure, pCO2 , by the relation (Weiss, 1974) to take into account the non-ideality of CO2: fCO2 = pCO2 exp{(B + 2delta) patm / RT} The partial pressure of CO2 in wet air is calculated from the molar fraction of CO2 in dry air, xCO2, the atmospheric pressure, P , and the H2O vapor pressure, pH2O (Weiss and Price, 1980): pCO2 = xCO2 p = xCO2 (P - pH2O) The molar fraction of CO2 in equilibrated air was measured with an IR analyzer LI-COR(TM) model LI6262 . The analyzer was calibrated with three standard gases (329.0 - 349.6 - 407.7 ppm), produced by a French manufacturer, Air Liquide, in agreement with the scale of the Scripps standards. During the cruise, duplicate seawater samples were taken from only the surface bottle of the General Oceanics rosette and analyzed as described in Oudot et al. (1995). Besides, the measurement of atmospheric CO2 concentration was made twice a day by pumping an air stream taken at a mast at the bow of the vessel. Then, the CO2 fugacity measured at 28°C was corrected for in-situ temperature according to the temperature dependence equation of Copin-Montegut (1989). The reproducibility of fCO2 measurements was determined from statistical analysis of 63 pairs of duplicate results, according to the relationship (Dickson and Goyet, 1994): S = (Sigma-di2 / 2n)1/2 where di = difference for pair i and n = number of pairs (63). For Etambot 1 cruise S = 2.9 µatm. Chlorophyll a and Phaeophytin by C. Oudot and J. Neveux During the cruise, seawater samples were taken from only the surface bottle of the General Oceanics rosette for determination of chlorophyll and phaeopigments as described in Neveux and Lantoine (1993) by the spectrofluorometric method. Seawater was filtered on Whatman GF/F filter (diameter = 47 mm, porosity = 0.45 µm). The filters were stored at -25°C until the analysis in the shore-based laboratory. References Copin-Montegut C., 1989. A new formula for the effect of temperature on the partial pressure of CO2 in seawater. Mar. Chem., 27, 143-144 Dickson A.G., 1993. pH buffers for seawater media based on the total hydrogen ion concentration scale. Deep Sea Res., 40, 107-118. Dickson A.G. and C. Goyet, 1994. Handbook of Methods for the Analysis of the various Parameters of the Carbon Dioxide System in Srea Water. Version 2, US. DOE, SGRP-89-7A. Goyet C. and S.D. Hacker, 1992. Procedure for the calibration of a coulometric system used for total inorganic carbon measurements in seawater. Mar. Chem., 38, 37-51. Millero F.J., 1979. The thermodynamic of the carbonate system in seawater. Geochimica et Cosmochimica Acta, 43,1651-1661. Millero F.J., 1995. Thermodynamics of the carbon dioxide system in the oceans. Geochimica et Cosmochimica Acta, 59, 661-677. Neveux J. and F. Lantoine, 1993. Spectrofluorometric assay of chlorophylls and phaeopigments using the least squares approximation technique. Deep Sea Res., 40, 1747-1765. Oudot C. and B. Wauthy, 1978. Adaptation of a gas chromatograph for shipboard measurement of dissolved gases: nitrogen, oxygen and carbon dioxide (in French). Cah. ORSTOM, ser. Oceanogr., 16, 89-102. Oudot C., J.F. Ternon and J. Lecomte, 1995. Measurements of atmospheric and oceanic CO2 in the tropical Atlantic: 10 years after the 1982-1984 FOCAL cruises. Weiss R.F., 1974. Carbon dioxide in water and seawater: the solubility of a non- ideal gas. Mar. Chem., 2, 203-215. Weiss R.F. and B.A. Price, 1980. Nitrous oxide solubility in water and seawater. Mar. Chem., 8, 347-359. C.6 CTD MEASUREMENTS The following equipment was deployed on the CTD/multisampler underwater frame: 1. Neil Brown Mark IIIa with a polarographic Beckman sensor 2. General Oceanics 8-liter 24 bottle rosette. 3. 6 SIS digital reversing thermometers and 6 SIS digital reversing pressure meters. 4. MORS 12 kHz pinger 5. A bottom proximity alarm 6. L-ADCP 140kHz RDI. 2 bottles have been removed. CTD data were acquired through an EG&G demodulator, with the OCEANSOFT 1 software. Data were stored on a PC. Raw analogic data were stored on DAT system. The rosette was not equipped with the non-data interrupt rosette firing module. We had no problems with the rosette and the bottles were fired at the desired depths. C.7 CTD Data Collection and Processing By Y. Gouriou Temperature Calibration The temperature sensor of the CTD was calibrated before and after the cruise, on June 9, 1995 and December 15, 1995. The temperature sensor has been controlled for the following temperature: 0°C, 5°C, 10°C, 15°C, 20°C, 25°C, 30°C. The calibration results are presented on figure 5. Between the pre- and post- calibration the temperature sensor presents a drift of: • 0.010°C in average • 0.012°C at a temperature of 0°C (maximum) • 0.008°C at a temperature of 10°C, 15°C, and 20°C (minimum). We considered that the incertitude on the temperature measurements is of ±0.005°C. The solid line represents the 5th order polynomial adjustment applied to the CTD temperature measurements. The CTD temperature has been compared to SIS reversing thermometer measurements. The SIS thermometers have been calibrated before and after the cruise, at the same dates than the CTD temperature sensor. The figures 6 show the temperature difference between the SIS and CTD measurements. The SIS and CTD temperature data have been calibrated before the comparison. The figures 6 show a drift of the temperature difference from the station N°1 to the station N°35. That drift is not confirmed by the other comparisons (figures 6). In a first step the CTD temperatures have been corrected from that drift, but the calibration of the salinity sensor was not satisfactory, as confirmed by the comparisons of the theta-S diagrams of the ETAMBOT 1 cruise with the CITHER 1 cruise (WHP Line A7). We then decide not to correct the CTD temperatures from the drift observed. Note that: • If the CTD temperature sensor presents a drift of 0.011°C (at a laboratory temperature of 5°C) between the pre- and post-calibration, the SIS thermometer also drifted. The SIS thermometer T-106 and the SIS thermometer T-7 present a drift of 0.009° +C and 0.007°C respectively. • As the rosette was not equipped with a non-data interrupt rosette firing module, the CTD measurements (temperature, conductivity, oxygen) were perturbed when a bottle was closed. It is likely that the precedent comparison suffered from that deficiency. Pressure Calibration The pressure sensor of the CTD was calibrated before and after the cruise, on June 9, 1995 and December 15, 1995. In order to estimate the hysteresis of the pressure sensor, laboratory calibration have been performed: 1 - for increasing pressure (down casts) 2 - for decreasing pressure (up casts) The pressure sensor did not drift a lot during the 6-months interval (2 dbar at maximum) and the difference between the pre-calibration and post-calibration is constant at every depth (Figure 7). We fitted the results of the calibration with a 5 order polynomial curve. The CTD down-cast pressure measurements are calibrated by using the coefficients obtained in the laboratory for increasing pressure, at a temperature of 20°C. For the up casts we used the calibration coefficients obtained in the laboratory for decreasing pressure, at a temperature of 15°C. This was an arbitrary choice, as we had no means to know the temperature of the pressure CTD sensor. The use of two different reference temperatures, for the up- and down-cast calibration, induced different pressure values at 6000 m (Figure 7). The discrepancy is negligible at 5000 m, the maximum depth of the measurements. For the shallow casts (depth < 500 m) we used only the calibration coefficients obtained for increasing pressure, estimating that the hysteresis is negligible. The pressure measured by the CTD can be compared to the SIS digital reversing pressure meters. The SIS have been calibrated in the laboratory before and after the cruise at the same date than the CTD pressure sensor. The calibration has been made at a temperature of 2°C close to the temperature at which they were used. The figures 8 present the pressure difference between the SIS and CTD measurements before calibration. The solid line represents the calibration curve (SIS+CTD pressure) we should apply to that difference. The comparisons show that the SIS corrected pressure and CTD corrected pressure are equal with an incertitude of 5 dbar. Salinity Calibration The calibration of the CTD conductivity sensor is made by comparing the CTD conductivity measurements, at the depth where the bottles are closed, to the in-situ conductivity of the water samples. The CTD conductivity measurements are corrected from the temperature and pressure effect on the conductivity cell. The CTD conductivity measurements are calibrated using a linear regression. The polynomial coefficients are computed iteratively. IMPORTANT The rosette was not equipped with a non-data interrupt rosette firing module. Due to this deficiency, the conductivity measurements were perturbed during the up-cast. We judged the perturbation sufficiently important to modify the normal calibration procedure: to find the calibration coefficients, we compared the water sample conductivity to the CTD conductivity measurements of the DOWN-cast instead of the UP-cast. We used the pressure of the up-cast water sample to find the CTD conductivity in the down-cast profile. This method is similar to that used for the calibration of the oxygen sensor. That procedure gave correct results, but has the disadvantage of eliminating an important number of water samples between the surface and 1500 dbar. CALIBRATION Note that: • We used the same CTD conductivity sensor during the whole cruise. • The CTD conductivity sensor has been cleaned before stations N°20, N°50, and N°71. • The stations made in shallow water (bottom < 1500 m) are: N°1, N°2, N°3, N°4, N°5, N°58, N°63, N°64, N°65. TABLE 9: Calibration coefficient for the CTD conductivity sensor Number of Number of Standard deviation Coefficients Stations used samples Retained samples (0 - 6000 m) C1 C2 -------- ------------ ---------------- ------------------ ------------------ 1 -> 14 246 181 0.0039 1.000318 -0.02146 15 -> 21 159 119 0.0019 1.002110 0.07511 22 -> 24 78 64 0.0029 1.003115 -0.12824 26 -> 27 55 45 0.0030 0.999611 0.00476 28 -> 37 243 187 0.0018 1.001014 -0.03890 38 -> 56 413 331 0.0018 1.000381 -0.01719 57 24 23 0.0065 0.997654 0.06776 58 -> 62 81 54 0.0021 1.000008 -0.00415 63 -> 70 124 104 0.0018 1.000123 -0.01022 71 -> 84 345 264 0.0014 1.000399 -0.02139 1847 water samples have been taken out during the cruise. Eliminated the samples of the test stations N°25 and N°85, as well as the bad measurements, we retained 1768 water samples for the calibration. 1372 comparisons have been retained by the minimization process (77.6% of the measurements). The figure 9 shows the resulting conductivity difference after the calibration procedure. Only the station N°57 presents an important dispersion as the measurements between the surface and 1500 m have not been rejected by the minimization process (that station being calibrated separately). The difference is lower than 0.001 mmho cm-1 for 23% of the samples. The difference is lower than 0.003 mmho cm-1 for 60% of the samples. CONTROL To control the quality of the calibration, theta-S diagrams have been compared: 1. Between successive stations of the cruise. 2. Between stations made at the same position during the cruise (N°27 and N°82). 3. Between different cruises. 1. theta-S diagrams of consecutive stations made during the cruise have been systematically compared. The differences (>= 0.0005), for potential temperature lower than 1.9°C, have been systematically reported in the following table. The difference is positive when the station in the first column has a salinity greater than the station in the second column. TABLE 10: Salinity comparison between contiguous profiles of the ETAMBOT 1 cruise ETAMBOT 1 ETAMBOT 1 Salinity Station Number Station Number Difference -------------- -------------- ----------- 8 9 0.0020 10 11 0.0010 19 20 0.0005 21 22 0.0020 22 23 0.0005 23 24 0.0010 24 26 -0.0050 30 31 0.0005 34 35 0.0005 37 38 -0.0010 49 50 0.0005 50 51 -0.0005 55 56 0.0005 69 70 -0.0005 70 71 0.0010 71 72 -0.0005 Remarks * Station N°8 and N°9: the 0.0020 difference is observed above 2°C. Other tracers also show properties differences. * Station N°21 and N°22, and station N°24 and N°26 (station N°25 is a test station): No error have been found in the sample analysis that could explained the observed difference. The comparison between the theta-S diagrams of these stations and stations made at the same locations during the CITHER 1 cruise (WHP A6 line) confirm the differences observed (see below). 2. The comparison of the stations made at the same position during the cruise (N°27 and N°82) show that there are perfectly superimposed for potential temperature smaller than 1.9°C (Figure 10). 3. Comparison with preceding cruises The ETAMBOT 1 cruise repeats exactly the western track of the CITHER 1 cruise, along the 7°30'N latitude and 35°W longitude. Excluding shallow stations, about 40 theta-S diagrams have been compared. The result of that visual comparison is shown in the following table. Only the stations where the differences are equal or greater than 0.0005 are reported: TABLE 11: Salinity comparison between ETAMBOT 1 and CITHER 1 profiles ETAMBOT 1 CITHER 1 Salinity Station Number Station Number difference -------------- -------------- ---------- 11 129 -0.0010 16 134 -0.0005 19 137 0.0005 22 140 -0.0020 23 141 -0.0035 24 142 -0.0050 35 154 -0.0005 36 155 -0.0005 The comparison is good except for the station N°22, 23, and 24. The differences observed for those stations are coherent with the differences observed between the stations N°21 and N°22, and the station N°24 and N°26 of the ETAMBOT 1 cruise. We then decide to correct the salinity profiles of the stations N°22, N°23, and N°24: 0.0020 has been added to the CTD salinity profile of station N°22. 0.0035 has been added to the CTD salinity profile of station N°23. 0.0050 has been added to the CTD salinity profile of station N°24. Furthermore the theta-S diagrams of the repeated-ETAMBOT 1 stations N°27 and N°82 are perfectly superimposed with the theta-S diagrams of the CITHER 1 station N°144 (Fig. 11), for potential temperatures lower than 1.9 deg C. Oxygen Calibration The same CTD oxygen sensor has been used during the whole cruise. CTD oxygen were calibrated by fitting to sample values using the method described in Owens and Millard [1985] . 1847 oxygen samples have been gathered during the cruise. Excluding the samples of the test stations N°25 and N°85 as well as the bad sample analysis, 1777 samples have been used to calibrate the data. 1667 samples (93.8%) have been retained during the fitting process. The following Table shows the results of the calibration: TABLE 12: Calibration result for the oxygen sensor Number of Number of Standard deviation Station Number used samples retained samples (0-5000 m) µmol kg-1 -------------- ------------ ---------------- ------------------- 1 -> 6 72 66 1.7 7 -> 10 88 85 1.8 11 22 20 0.9 12 22 22 2.6 13 22 19 0.7 14 21 20 1.2 15 21 21 1.4 16 22 22 1.1 17 22 22 1.0 18 21 21 0.8 19 22 22 1.3 20 21 21 0.7 21 28 28 1.7 22 28 27 1.7 23 28 27 1.0 24 -> 26 53 53 1.8 27 -> 30 99 95 1.2 31 -> 35 124 111 1.2 36 22 20 0.7 37 -> 38 43 42 1.5 39 22 22 2.4 40 22 22 1.5 41 22 21 0.9 42 21 19 0.4 43 -> 46 86 82 1.6 47 -> 49 64 62 1.5 50 -> 54 108 97 1.1 55 -> 57 70 64 1.6 58 -> 62 81 72 1.8 63 -> 70 130 115 1.3 71 -> 83 326 303 1.7 84 24 24 1.7 The figures 12 show the differences, in µmol kg-1, between the oxygen samples and the down-cast CTD measurements. The difference is lower than 1 µmol kg-1 for 33% of the samples . The difference is lower than 2 µmol kg-1 for 74% of the samples . CONTROL The figure 13 shows the CTD oxygen profiles of the repeated station N°27 and N°82. The profiles are well adjusted to the oxygen samples. The difference observed at the bottom disappears on the theta-O2 diagram. As for the salinity profiles, the comparison with the oxygen profiles of the CITHER 1 have been made. Along the 7°30'N latitude the comparison is good (figure 14). Along the 35°W longitude some systematic differences are observed: they are reported in the following Table: TABLE 13: Oxygen comparison between ETAMBOT 1 and CITHER 1 profiles ETAMBOT 1 CITHER 1 Oxygen difference Station number Station number in µmol kg-1 -------------- -------------- ----------------- 37 119 -3.0 38 118 -3.0 39 117 -4.0 40 116 -4.0 41 115 -3.0 42 114 -1.5 43 113 -2.0 46 111 -3.0 47 110 -3.0 48 109 -2.0 50 107 -1.0 51 106 -1.0 52 105 -2.0 53 104 -2.0 54 103 -1.5 55 102 -2.5 These differences are generally observed between 2000 m and the bottom (Figure 15a). For every cruise the CTD oxygen profiles are well fitted to the samples. The bias observed seemed to be confirmed by the repeated stations performed during the CITHER 1 cruise at 7°30'N-35°W, station N°119 and N°156 (Figure 15b). As fifteen days separates those 2 stations we are not able to say if that difference is due to a natural variability. NOTE The CTD oxygen profiles have not been de-spiked. Some profiles show important spikes in the upper thermocline. The CTD oxygen profiles have not been filtered. Acknowledgements This project has been supported by ORSTOM as part of the Programme National d'Etude de la Dynamique du Climat, and its WOCE/France subprogramme. Figures caption Figure 1: Cruise track and station position. Figure 2: Oxygen versus salinity for ETAMBOT 1 and historical data (SAVE Leg 6 [35°W, 1°N to 1°S] and TTO-TAS [45°W-1°N to 41°W-7°30'N]). Figure 3: Nitrate - phosphate correlation for ETAMBOT 1 cruise data. Figure 4: Silicate versus temperature for ETAMBOT 1 and historical data (SAVE Leg 6 [35°W, 1°N to 1°S] and TTO-TAS [45°W-1°N to 41°W-7°30'N]). Figure 5: Temperature difference , in °C, between the laboratory reference temperature and the temperature measured by the probe. The solid represent the 5th order polynomial minimizing the differences.(+: calibration before the cruise. *: calibration after the cruise). Figure 6: Temperature difference, in °C, between SIS and CTD measurements (after calibration). Figure 6: Temperature difference, in °C, between SIS and CTD measurements (after calibration). Figure 6: Temperature difference, in °C, between SIS and CTD measurements (after calibration). Figure 7: Pressure difference, in dbar, between the laboratory reference pressure and the pressure measured by the probe. The solid represent the 5th order polynomial minimizing the differences. a) calibration for increasing pressure at a 20°C temperature (down cast). b) calibration for decreasing pressure at a 15°C temperature (up cast). Figure 8: Pressure difference, in dbar, between SIS and CTD measurements (before calibration). The solid line represents the sum of the SIS and CTD pressure correction to add to the pressure difference. Figure 8: Pressure difference, in dbar, between SIS and CTD measurements (before calibration). The solid line represents the sum of the SIS and CTD pressure correction to add to the pressure difference. Figure 9: Conductivity difference, in mmho/cm, between water sample and CTD measurements, after calibration. a) difference as a function of station number. b) difference as a function of pressure. Figure 10: theta-S diagram of repeated ETAMBOT 1 stations N°27 and N°82 (41°20'W-7°30'N). Figure 11: Comparison of the theta-S diagram of ETAMBOT 1 and CITHER 1 stations. a) ETAMBOT 1 station N°82 (41°20'W-7°30'N) and CITHER 1 station N°144 (41°20'W-7°30'N) b) ETAMBOT 1 station N°27 (41°20'W-7°30'N) and CITHER 1 station N°144 (41°20'W-7°30'N) Figure 12: Dissolved oxygen difference, in µ mol kg-1, between water sample and CTD measurements. a) difference as a function of station number. b) difference as a function of pressure. Figure 13: Dissolved oxygen profiles, in µ mol kg-1, of repeated stations N°27 and N°82 (41°20'W-7°30'N). *: water sample measurement of station N°27 x: water sample measurement of station N°82 Figure 14: Dissolved oxygen profiles, in µ mol kg-1. a) ETAMBOT 1 station N°27 (41°20'W-7°30'N) and CITHER 1 station n°144 (41°20'W-7°30'N). b) ETAMBOT 1 station N°19 (46°W-7°30'N) and CITHER 1 station N°137 (46°W-7°30'N). Figure 15: Dissolved oxygen profiles, in µ mol kg-1. c) ETAMBOT 1 station N°39 (35°W-7°N) and CITHER 1 station N°117 (35°W-7°N). d) CITHER 1 station N°119 (35°W-7°30'N) and CITHER 1 station N°156 (35°W-7°30'N DATA PROCESSING NOTES Date Contact Data Type Data Status Summary -------- ---------- ----------- -------------------------------------------------------- 04/23/98 Gouriou DOC Submitted; Paper version only 04/23/98 Gouriou CTD/BTL/SUM Submitted for DQE; Diggs had trouble w/ tar file 04/28/98 Gouriou CTD/BTL/SUM Submitted for DQE; data successfully received 03/10/99 Bartolacci CTD/BTL/SUM Website Updated *also DOC 02/08/00 Gouriou CTD/BTL Data are Public; All files need reformatting 07/18/00 Kappa DOC Doc Update; new pdf, txt versions created 07/20/00 Huynh DOC Website Updated; new pdf, txt versions online 11/21/00 Uribe DOC Submitted; See Note: 2000.11.21 KJU File contained here is CRUISE SUMMARIES and NOT sumfiles. Files listed below should be considered WHP DOC files. Documentation is online. 2000.10.11 KJU Files were found in incoming directory under whp_reports. This directory was zipped, files were separated and placed under proper cruise. All of them are sumfiles. Received 1997 August 15th. 12/14/01 Uribe SUM Data Reformatted Reformatted data online Sumfile was reformatted, had alignment problems. Passes Woce checks. 01/14/02 Uribe BTL Website Updated; CSV File Added, data reformatted Bottle has been converted to exchange and put online. Bottle file was reformatted. 03/12/02 Bartolacci CTD/BTL/SUM Data Reformatted Reformatted data online I have reformatted all files for this cruise. 00_README file containing reformatting notes resides in the original directory and will also be emailed to metadata manager. All newly edited files are now online and all references to these files have been edited to reflect these changes. NOTE: CTD files should now be ready for exchange conversion. 2002.03.12 DMB All files needed minor reformatting, the following edits were made: SUM- fixed station 19 cast 1 longitude minutes. Changed from 46 60.00 to 46 0.00 for BO and EN cast types. Three stations still are missing lat/lon values for at least one cast type within the entire cast (i.e. missing BO lat/lon but does have BE and EN lat/lon). Three stations are also missing UTC TIME for one of the three cast types. These are not errors, but do produce warnings in sumchk. No errors were produced. Added name/date stamp and placed edited file online, and previous file in original directory. BOT- Pressure sorted all stations. Some stations still retain duplicate pressure samples. Stations 25 and 85 tripped all/several bottles at same pressure. Ran wocecvt with no errors produced from bottle file (just warnings about lack of lat/lon for some summary file stations). Added name/date stamp and placed edited file online and previous file in the original directory. CTD- All CTD files had first two levels (0.00 and 2.00db) containing valid T/S/O data, but flags of 9, instead of 2. Station 36 had this problem for levels 0-6. I have edited the flags from 9 to 2 for all occurrences of this problem. Five stations (26, 29, 53, 60, 80) had mismatched dates when compared to the sumfile. This was due to the difference in time from BE to EN of each cast. Dates in these files were changed to match the sumfile dates. Ran wctcvt with no errors produced from the ctd files (just warnings from lack of lat/lon for some summary file stations) Rezipped all ctd files and replaced previously online files with new zipped file, moved old file to original directory. 2002.03.13 DMB CTD- After re-examining the data in the first two db levels of all CTD files for this cruise, it was determined that the identical values we in fact interpolated data (number of observations was 0. Because there is no WOCE flag to represent these values, the current flags will be left as is. This produces warnings for all stations with interpolated data when files are run through wctcvt diagnostic code, however are not considered formatting errors. Files have been rezipped and replaced previously edited zip file. 04/17/02 Uribe CTD Website Updated; Exchange file online CTD was converted to exchange and put online. 02/10/03 Bartolacci CTD, DOC Update Needed; lat/lon inconsistent, need CrsRpt For some time now we have been trying to clean up the last of the repeat cruises and incorporating current meter cruise data has fallen into this category. We were forwarded CTD data and two email correspondences by Jim Crease for the KN04 cruise. I am working on formatting these CTD files into a WOCE CTD format and a summary file. I am having some difficulties with the inconsistant lat/lon values recorded in the files. The values in the files that we obtained are are of differring precision and in some cases exceed any possible lat/lon value. Can you please help? We have no cruise or data documentation for these files and presently do not even know who the Chief Scientist was on cruise! Could you please forward a data contact with whom I might correspond to regarding these matters? We would like to button this up as soon as possible 12/17/13 Staff BTL Website Update; Available under 'Files as received' The following files are now available online under 'Files as received', unprocessed by the CCHDO. 35LU19950909_hy1.csv