CRUISE REPORT: P16_1984 (Updated NOV 2007) HIGHLIGHTS CRUISE SUMMARY INFORMATION WOCE section designation P16_1984 Expedition designation (ExpoCodes) 31WTMARAII Chief Scientists Roland A. de Szoeke/OSU Lynne D. Talley/SIO Dates 4 MAY 1984 to 4 JUN 1984 Ship R/V THOMAS WASHINGTON Ports of call Honolulu, Hawaii to Kodiak, Alaska 56° 18' N Geographic boundaries 157° 28.4' W 151° 56.1' W 21° 28.1' N Stations 98 Floats and drifters deployed 0 Moorings deployed or recovered 2 current meter moorings recovered Chief Scientists: Roland A. de Szoeke, Prof. Emeritus Lynne D. Talley, Professor Oregon State University Scripps Institution of Oceanography • UCSD Szoeke @coas.oreganstate.edu 9500 Gilman Dr. • MS 0230 • La Jolla, CA 92093 Phone: 858-534-6610 • Fax: 858-534-9820 ltalley@ucsd.edu • WWW: http://sam.ucsd.edu OREGON STATE UNIVERSITY COLLEGE OF OCEANOGRAPHY CORVALLIS, OREGON 97331 PHYSICAL, CHEMICAL AND CTD DATA from the MARATHON II EXPEDITION R/V Thomas Washington 261 4 May - 4 June 1984 by Margie Martin Lynne D. Talley Roland A. de Szoeke Data Report 131 National Science Foundation OCE-8316930 Reference 87-15 Office of Naval Research N00014-84-C0218 May 1987 CONTENTS Introduction Standard Procedures Data References Personnel Figures Cruise Track Vertical Sections Station List Tabulated Data and CTD Traces INTRODUCTION The hydrographic and CTD data presented in this report were collected aboard the RV Thomas Washington on the second leg of the Marathon Expedition, from Honolulu, Hawaii to Kodiak, Alaska (4 May - 4 June, 1984). The NODC identification number for the cruise is TW 261. The objective of the expedition was to provide information about the general circulation from the sea surface to the bottom in the northeastern Pacific with sufficient resolution along the cruise track to resolve the spacing of fronts and the scale of eddy variability. Except in boundary regimes at the beginning and end of the cruise where all stations extend from top to bottom, stations alternated between full water column coverage and coverage to 1500 meters. Station spacing between 28°N and 42°N was decreased in order to better sample the active frontal region. During the cruise, current meter moorings at 28°N and 42°N were retrieved and reset for P. Niiler by a separate group aboard the ship. The hydrographic and CTD data presented in this report were collected and processed by the Physical and Chemical Oceanographic Data Facility (now part of the Shipboard Technical Support Group) at Scripps Institution of Oceanography. The hydrographic and 2-db CTD data have been sent to the National Oceanographic Data Center. Note that there is no station 72 on the cruise. STANDARD PROCEDURES Hydrographic (Rosette) Data Each station consisted of a CTD lowering with a rosette carrying 24 Niskin bottles. Most stations included four reversing thermometer racks with one at the surface, one at the bottom, and the others at widely spaced intervals. Water samples were collected on the upcast and analyzed for salinity, oxygen, silicate, phosphate, nitrate, and nitrite. Samples for tritium analysis were collected for Dr. R. Fine and were processed by the Tritium Laboratory at the University of Miami. Pressure and temperature for the discrete hydrographic tabulations were taken from the calibrated CTD data. The CTD pressure and temperature calibrations are discussed in the following section. Occasional discrepancies between the bottom depth listed in the header record and the maximum depth of the station resulted from incompatibility of the depth as read from the PDR and the actual depth of the cast. Depths were calculated from CTD pressures (Saunders, 1981). Salinity samples were analyzed at sea using one of two Guildline Autosal inductive salinometers. All salinity values are calculated from conductivity using the 1978 practical salinity scale (UNESCO, 1981) and are tabulated to three decimal places. Standard seawater batch P92 was used to standardize the salinometer at the beginning and end of each station; salinities are reported relative to P92 and have not been adjusted further. Mantyla (1987) compared various batches of standard seawater with batch P96; he found that the salinity of P92 is about 0.003 ‰ less than that of P96. A section made in 1985 which intersected the Marathon II section and on which P96 was used as a standard showed salinities in the deep water which were indeed about 0.003 ‰ higher than Marathon II, indicating that the laboratory comparisons hold in situ and that the precision of the Autosal measurements is high. Bottle salinities were compared with CTD salinities to identify leaking bottles or salinometer malfunctions. Calibrated CTD salinities were used to replace bottle salinities in the event of problems and are indicated by the letter "D" in the hydrographic data tables. All salinities on station 34 were replaced by CTD salinities because of extensive drift in the autosalinometer standardization from the beginning to the end of that station's analysis; because the CTD salinities were calibrated using a large group of adjacent stations, the CTD salinities for station 34 are nearly as precise as those from bottle data. Dissolved oxygen was determined by the Winkler method as modified by Carpenter (1965), using the equipment and procedure outlined by Anderson (1971). A small number of oxygen values were discarded because contamination by rusty springs in the Niskin bottles resulted in low values. The bad springs caused greater problems with phosphate measurements. The precision of oxygen measurements is .01 mill and accuracy is 2%. Silicate, phosphate, nitrate and nitrite were analyzed at sea using an autoanalyzer. The procedures used are similar to those described in Atlas et al. (1971). Artificial seawater was used as a standard for the first 19 stations; this resulted in high values for all nutrients and was corrected by reducing the absorbance slope by 6.25% for these stations. During the early part of the cruise, the springs in a large number of Niskin bottles rusted as a result of inadequate coating. Most rusty springs were replaced after station 21. Phosphate measurements were the most strongly affected; hence a large number of phosphate measurements have been deleted from stations 1 to 21. Two bottles continued to cause problems on subsequent stations; all phosphate values from these bottles have been deleted. Oxygen measurements were also affected, but apparently less severely; oxygens have been deleted from a smaller number of stations. Silicate, nitrate, nitrite, and salinity values were apparently unaffected by the rusted springs. Nitrate measurements on station 80 have been deleted because of problems with the cadmium column in the autoanalyzer. A portion of the silicate values on station 87 were adversely affected by a 2°C change in the laboratory temperature and have been deleted. The precision of nutrient measurements is estimated to be less than .5% and accuracy is 2% to 3%. CONDUCTIVITY/TEMPERATURE/DEPTH (CTD) DATA A single Neil Brown Mark III CTD was used for all casts. The time series data were processed and calibrated by PACODF; the final product is a 2 db pressure series. Pressure, temperature, and conductivity were sampled at 32 frames/second and recorded on audio tape. Output from the oxygen probe was updated at 8 frames/second and recorded with the other three parameters; it was not processed. The audio tapes were digitized following the cruise. There was no obvious increase in noise due to digitization following the cruise; however, gaps in the final data for stations 13 and 42 resulted from yoyo's made to compensate for the ends of audio tape reels. Pressure, temperature and conductivity data were block-averaged in one second intervals. Values which were more than four standard deviations from the average were eliminated, the average was recalculated, and values more than 2 standard deviations from the average were discarded. The CTD pressure transducer was calibrated in a temperature-controlled bath to the PACODF Ashcroft deadweight-tester pressure standard. Thermal response-time, thermal hysteresis and mechanical hysteresis were measured. The mechanical hysteresis loading curves were measured at 0°C and 23°C and at maximum loadings of 2225 and 8825 PSI. The transducer thermal response time was derived from the pressure response to a thermal step change from 21°C to 0°C. There was no significant difference between pre- and post-cruise calibrations. Pressure calibrations were applied to the 1-second averages using a family of hysteresis curves based on the laboratory calculations. There was no significant drift in comparisons between CTD and thermometric pressures, based on reversing thermometers mounted on an average of 4 bottles on every cast. The mean difference between calibrated CTD pressures and thermometric pressures was 2.5 db. The CTD platinum resistance thermometer was calibrated in a temperature- controlled bath to the PACODF Leeds and Northrup PRT temperature standard at 0°C, 10°C and 25°C. Calibrations were performed before and after the cruise: there was a .002 to .003° decrease in the CTD temperature reading. In addition to a constant second-order slope applied to all casts as a result of the PRT calibrations, an offset that was linear as a function of time was applied to the full cruise to compensate for the shift between pre- and post-cruise calibrations. The mean difference between CTD temperatures and thermometer values was -0.0005°C. After pressure and temperature calibration, the up and downcast CTD salinities differed by no more than .001 ‰ in the deep water, except on a few stations which had obvious offsets in conductivity. Conductivity was calibrated using bottle salinities collected on the upcasts. Bottle sample conductivities were calculated from the sample salinities and from CTD pressures and temperatures. A conductivity slope correction was calculated as a third order least-squares fit to station number. After application of the slope correction, a conductivity offset for each cast was calculated and applied. All bottle samples were used for calibration with heavier weighting of samples below 1000 db. The mean difference between final CTD conductivities and sample conductivies was 0.00073 mhos. Additional offset corrections were made following comparisons of calibrated downcast salinities with bottle salinities in order to account for discontinuous shifts in the conductivity transducer response. After processing the time series, a roll filter was applied to eliminate pressure reversals and a 2 db pressure series was constructed by block- averaging all 1-second values within each 2 db bin. The final data set contains .46% missing data or 727 of 168,549 data points. Most missing data are at single levels and result from block-averaging in one second intervals followed by pressure sequencing. Eleven of the 98 stations account for 423 missing values, or more than half. The only blocks of missing data are 3422-3438 db at station 13 and 4438-4484 db at station 42, both due to large yo-yo's occasioned by operator compensation for the end of audio tape recordings. Seven upcasts were sent instead of downcasts because of major offsets or other instrument-related problems on the downcasts. The up-casts are stations 29, 50, 80, 82, 84, 85, and 89. DATA The data presentation consists of the cruise track, vertical sections, listings of all discrete hydrographic data, a subsample of the CTD data, plots of temperature and salinity as a function of pressure, and plots of potential temperature as a function of salinity. REFERENCES Anderson, G.C., compiler, 1971. "Oxygen Analysis," Marine Technician's Handbook, SIO Ref. No. 71-8, Sea Grant Pub. No. 9. Atlas, E.L., J.C. Callaway, R.D. Tomlinson, L.I. Gordon, L. Barstow and P.K. Park, 1971. A Practical Manual for Use of the Technicon (r) AutoAnalyzer (r) Nutrient Analysis; Revised. Oregon State University Technical Report 215, Reference No. 71-22. Carpenter, J.H., 1965. The Chesapeake Bay Institute technique for the Winkler dissolved oxygen method. Limnol. Oceanogr., 10: 141-143. Mantyla, A.W., 1987. Standard seawater comparisons updated. J. Phys. Oceanogr. (in press). Mantyla, A.W., 1980. Electrical conductivity comparisons of standard seawater batches P29 to P84. Deep-Sea Res., 27A, 837-846. UNESCO, 1981. Background papers and supporting data on the International Equation of State 1980. UNESCO Tech. Pap. in Mar. Sci., No. 38. PERSONNEL Ship's Captain Johnson, Curds D., RV Thomas Washington Scientific personnel participating in collection of hydrographic/CTD data de Szoeke Roland Professor College of Oceanography OSU (chief scientist) Talley Lynne D. Research Oceanographer Ocean Research Division SIO (co-chief scientist) Boaz John Marine Technician STS SIO Field Timothy J. Marine Technician PACODF SIO Hester Arthur W. Staff Research Associate PACODF SIO Martin Margie Staff Research Associate Marine Life Research Group SIO Mattson Carl W. Electronics Technician PACODF SIO Moe Ronald Programmer Shipboard Computer Group SIO Muus David A. Staff Research Associate PACODF SIO Paduan Jeffrey Graduate Student College of Oceanography OSU Wenzel Jan Graduate Student UH Additional personnel involved in data processing Beaupre Marie-Claude C. Staff Research Associate PACODF SIO Delahoyde Frank M. Programmer/Analyst PACODF SIO Johnson Mary C. Staff Research Associate PACODF SIO Sweet Paul Staff Research Associate PACODF SIO Wells James A. Marine Technician PACODF SIO ------------------------------------------------------------------------------ OSU Oregon State University PACODF Physical and Chemical Ocean Data Facility SIO Scripps Institution of Oceanography STS Ship Board Technical Support UH University of Hawaii FIGURES Figure 1. Station positions for the Marathon II section on the R/V Thomas Washington, May 4 - June 4, 1984. Figure 2. Bottle positions. Asterisks indicate irregularities in station numbering. Figure 3. Potential temperature section. Figure 4. Salinity section. Figure 5. Oxygen section. Figure 6. Silicate section. Figure 7. Phosphate section. Figure 8. Nitrate section. R/V THOMAS WASHINGTON MARATHON LEG 2 May 5, 1984 to June 4, 1984 Sta- Date Time Depth Number of tion GMT GMT Latitude Longitude M Samples ---- -------- ---- --------- ---------- ---- --------- 1 05/05/84 736 21 28.1 N 157 28.4 W 746 11 2 05/05/84 1342 21 35.9 N 157 21.1 W 3000 18 3 05/05/84 2054 21 57.2 N 157 4.5 W 18 4 05/06/84 724 22 18.0 N 156 48.0 W 3905 16 5 05/06/84 1330 22 30.5 N 156 26.0 W 4439 22 6 05/06/84 1942 23 2.5 N 156 18.1 W 19 7 05/07/84 130 23 23.5 N 155 55.7 W 4194 23 8 05/07/84 818 23 45.0 N 155 38.4 W 4340 16 9 05/07/84 1436 24 6.0 N 155 21.0 W 4364 23 10 05/07/84 2042 24 28.0 N 155 3.6 W 3128 17 11 05/08/84 306 24 48.3 N 154 37.8 W 5144 23 12 05/08/84 800 25 11.0 N 154 28.6 W 4990 17 13 05/08/84 1500 25 32.5 N 154 11.0 W 5266 23 14 05/08/84 2042 25 54.0 N 153 53.4 W 5400 18 15 05/09/84 300 26 15.5 N 153 35.7 W 5382 24 16 05/09/84 854 26 36.4 N 153 16.4 W 5322 17 17 05/09/84 1454 26 59.2 N 152 57.7 W 5493 24 18 05/09/84 2054 27 20.0 N 152 41.9 W 5379 18 19 05/10/84 242 27 41.6 N 152 23.6 W 5513 23 20 05/10/84 1024 28 21.3 N 152 0.4 W 5482 17 21 05/11/84 224 28 1.9 N 152 6.0 W 5544 23 22 05/11/84 942 28 42.5 N 152 0.3 W 5602 24 23 05/12/84 1312 29 2.8 N 152 0.1 W 5611 17 24 05/12/84 2036 29 21.3 N 151 59.8 W 5363 24 25 05/13/84 324 29 43.8 N 152 0.8 W 5586 17 26 05/13/84 918 30 4.6 N 152 0.8 W 5317 24 27 05/13/84 1524 30 26.4 N 152 0.3 W 5312 17 28 05/13/84 2124 30 47.5 N 152 0.0 W 5435 24 29 05/14/84 524 31 8.9 N 152 0.0 W 5420 17 30 05/14/84 1112 31 29.8 N 152 0.7 W 5458 24 31 05/14/84 1718 31 50.3 N 151 59.2 W 5219 17 32 05/14/84 2306 32 12.3 N 152 0.4 W 5293 23 33 05/15/84 530 32 32.8 N 152 0.6 W 5229 17 34 05/15/84 1212 32 54.3 N 152 2.7 W 5503 24 35 05/15/84 1854 33 14.4 N 152 0.6 W 5456 17 36 05/16/84 124 33 35.2 N 151 59.6 W 5461 24 37 05/16/84 736 33 56.5 N 151 59.8 W 5015 17 38 05/16/84 1418 34 18.4 N 152 0.1 W 5687 24 39 05/16/84 2048 34 39.3 N 151 59.8 W 5663 17 40 05/17/84 324 35 0.0 N 151 59.2 W 5722 24 41 05/17/84 942 35 20.7 N 151 59.5 W 5798 17 42 05/17/84 1630 35 42.6 N 151 59.9 W 5611 24 43 05/17/84 2254 36 3.2 N 151 59.8 W 5529 17 44 05/18/84 542 36 24.8 N 151 59.5 W 5374 24 45 05/18/84 1600 36 46.2 N 151 59.9 W 5528 17 46 05/18/84 2224 37 6.5 N 151 58.8 W 5539 24 47 05/19/84 436 37 27.1 N 152 0.7 W 5565 17 48 05/19/84 1036 37 48.0 N 152 0.4 W 5886 24 49 05/19/84 1642 38 8.8 N 151 59.2 W 4936 17 50 05/19/84 2224 38 30.3 N 152 0.3 W 5255 24 51 05/19/84 430 38 50.9 N 151 59.1 W 5358 17 52 05/20/84 1042 39 14.3 N 151 59.2 W 5503 22 53 05/20/84 1724 39 33.3 N 152 0.4 W 5157 16 54 05/21/84 418 39 52.9 N 151 59.8 W 5606 24 55 05/21/84 1118 40 15.2 N 152 0.3 W 4885 14 56 05/22/84 736 40 37.4 N 151 59.0 W 4993 24 57 05/22/84 1424 41 6.8 N 151 59.5 W 4959 24 58 05/23/84 706 41 59.1 N 152 3.0 W 5103 24 59 05/23/84 1254 41 38.9 N 151 59.7 W 5090 17 60 05/24/84 948 42 27.6 N 151 59.5 W 5111 17 61 05/24/84 1624 42 55.2 N 151 58.8 W 5149 24 62 05/24/84 2348 43 23.0 N 152 0.4 W 4762 17 63 05/25/84 618 43 49.7 N 151 59.4 W 5689 24 64 05/25/84 1212 44 17.6 N 152 1.0 W 5096 17 65 05/25/84 1724 44 45.3 N 152 0.0 W 5305 24 66 05/25/84 2312 45 12.6 N 151 59.8 W 5298 17 67 05/26/84 518 45 39.9 N 152 0.6 W 5374 24 68 05/26/84 1118 46 7.3 N 151 59.9 W 5322 17 69 05/26/84 1730 46 34.7 N 151 59.0 W 4854 24 70 05/26/84 2348 47 2.3 N 151 59.6 W 5206 17 71 05/27/84 554 47 34.2 N 151 59.8 W 5009 24 73 05/27/84 1206 47 57.9 N 151 59.7 W 4849 17 74 05/27/84 1924 48 25.0 N 151 59.0 W 5019 24 75 05/28/84 254 48 52.2 N 152 0.1 W 4058 17 76 05/28/84 900 49 19.7 N 151 59.4 W 4996 24 77 05/28/84 1524 49 47.8 N 152 1.1 W 4897 17 78 05/28/84 2124 50 15.1 N 151 59.0 W 5110 24 79 05/29/84 418 50 42.4 N 152 0.7 W 4993 16 80 05/29/84 1012 51 9.7 N 152 0.0 W 4781 24 81 05/29/84 1648 51 40.9 N 151 59.4 W 4695 16 82 05/29/84 2324 52 4.7 N 151 58.2 W 496 24 83 05/30/84 530 52 32.0 N 152 0.6 W 4467 17 84 05/30/84 1136 52 59.9 N 151 59.4 W 4448 24 85 05/30/84 1948 53 20.5 N 151 58.9 W 4531 24 86 05/31/84 212 53 41.1 N 151 58.9 W 4846 24 87 05/31/84 842 54 0.5 N 151 56.1 W 4572 24 88 05/31/84 1530 54 23.1 N 151 57.8 W 4156 24 89 05/31/84 2218 54 40.2 N 152 5.3 W 4316 24 90 06/01/84 518 54 57.4 N 152 23.9 W 4127 24 91 06/01/84 1218 55 13.9 N 152 31.5 W 4451 24 92 06/01/84 1900 55 25.6 N 152 38.1 W 5155 24 93 06/02/84 154 55 35.9 N 152 46.3 W 5377 24 94 06/02/84 806 55 46.6 N 152 53.0 W 4405 24 95 06/02/84 1336 55 56.3 N 152 57.6 W 2665 23 96 06/02/84 1824 56 4.0 N 153 2.7 W 1801 18 97 06/02/84 2242 56 12.0 N 153 7.7 W 1340 15 98 06/03/84 218 56 18.0 N 153 12.4 W 303 8 CCHDO Data Processing Notes Date LastName Data Type Event Summary -------- ---------- ----------- -------------- --------------------------------------- 11/13/03 Sanborn SUM Update Needed Time & lat/long changes Stn 7: hour/min is wrong for EN Time should be 0405 Stn 28: hour/min is wrong for BE Time should be 1938 Stn 43: long. should probably be 159 Longitude should be 151 11/26/03 Sanborn BTL/SUM Reformatted May still need QC I did convert it, the bottle data, to WOCE format. I sent Lynne a *.sea and *.sum file. I wanted to do a little fine-tuning on it, not data changes, but more likely quality code consistency. 01/07/04 Anderson CTD/BTL/SUM Data Updated: Data & formatting corrections .sum Corrected time for sta. 7, EN. Had 4050 changed to 0405. (See Sandborn, 11/13/03). Corrected time for sta. 28, BE. Had 2938 changed to 1938. (See Sandborn, 11/13/03). Corrected longitude for sta. 43. Had 159 changed to 151. (See Sandborn, 11/13/03). Stations 28, 32, 43, 46, 50, 54, 62, 66, 70, and 82 are stations that start on one day and end the next day after midnight. All of these stations had the wrong day for EN, I changed them to the correct day. Station 36 had the day for BE as 16 and it should have been 15. I changed it to 15. Station 45 has a time of 0000 for BE, BO, and EN, I left it that way. Station 51 had the day for BE, BO, and EN as 19. It should have been 20, so I changed it to 20. Station 89 had the month as 05 and the day as 31 for EN. It should have been month 06 and day 01, so I changed it. Removed CR's from end of lines. Some adding and deleting of spaces to make file conform to the WHP format. .sea Removed the Q1 and Q2 flags for REVPRS and REVTMP and eliminated the *'s under those parameters. .ctd The ctd's were all in one file. Broke the file into individual stations, and added headers. There were no Q1 flags, so I put 9 for all the -9.0 values and 2 for all the other values. In order to get sta. 3 and sta. 6 converted to exchange I had to put a bogus bottom UNC DEPTH in the .sum file. This was only used for the conversion to exchange. Date LastName Data Type Event Summary -------- ---------- ----------- -------------- -------------------------------------- 01/13/04 Bartolacci CTD/BTL Website Updated: Files online w/ netCDF btl file errors Upon conversion to netcdf, the exchange CTD files were opened to find one more .csv CTD file than original woce ctd files. I've been trying to figure out why the exchange conversion generated a file with no station number but have been unsuccessful. It has valid data in it that belongs to station 3 but no header information. However, station 3 also has a normal .csv file generated as well. This problem remains unsolved at this time. I've renamed the CTD files to indicate the correct directory name and they converted to netCDF fine (no extra files were generated). Bottle file converted to netCDF, but nitrite values are getting listed as blanks (even though the original and csv files have values). This is also unclear at this time and there are no format checking tools for netCDF at this time. All files have been put online, however the errors with the netCDF bottle file are still present. 01/29/04 Bartolacci Cruise ID Website Updated: Public. Was pr16_00a, nowp16_1984a This cruise has been relabeled from pr16_00a to p16_1984a. All files have been renamed and/or remade to reflect this change. This cruise's data has been moved from the repeat data area to the new co2clivar data directories. All original files and notes regarding reformatting and other issues have been moved also. This cruise will not link to the public site until the change to the information has been entered into the database and the new web page has been made public. 03/29/04 Anderson TRITUM Data Update Qual flags set to 2 Merged the TRITUM and TRITER data I got from Lynne Talley into file p16_1984ahy.txt (Marathon II). There were no QUALT flags, so I set the Q1 and Q2 flags for TRITUM to 2. The files for this line still need to be linked. 03/30/04 Anderson DELHE3 Data Update Changed Q flags Changed Q1 and Q2 flage for DELHE3 at sta. 56, bottle 128 from 2 to 3 re email from Lynne Talley (below). Date: Mon, 29 Mar 2004 23:41:42 -0800 (PST) From: Lynne Talley To: lynne@gyre.ucsd.edu, sharon@gyre.ucsd.edu, whpo@ucsd.edu Subject: p13 delhe3 flag sta 56 Sarilee - on P13, when the helium value at sta. 56, bottle 128, was flagged as "3", the DELHE3 value should also have been flagged as "3". 06/19/05 Talley Cruise Report Submitted scan of hard copy Here are the first 19 pages of the data report from the 1984 occupation of P16. I will send over a copy for Kristin to keep in her files. The report includes a data listing for each station and a set of profiles for each station, which we have not scanned in.