US JGOFS Antarctic Environments Southern Ocean Process Study (AESOPS) Revelle Leg KIWI06, APFZ Survey 1, October - November 1997 Documentation for: The Trace Metal Rosette Hydrographic bottle data L.A. Codispoti (lou@ccpo.odu.edu) Old Dominion University, October 1998 General Comments: This "readme" file pertains to the salinity, and nutrient data taken from 30 liter Go-Flo sampling bottles on the trace metal rosette employed during the AESOPS Survey I leg on board the R/V Roger Revelle (RR06). CTD salinity and temperature data taken when the bottles were tripped are also included. Dr. Tim Cowles of the College of Oceanic and Atmospheric Sciences at Oregon State University (cowles@oce.orst.edu) was the chief scientist during this leg. This cruise was the first survey leg on the R/V Roger Revelle during the U.S. JGOFS program in the Southern Ocean (AESOPS). The Revelle legs focused on the Polar Front region and complemented several AESOPS cruises on board the R/V Nathaniel Palmer which focused on the Ross Sea. The trace metal clean rosette equipped with 8, 30-l Go-Flo bottles was lost on 13 November. Bottle data taken throughout the cruise with the hydrographic rosette equipped with 24, 10 liter Bullister bottles have been submitted to the U.S. JGOFS data base in a separate file. The trace metal and hydrographic rosette data are in different files because the CTD data from the hydrographic rosette are of a higher quality than the CTD data from the trace metal rosette which was equipped with a Sea-Bird SBE-19 Seacat CTD, and because Go-Flo bottles while superior for obtaining "trace metal clean" samples are not as likely to produce as high quality hydrographic data as the Bullister bottles. Additional hydrographic data were collected by other research teams, and will be submitted to the data base by these groups. These additional observations included observations from towed undulating devices and from trace metal clean bottle casts made by hanging bottles on Kevlar cable. Investigators interested in these data can find out about their status by consulting the chief scientist. Some questionable data are not included in this report. These data are available upon request. No units are given for salinity in this report because the most recent definitions of salinity define it as a dimensionless number. To accommodate every preference, Winkler oxygen values are reported in ml/l, micromolar and micromoles per kg. The latter values can only be calculated with a knowledge of the oxygen sample temperatures when the samples were drawn. These "draw temperatures" are not reported here, but can be obtained by contacting lou@ccpo.odu.edu. Nutrient values are reported in micromolar. They can be converted to micromoles per kg, by combining laboratory temperature on the Revelle (approx. 21 deg C ) and the salinity of the sample to compute density and then dividing the value in micromolar by this number. Methods: In general, the methods employed for the bottle salinity, and nutrient analyses did not differ significantly from those described in the JGOFS protocols that were distributed in 1994 (UNESCO, IOC Manual and Guide #29). Minor differences included the following: 1) The protocols give one a choice of adjusting nutrient methods so that calibration curves are strictly linear, or opting for more response and taking into account non-linearities. We choose the latter method. 2) No corrections were made for "carryover" between nutrient samples run on the Technicon Autoanalyzer. Carryover effects in our nutrient analyses are generally less than ~2% of the concentration difference between adjacent samples, and were minimized by arranging samples in depth order, etc. 3) Calibration and re-calibration of volumetric ware were not exactly as described in the JGOFS protocols, but all volumetric flasks, maxipettors, and dosimats were calibrated. 4)Duplicate oxygen samples were not routinely drawn. 5) The JGOFS protocols do not describe an automated technique for the analysis of ammonium concentrations. We employed the Berthelot reaction using a method somewhat similar to the method described by Whitledge et al. (1981, Whitledge, T.E., Malloy, S.C., Patton, C.J. and Wirick, C.D. Automated Nutrient Analyses in Seawater. Brookhaven National Laboratory Rept. BNL 51398, 216pp.). Temperature: The temperature data associated with each bottle depth were taken by the CTD system during the bottle tripping process. Consult the companion CTD data report for this cruise to learn more about the CTD system. As noted above, the CTD system on the trace metal rosette was not designed to produce data of as high a quality as those produced by the CTD system on the hydrographic rosette. Sampling: The samples in this report were taken from ~30 liter Go-Flo bottles. Because there is little or no lag time between triggering a bottle and bottle closure, our sampling protocols request that bottles be held at the sampling depth for at least 30 seconds before tripping. Note that the mid-point of the Go-Flo bottles was about 0.5 meter above the CTD sensor. No attempts were made to correct for this. Salinity: Bottle salinities were determined with Guildline Autosal salinometers. New vials of standard sea-water were used to standardize before and at the end of every run. Agreement between bottle salinities and the Seacat CTD sensor on the trace metal rosette was usually better than 0.02 before post-cruise data processing which employs the bottle salinities to correct the CTD salinities. More information on the quality of the salinity data are given in the companion CTD report. Dissolved oxygen: The Winkler dissolved oxygen apparatus was built and supplied by the SIO/ODF group. This system is computer controlled and detects the end-point photometrically. Temperatures of the thiosulfate and standard solutions are automatically monitored by this system. Nutrients: Note that the terminology used to describe nutrients has become somewhat loose over the years and that silicate = silicic acid, dissolved silicon or reactive silicate, and phosphate = reactive phosphorus. Nutrient analyses were performed on a 5-channel Technicon II AA system that was modified and provided by Doug Masten (doug@odf.ucsd.edu) of the ODF group at the Scripps Institution of Oceanography. Queries: Questions about these data may be addressed to: Dr. L. A. Codispoti CCPO Old Dominion University Norfolk, VA 23529 lou@ccpo.odu.edu