US JGOFS Antarctic Environments Southern Ocean Process Study (AESOPS)

Revelle Leg KIWI08, APFZ Survey 2, 8 January - 8 February 1998

Documentation for: THE HYDROGRAPHIC BOTTLE DATA 


L.A. Codispoti (lou@ccpo.odu.edu)
Old Dominion University,  December, 1998

General Comments:

This "readme" file pertains to the salinity, dissolved oxygen,
and nutrient data taken from sampling bottles with the
hydrographic rosette that was equipped with 24 ~10-liter
"Niskin-like" Bullister bottles made mostly of PVC and equipped
with orange silicone o-rings during Revelle leg RR08 (8 January -
8 February 1998).  Dr. Kenneth H. Coale of the Moss Landing
Marine Laboratories (coale@mlml.calstate.edu) was the chief
scientist during this leg.  This cruise was the second 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 that focused on the Ross Sea.  Several casts
with a trace metal clean rosette equipped with 8, 30-l Go-Flo 
bottles were also taken during this leg. These data are not
reported here because this system was not designed to produce
hydrographic data of "WOCE quality".  They have been submitted in
a companion report.  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. The user should also be
aware that considerable underway hydrographic data were also
collected during this leg and these data are not included in this
report.  

Some questionable data are not included in this report. These
data are available upon request.

-----------------------------------------------------------------
IN PARTICULAR, PLEASE NOTE THAT PROBLEMS WERE ENCOUNTERED WITH
THE AMMONIUM ANALYSIS AT THE BEGINNING OF THIS CRUISE.  THUS, 
AMMONIUM DATA ARE NOT REPORTED UNTIL STATION 4, CAST 3 IN THIS
REPORT AND UNTIL STATION 4, CAST 2 IN THE COMPANION TRACE METAL
ROSETTE DATA REPORT THAT HAS BEEN SUBMITTED TO THE JGOFS DATA
BASE.
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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.  For the laboratory conditions on this leg, the
nutrient values in micromolar can be converted  to micromoles per
kg,  by combining a temperature of 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, Winkler
dissolved oxygen, 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) Sea-Bird CTD
systems and bottle carousels were employed (SBE-9+ underwater
units, SBE-11 deck units, SBE-32 carousels).  These units
represent a newer generation of equipment than the instruments
described in the JGOFS protocols.  2) 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.  3)
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. in some 
cases.  4) 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.  5) 
Duplicate oxygen samples were not routinely drawn.  6) 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. 

Sampling:

The samples in this report were taken from ~10 liter Bullister
bottles.  Because there is little or no lag time between
triggering a bottle and bottle  closure with the Sea-Bird
rosette systems, 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 SAMPLING BOTTLES WAS ~1 METER
ABOVE THE CTD SENSORS.  THE DATA HAVE NOT BEEN CORRECTED FOR THIS
OFFSET. 

Salinity:

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 recently calibrated sensors  on the Sea-Bird CTD systems
was usually better than 0.01 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 Scripps Institution of Oceanography's (SIO) Ocean Data
Facility (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.  ALSO READ THE NOTE REGARDING
PROBLEMS WITH THE INITIAL AMMONIUM RESULTS IN THE "GENERAL
COMMENTS" SECTION ABOVE.

Queries:

Questions about these data may be addressed to:

Dr. L. A. Codispoti
CCPO
Old Dominion University
Norfolk, VA 23529
lou@ccpo.odu.edu