     GP7-00-KA
     NOAA Ship Ronald H. Brown
     San Diego, CA - Rodman, Panama
     October 17 - November 16, 2000

     Chief Scientist: Mr. Rick Miller
     Survey Department: CST Jonathan Shannahoff
     CTD Personnel: J. Shannahoff, Brian Lake
     Final Processing: K. McTaggart


     ACQUISITION: 

     Forty-nine CTD profiles were collected on this cruise.  Twenty-one
     profiles were collected along 110W from 8N to 8S, and 27 profiles were
     collected along 95W from 8S to 12N.  One test cast was performed prior
     to reaching the 110W line where 24 bottles were fired at depth but no
     samples were drawn for salinity analysis and the profile data were not
     processed.  The majority of casts were to 1000 m, 16 were deep (>2900 m).
     Four additional casts were made for the purpose of calibrating the TC
     modules from the TAO moorings (0212, 0292, 0412, and 0481).  These data
     were processed and used by Brian Lake, and are not part of this data set.

     PMEL's Sea-Bird 9plus CTD s/n 09P8431-0315 measuring pressure (s/n 
     53960), temperature sensors (s/n 1370, 1455), and conductivity sensors 
     (s/n 1180, 1177) were used for all casts (TAO2.CON).
     The CTD was mounted in a custom 24-bottle frame with Sea-Bird rosette 
     sampler s/n 163.  The CTD data stream was passed through Sea-Bird 11plus
     deck unit s/n 314 with factory settings.  An analog signal was recorded 
     onto the audio portion of VCR tape as a backup.  Digitized data were sent
     to the ship's Gateway G6-200 personal computer equipped with Sea-Bird's 
     SEASAVE for Windows acquisition software (Win32 v1.10) where calibrated 
     data were displayed in graphical form in real-time, as well as stored in
     raw form onto hard disk.  Backups of the raw data were made on Zip disks
     and CD-ROM and returned to PMEL for post-cruise processing. 

     Termination problems were evident at the start of the cruise.  The sea
     cable was reterminated twice, after casts 12 and 13, by the ship's ET.
     Spiking problems continued intermittently throughout the cruise.  Ship
     suspects a problem in the sea cable at around 3000 meters.  They may chose
     to cut off 3000 meters of cable during the winter inport, leaving 7000 
     meters for future cruises.


     SALINITIES:

     Seawater was collected at 12 depths each cast and salinity samples drawn.
     Two salinity samples were taken from the deepest Nisken.  Duplicate samples
     were analyzed on a subsequent day from the rest.  Salinity analysis was
     performed using a Guildline Autosal 8400B salinometer s/n 60.843.  IAPSO 
     standard seawater batch #P136 dated April, 1999, was used for all casts. 


     OXYGENS:

     A SBE 43 prototype oxygen sensor was mounted on the primary underwater
     package and plumbed with the primary TC pair.  Sample oxygen concentrations
     were made using the Winkler titration method by Melissa Hendricks of 
     Princeton University.


     POST-CRUISE CONDUCTIVITY CALIBRATIONS:

     GP700S.CAL of primary (s/n 1370, 1180) sensor data (not including any
     duplicate salts) was created at the lab post-cruise.

     Final pressure and temperature (s/n 1370) calibrations were pre-cruise.
     A drift correction of 0.000319 C and a viscous correction of -0.0006 C 
     were applied to temperature.  Conductivity fit coefficients were determined
     using Matlab program CALCOP0:

                        number of points used   322
                        total number of points  393
                        % of points used in fit 81.93
                        fit standard deviation  0.001516
                        fit bias                1.1184738e-002
			fit co pressure fudge   7.2296087e-007
                        min fit slope           1.0004229
                        max fit slope           1.0004229

     Slope, bias, and pressure correction values were applied to CTD data 
     and converted directly into netCDF format using GP7_CNV_EPS; and to bottle
     file data using GP7_CALMSTR and GP7_CLB_EPS. 


     POST-CRUISE OXYGEN CALIBRATIONS:

     Ninety-one sample oxygen values and associated upcast CTD burst data from
     .BTL files made up the oxygen calibration file (.CLO).  OXFITMR was used
     to determine coefficients for slope, bias, and lag.  Because this new
     sensor is temperature compensated, tcor and weight were fixed.  And because
     there were no sample data below 1000 m, pcor was also fixed.  After four
     iterations, the following were the result of fitting 85 points:
			
			bias	0.007
		       slope    0.5056e-03
			Pcor 	0.1500e-03
			Tcor   -0.1000e-03
			  Wt    0.0000
			 Lag   -0.1174e+01

     Oxygen coefficients were applied to burst data using GP7_CALMSTR and 
     GP7_CLB_EPS, and to profile data using GP7_CNV_EPS.  Data were truncated
     at 1000 dbar as the fit did not appear reliable beyond that.  Up/down
     profiles with bottle oxygens overlaid were examined.  Co-located profiles
     with P18 stations showed the goodness of the fit.


     FINAL PROCESSING:

     The following are the standard SEASOFT processing modules used to reduce 
     Sea-Bird CTD data:

     DATCNV converts raw data to engineering units and creates a bottle
     file (.ROS) where scans marked with a bottle confirm bit are averaged
     over the following 2 second interval.

     ALIGNCTD advances secondary conductivity relative to temperature by
     0.73 seconds.  This is the typical net advance of ducted temperature
     and conductivity sensors with a 3000 rpm pump.  The SBE 11plus deck
     unit automatically advances primary conductivity.  ALIGNCTD also
     advances oxygen for this cruise by 8 seconds, according to Jim 
     Carlson of Sea-Bird regarding their prototype SBE-43 oxygen sensor.

     ROSSUM averages the bottle data specified in the DATCNV output and
     derives salinity, theta, sigma-th, and oxygen.

     WILDEDIT makes two passes through the data in 100 scan bins.  The
     first pass flags points greater than 2 standard deviations; the
     seond pass removes points greater than 20 standard deviations from
     the mean with the flagged points excluded.

     FILTER applies a low pass filter to pressure with a time constant of
     0.15 seconds.  In order to produce zero phase (no time shift) the filter
     is first run forward through the file and then run backwards through
     the file.

     CELLTM uses a recursive filter to remove conductivity cell thermal
     mass effects from the measured conductivity.  In areas with steep
     temperature gradients the thermal mass correction is on the order
     of 0.005 psu.  In other areas the correction is negligible.  The
     value used for the thermal anomaly amplitude (alpha) is 0.03.  The
     value used for the thermal anomaly time constant (1/beta) is 7.0.
 
     FILTER applies a low pass filter to pressure with a time constant of
     0.15 seconds, and to conductivity with a time constant of 0.03 seconds.
     In order to produce zero phase (no time shift) the filter is first
     run forward through the file and then run backwards through the file.

     DERIVE1 is used here to compute doxc/dt and oxygen (umol/kg).

     LOOPEDIT removes scans associated with pressure slowdowns and
     reversals.  If the CTD velocity is less than 0.25 m/s or the pressure
     is not greater than the previous maximum scan, the scan is omitted.

     BINAVG averages the data into 1 db bins.  Each bin is centered around
     a whole pressure value, e.g. the 1 db bin averages scans where pressure
     is between 0.5 db and 1.5 db.

     DERIVE2 uses 1 db averaged pressure, temperature, and conductivity to
     compute salinity.

     TRANS converts the data file from binary to ASCII format.

     Program GP7_CNV_EPS applies post-cruise temperature corrections and
     conductivity calibration coefficients, recomputes the derived variables 
     in DERIVE, and converts the ASCII data files to netCDF format.  GP7_CNV_EPS
     skips bad records near the surface (typically the top 3 m) as well as any
     records containing -9.990e-29, and copies back raw data to the surface 
     (0 db) within 10 db.  Because the SBE module LOOPEDIT does not handle 
     package slowdowns and reversals well in the thermocline where gradients 
     are large, CNV_EPS removes raw data records where a sigma-theta 
     inversion is greater than -0.01 kg/m3.  Data are linearly interpolated 
     such that a record exists for every 1 db.  When data are copied back to 
     the surface, the WOCE quality word is '8888'; when interpolated over 
     greater than 2 db, the WOCE quality word is '6666'.  The WOCE quality word
     consists of a 1-digit flag for pressure, temperature (ITS-90), salinity 
     and oxygen.

     Program GP7_CALMSTR applies post-cruise temperature corrections and 
     conductivity calibration coefficients and recomputes the derived variables
     in ROSSUM.  GP7_CLB_EPS converts the ASCII bottle data file into individual
     cast netCDF data files. Station 4 sample 104, station 9 sample 102, and
     stations 32, 43, 47 all sample 113 were flagged as bad.

     Final CTD and bottle files were moved to DISK$EPIC1:[HAYES.DATA.GP700.CTD] 
     and included in the MySQL data management tables on December 27, 2000.

     CTD oxygen values and bottle oxygen values were converted from umol/l to
     umol/kg using programs gp7_fix.f and gp7_fixb.f respectively, on May 21,
     2001.  
