


     GP8-03-KA
     NOAA Ship KA'IMIMOANA
     Kwajalein, Marshall Islands - Honolulu, HI
     November 17 - December 13, 2003

     Chief Scientist: Linda Stratton
     Survey Department: ST Lillian Stuart
     CTD Personnel: ST Lillian Stuart, Karen Taylor
     Final Processing: K. McTaggart


     ACQUISITION: 

     Fifty CTD profiles were collected during this cruise.  Twenty-three
     profiles were collected from 8N to 8S along 165E.  Twenty-seven profiles
     were collected from 8S to 8N along 180, and along the ship's trackline
     to 12N.  The majority of casts were to 1000m.  Four casts were deep (>2300m)
     and one was to 1600m.

     PMC's Sea-Bird 9plus CTD s/n 09P13807-0439 measuring pressure (s/n 
     59788), temperature sensors s/n 4211 (TAO) and s/n 2126 (PMC) and conduc-
     tivity sensors s/n 303 and s/n 1537 (both PMC) were used for all casts.  

     The CTD was mounted in the TAO spare custom 24-bottle frame with SBE 
     carousel pylon s/n 88.  The CTD data stream was passed through 11plus
     deck unit s/n 376 with factory settings.  Digitized data were sent
     to a Dell personal computer using Windows 98 OS equipped with Sea-Bird's
     SEASOFT Windows acquisition software.  Calibrated data were displayed
     in fixed listing and graphical form in real-time, as well as stored in
     raw form onto hard disk.  Backups of the raw data were made on Zip disk,
     CD, and DVD.   CD and DVD were returned to PMEL for post-cruise processing.


     SALINITIES:
   
     No duplicate samples were taken this cruise.  Salinity analysis was performed
     using Guildline Autosal 8400B salinometer s/n 61.667, OSI ACI2000 interface,
     and IAPSO standard seawater batch #P141 dated June, 2002.  Bath temperature
     was set to 24 degrees Celsius.  Raw data were archived on the CTD data CD 
     and returned to PMEL.

     One run containing station 6 and 7 samples had a bad standardization.  Samples
     from these two stations were not used in calibrations.

     At PMEL, ACI2000 .dat files were ammended in Excel such that only 1 header
     line, 1 standard correction line, and 3 salinity lines per sample were
     included in the file.  Corrected salinity values were fixed to 4 decimal
     places and the file overwritten in the NT folder as a space delimited file.


     POST-CRUISE CONDUCTIVITY CALIBRATIONS:
   
     GP803s.cal2 of secondary sensor data (te 2126, co 1537) was created at PMEL and
     used to calibrate stations 1-50.  Primary conductivity sensor 303 continues to
     read low by 0.02 mS/cm in the top 200m (owing to bad or outdated or mistyped
     coefficients) and was not chosen for final calibration.  

     Final pressure and temperature calibrations were pre-cruise.  A viscous
     heating correction of -0.0006 C was applied to temperature sensors s/n 2126
     and s/n 4211 but no historical data for a drift correction are available for
     either sensor.

     For conductivity 1537, stations 1-50, CALCOS0 was used to determine the best fit:

       [sta,slope,bias,newbotco,newctdco]=calcos0(stat,cond,pres,botc,2.8,1,50);
       number of points used   459
       total number of points  567
       % of points used in fit 80.95
       fit standard deviation  0.002943
       fit bias                -0.015357053
       min fit slope           1.0004159
       max fit slope           1.0004159

     Slope and bias correction values were applied to CTD burst data and converted
     directly into netCDF format using CALMSTR and CLB_EPS.


     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 if a Sea-Bird rosette sampler was used.  Both down and up casts
     are processed.

     ROSSUM averages the bottle data specified in the DATCNV output and 
     derives salinity, theta, sigma-t, and sigma-th. Bottle data are used
     to calibrate the CTD post-cruise. 

     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.

     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.  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.

     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.

     DERIVE uses 1 db averaged pressure, temperature, and conductivity to
     compute salinity, theta, sigma-t, sigma-th, and dynamic height.

     TRANS converts the data file from binary to ASCII format.

     Program CNV_EPS2 applies post-cruise secondary temperature corrections and
     conductivity calibration coefficients, as well as an offset to salinity,
     recomputes the derived variables in DERIVE, and converts the ASCII data
     files to netCDF format.  CNV_EPS2 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_EPS2
     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 '888'; when interpolated over greater than 2 db, the
     WOCE quality word is '666'.  The WOCE quality word consists of a 1-digit
     flag for pressure, temperature (ITS-90), and salinity.

     Bad salinities were flagged in *_eps.clb files and omitted from the .nc
     bottle data files: 
	station 0031 sample 105
	station 0131 sample 109
	station 0211 sample 104
	station 0381 sample 104
	station 0461 sample 108
	station 0471 sample 109
	station 0481 sample 109 

     Final CTD and bottle files were moved to /home/plover/insitu2/DATA/hayes
     /gp803/ctd/ and included in the MySQL data management tables on January
     26, 2004.
