



     GP8-05-KA
     NOAA Ship KA'IMIMOANA
     Kwajalein, Marshall Islands - Honolulu, HI
     November 27 - December 21, 2005

     Chief Scientist: Kristy McTaggart
     Survey Department: ST Karen Taylor
     CTD Personnel: ST Karen Taylor
     Final Processing: Kristy McTaggart


     ACQUISITION:

     Only 15 CTD profiles were collected at 15 stations during this cruise.
     Ten profiles were collected from 8N to 2S along 165E, two profiles 
     were collected at 2S and 5S along 180, one at 8S, 180, and along 155W at 
     8S and 2N.  The majority of casts were to 1000m, and only 3 casts were 
     deep (>3000m).

     The unusual trackline and abbreviated CTD stations on this cruise was due
     to a failure in the A-frame hydrolics during GP705, and the ship returned
     to Honolulu for 10 days of repairs.  Four lines were then combined and 
     split between GP705 leg 2 and GP805.

     PMC's Sea-Bird 9plus CTD s/n 09P13807-0439 (pressure s/n 59788) was used
     for all casts during this cruise, along with primary temp sensor s/n 1710 
     and primary cond sensors s/n 354 (casts 1-8) and 1537 (casts 9-15), and 
     secondary temp sensor s/n 4211 and secondary cond sensor s/n 1467. There
     were also the same three optical sensors on the package as GP705.  The
     fourth sensor (OSU PAR) was removed after GP505. 
     
     The CTD was mounted in the TAO spare custom 24-bottle frame with TAO SBE 
     carousel pylon s/n 54.  The CTD data stream was passed through TAO 
     11plus deck unit s/n 376 with factory settings.  Digitized data were sent
     to a new Dell personal computer using Windows XP OS equipped with SBE'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 a Sony thumb
     drive and DVD.   DVDs were returned to PMEL for post-cruise processing.


     SALINITY SAMPLES:
   
     Salinity analysis was performed using Guildline Autosal 8400B salinometer 
     s/n 61.667, Ocean Scientific ACI2000, and IAPSO standard seawater batch #P145
     dated July 2004.  The bath temperature was set to 24 degrees Celsius.  Eight
     samples are collected per whole-degree cast.  Raw data were archived along 
     with CTD data on DVD.  

     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.

     No samples were collected from casts 0151 per the Chief Scientist.  The first
     run had a bad standardization and casts 1-3 were not used for calibrations.


     CONDUCTIVITY CALIBRATION:
   
     GP805S.CAL of primary sensor data (te 1710, co 354, co 1537) was created   
     and used to calibrate stations 1-9 and 10-15, respectively.

     Final pressure and temperature calibrations were pre-cruise.  A viscous
     heating correction of -0.0006 C was applied to the temperature sensor.
     The drift correction for s/n 1710 was +0.000173.

     The best results for sensor 354 for casts 1-9 were from CALCOS1.  The fit
     standardization is large as the sensor was heavily fouled.

     number of points used   41
     total number of points  45
     % of points used in fit 91.11
     fit standard deviation  0.005088
     fit bias                -0.021864062
     min fit slope           1.0011832
     max fit slope           1.0013698

     The best results for fresh sensor 1537 for casts 10-15 were from CALCOS0:

     number of points used   35
     total number of points  39
     % of points used in fit 89.74
     fit standard deviation  0.002557
     fit bias                -0.00082058934
     min fit slope           0.99996233
     max fit slope           0.99996233
     
     Slope and bias correction values were applied to CTD burst data using 
     CALMSTR.  Calibrated data were converted into NetCDF format using CLB_EPS 
     on PC Pacific.  Final calibrations were applied to profile data and
     converted into NetCDF format using CNV_EPS1.


     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, and sigma-theta. Bottle data are used
     to calibrate the CTD and O2 sensor 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.  Data were kept within 100
     of the mean (i.e. all data).

     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.
 
     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.  There is no surface bin.

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

     TRANS converts the data file from binary to ASCII format.

     Program CNV_EPS1 applies post-cruise temperature corrections and
     conductivity calibration coefficients, as well as any offset to salinity,
     recomputes the derived variables in DERIVE, and converts the ASCII data
     files to netCDF format.  CNV_EPS1 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_EPS1
     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.

     There were no bad bottle salinities.

     Final CTD and bottle files were moved to /home/plover/insitu2/DATA/hayes
     /gp805/ctd/ and /bot and included in the MySQL data management tables on
     January 18, 2006.
