John M. Morrison -- 18 July 1996

TN054:  JGOFS Arabian Sea Process Study -- Process Cruise #7:

This "readme" file pertains to the CTD data taken
during RV T.G.  Thompson cruise TN054.  This cruise was the
seventh JGOFS Arabian Sea Process Leg and took place during November -
December 1995. Wilford Gardner of Texas A&M University
(wgardner@astra.tamu.edu) was the chief scientist.

Dissolved oxygen, ransmissometer and fluorometer data
were also collected on the CTD, but are not reported here
as we have not calibrated this data.


The raw data files may be requested from:

        DR.JOHN M. MORRISON
        NORTH CAROLINA STATE UNIVERSITY
        DEPARTMENT OF MARINE, EARTH AND ATMOSPHERIC SCIENCES
        JORDAN HALL RM. 1125
        BOX 8208
        RALEIGH, NC 27695-8208


CTD Calibration:

On this cruise, one CTD configurations was used.  The processing
and calibration information for this configuration are given
below:

John M. Morrison -- 25 June 1996

This the setup, processing and calibation information for 
the CTD for cruise TN054.

Sea-Bird Processing Information:  Example from 05400101.cnv

* Sea-Bird SBE 9 Raw Data File:
* FileName = G:\05400101.DAT
* Software Version 4.205
* Temperature SN = 748
* Conductivity SN = 399
* Number of Bytes Per Scan = 37
* Number of Voltage Words = 4
* System UpLoad Time = Nov 30 1995 14:21:11
* NMEA Latitude = 22 23.63 N
* NMEA Longitude = 059 53.76 E
* NMEA UpLoad Time = not available
* Store Lat/Lon Data = Add to Header and Append to Every Scan
* Ship: R/V Thomas G. Thompson
* Cruise: Process 7
*         TNO54
# nquan = 19
# nvalues = 503
# units = metric
# name 0 = t068: temperature, pri, IPTS-68 [deg C]
# name 1 = c0mS/cm: conductivity, primary [mS/cm]
# name 2 = pr: pressure [db]
# name 3 = t168: temperature, sec, IPTS-68 [deg C]
# name 4 = c1mS/cm: conductivity, secondary [mS/cm]
# name 5 = oxML/L: oxygen [ml/l]
# name 6 = xmiss: transmissometer
# name 7 = flS: fluorometer, sea tech
# name 8 = par: irradiance (PAR)
# name 9 = depS: depth, salt water [m]
# name 10 = potemp068: potential temperature, pri, IPTS-68 [deg C]
# name 11 = potemp168: potential temperature, sec, IPTS-68 [deg C]
# name 12 = sigma-é00: density, sigma-theta [kg/m^3], T0, C0
# name 13 = sigma-é11: density, sigma-theta [kg/m^3], T1, C1
# name 14 = sigma-t00: density, sigma-t [kg/m^3], T0, C0
# name 15 = sigma-t11: density, sigma-t [kg/m^3], T1, C1
# name 16 = sal00: salinity, PSS-78 [PSU], T0, C0
# name 17 = sal11: salinity, PSS-78 [PSU], T1, C1
# name 18 = flag:  0.000e+00
# span 0 = 18.8945, 25.8147
# span 1 = 48.824211, 56.414886
# span 2 = 1.000, 253.000
# span 3 = 18.9094, 25.8291
# span 4 = 48.669849, 56.184273
# span 5 = 0.02782, 4.02865
# span 6 = 70.12, 75.55
# span 7 = 1.838e-01, 2.645e+00
# span 8 = 4.596e+01, 4.596e+01
# span 9 = 0.994, 251.263
# span 10 = 18.8496, 25.8100
# span 11 = 18.8645, 25.8262
# span 12 = 24.4696, 26.3310
# span 13 = 24.3274, 26.2107
# span 14 = 24.4683, 26.3193
# span 15 = 24.3264, 26.1990
# span 16 = 36.1896, 36.8264
# span 17 = 36.0339, 36.6447
# span 18 = 0.000e+00, 0.000e+00
# interval = decibars: 1
# start_time = Nov 30 1995 14:21:11
# bad_flag = -9.990e-29
# serial_numbers = t0:748, c0:399, pr:34901, t1:761, c1:478, ox:352,
stLs6000:241, xmiss:156D, flS:84D, par:7175
# datcnv_date = Dec 01 1995 21:17:17, 4.205
# datcnv_in = 05400101.DAT CTD_24.CON 748 399 34901
# datcnv_skipover = 0
# wildedit_date = Dec 01 1995 21:19:58, 4.205
# wildedit_in = 05400101.CNV
# wildedit_pass1_nstd = 2.0
# wildedit_pass2_nstd = 20.0
# wildedit_npoint = 100
# wildedit_vars = t068 c0mS/cm pr t168 c1mS/cm oxML/L xmiss flS par
# wildedit_excl_bad_scans = yes
# celltm_date = Dec 01 1995 21:20:59, 4.205
# celltm_in = TEMP.CNV
# celltm_alpha = 0.0300, 0.0000
# celltm_tau = 9.0000, 0.0000
# filter_date = Dec 01 1995 21:21:51, 4.205
# filter_in = 05400101.CNV
# filter_low_pass_tc_A = 0.150
# filter_low_pass_tc_B = 0.100
# filter_low_pass_A_vars = pr
# filter_low_pass_B_vars =
# loopedit_date = Dec 01 1995 21:23:41, 4.205
# loopedit_in = TEMP.CNV
# loopedit_minVelocity = 0.000
# loopedit_excl_bad_scans = yes
# binavg_date = Dec 01 1995 21:24:54, 4.205
# binavg_in = 05400101.CNV
# binavg_bintype = Pressure Bins
# binavg_binsize = 1.00
# binavg_excl_bad_scans = yes
# binavg_downcast_only = no
# binavg_skipover = 0
# binavg_surface_bin = yes, min = 0.500, max = 0.500, value = 0.000
# derive_date = Dec 01 1995 21:25:49, 4.205
# derive_in = TEMP.CNV CTD_24.CON
# file_type = ascii
*END*

The same salinity correction has been applied for all of the stations on
Cruise TN054. 

Corrected CTD Salinity = Observed CTD Salinity - Sal Correction (Defined
Below)


MINIMUM DEPTH USED =       500.000
MAXIMUM DEPTH USED =       4492.80

Sal Correction = -0.008

Standard Deviation = +/- .002


In order to minimize the effects of the large salinity differences
between the CTD and Bottles that occured because the
CTD sensors were actually sampling waters that were different from
those collected in the Nisken Bottles in the high-gradient, variable
surface layers, the final calibration was performed using differences
for samples collected at depths greater than 500 meters.

MINIMUM DEPTH USED =       000.000
MAXIMUM DEPTH USED =       500.000

In addition, if a filter of +/- .025 is applied to the differences
between the CTD and Bottle Salinities in the high-gradient, variable
surface layers, and the full depth range is used, the mean shifts 
slightly to -.011+/-.005; which is still within the standard deviation
of the fit using the differences from depths greater than 500 meters.

Therefore, a salinity correction of -.011 was used for depths less
than 500 meters and a correction of -.008 was used for depths greater
than 500 meters.

The reported Conductivities and Salinities are good to +/- .002.