US JGOFS Antarctic Environments Southern Ocean Process Study (AESOPS)
Palmer Leg 97-03; Apr. - May 1997; Process 3
John M. Morrison
26 August 1998
This "readme" file pertains to the CTD data taken
during RV N. B. Palmer cruise NBP9703 from 31 March - 12 May 1997.
Dr. Hugh Ducklow of the Virginia Institute of Marine Sciences
(duck@vims.edu) was the chief scientist during this leg.
This cruise was the third process study leg
of the U.S. JGOFS program in the Southern Ocean (AESOPS).
CTD Calibration:
On this cruise, one CTD configurations was used. The processing
and calibration information for this configuration is given below:
The casts made with the Trace Metal Clean Rosette on this leg are not
reported here because this system was not designed to produce CTD data of
"WOCE" quality. The CTD system on this rosette was not capable of the
precision obtained from the system on the hydrographic rosette. It was
determined that the CTD dissolved oxygen sensor did not produce reliable
data on this cruise. The CTD transmissometer, fluorometer, light scattering
and PAR measurements are currently being calibrated by other investigators.
It should be noted that the original Chelsea fluorometer failed on station
97331001.CNV and was replaced with a Sea Tech fluorometer.
Note: The standard JGOFS CTD numbering scheme was not followed for this
cruise. The scheme used was 97330101.CNV --- CCCSSScc.CNV where CCC is the
cruise designation, SSS is the station designation beginning with station 300,
and cc is the cast number. The station designation should have started with
station 000 and not 300. All of the original data collected aboard ship
use this scheme, but the data in the JGOFS database have been changed to
the standard numbering scheme and start with station 000, cast 01.
This is the setup, processing and calibration information for all of the CTD
casts made with the Primary CTD system for cruise NBP9703.
---------------------------------------------------------------------------
SEA-BIRD Processing Information: Example 97330001.CNV
* Sea-Bird SBE 9 Raw Data File:
* FileName = G:\97300001.DAT
* Software Version 4.218
* Temperature SN = 2299
* Conductivity SN = 1852
* Number of Bytes Per Scan = 30
* Number of Voltage Words = 4
* System UpLoad Time = Apr 08 1997 21:36:18
* NMEA Latitude = 63 30.08 S
* NMEA Longitude = 174 47.79 E
* NMEA UpLoad Time = not available
* Store Lat/Lon Data = Add to Header Only
** Ship: R/V Nathaniel B. Palmer
** Cruise: JGOFS Southern Ocean
# nquan = 19
# nvalues = 1984
# units = metric
# name 0 = scan: scan number
# name 1 = t068: temperature, pri, IPTS-68 [deg C]
# name 2 = t168: temperature, sec, IPTS-68 [deg C]
# name 3 = pr: pressure [db]
# name 4 = c0mS/cm: conductivity, primary [mS/cm]
# name 5 = c1mS/cm: conductivity, secondary [mS/cm]
# name 6 = xmiss: transmissometer
# name 7 = stLs6000: sea tech ls6000 [mg/l]
# name 8 = par: irradiance (PAR)
# name 9 = oxML/L: oxygen [ml/l]
# name 10 = flC: fluorometer, chelsea
# name 11 = depS: depth, salt water [m]
# name 12 = potemp068: potential temperature, pri, IPTS-68 [deg C]
# name 13 = sal00: salinity, PSS-78 [PSU], T0, C0
# name 14 = gpa: geopotential anomaly
# name 15 = dm: dynamic meters
# name 16 = sigma-é00: density, sigma-theta [kg/m^3], T0, C0
# name 17 = sigma-t00: density, sigma-t [kg/m^3], T0, C0
# name 18 = flag: 0.000e+00
# span 0 = 60, 63442
# span 1 = -0.0190, 2.1472
# span 2 = -0.0185, 2.1475
# span 3 = 20.000, 2003.000
# span 4 = 28.408623, 30.786419
# span 5 = 28.391335, 30.778093
# span 6 = 88.66, 90.21
# span 7 = 0.42404, 1.48661
# span 8 = 2.240e+00, 1.526e+01
# span 9 = 4.04335, 22.30740
# span 10 = -1.016e-02, 8.355e-02
# span 11 = 19.805, 1974.128
# span 12 = -0.0216, 2.1340
# span 13 = 33.6865, 34.7396
# span 14 = 0.000, 7.193
# span 15 = 0.0000, 0.7193
# span 16 = 26.9726, 27.8320
# span 17 = 26.9725, 27.8249
# span 18 = 0.000e+00, 0.000e+00
# interval = decibars: 1
# start_time = Apr 08 1997 21:36:18
# bad_flag = -9.990e-29
# sensor 0 = Frequency 0 temperature, primary, 2299, 04-Jan-97
# sensor 1 = Frequency 1 conductivity, primary, 1852, 09-JAN-97, cpcor = -9.5700e-08
# sensor 2 = Frequency 2 pressure, 43528, 27-Jan-95
# sensor 3 = Frequency 3 temperature, secondary, 2308, 04-Jan-97
# sensor 4 = Frequency 4 conductivity, secondary, 1850, 09-Jan-97, cpcor = -9.5700e-08
# sensor 5 = Extrnl Volt 0 oxygen, current, 6-01-06(sbe, 29- OCT 96
# sensor 6 = Extrnl Volt 1 oxygen, temperature, 6-01-06(sbe, 29- OCT 96
# sensor 7 = Extrnl Volt 2 transmissometer, 157D, 23 Jan 1997
# sensor 8 = Extrnl Volt 3 fluorometer, chelsea, 88/699/015, 13-DEC-96
# sensor 9 = Extrnl Volt 4 sea tech ls6000, 326, 05-17-96
# sensor 10 = Extrnl Volt 5 irradiance (PAR), 4469, 09-11-96
# datcnv_date = Apr 08 1997 23:25:35, 4.218
# datcnv_in = 97330001.DAT CTD_24.CON
# datcnv_skipover = 0
# wildedit_date = Apr 08 1997 23:28:02, 4.218
# wildedit_in = 97330001.CNV
# wildedit_pass1_nstd = 2.0
# wildedit_pass2_nstd = 20.0
# wildedit_npoint = 100
# wildedit_vars = scan t068 t168 pr c0mS/cm c1mS/cm xmiss stLs6000 par oxML/L flC
# wildedit_excl_bad_scans = yes
# celltm_date = Apr 08 1997 23:29:27, 4.218
# celltm_in = 97330001.CNV
# celltm_alpha = 0.0300, 0.0000
# celltm_tau = 7.0000, 0.0000
# filter_date = Apr 08 1997 23:30:47, 4.218
# filter_in = 97330001.CNV
# filter_low_pass_tc_A = 0.030
# filter_low_pass_tc_B = 0.150
# filter_low_pass_A_vars = c0mS/cm c1mS/cm
# filter_low_pass_B_vars = pr
# loopedit_date = Apr 08 1997 23:33:48, 4.218
# loopedit_in = 97330001.CNV
# loopedit_minVelocity = 0.250
# loopedit_excl_bad_scans = yes
# binavg_date = Apr 08 1997 23:35:50, 4.218
# binavg_in = 97330001.CNV
# binavg_bintype = Pressure Bins
# binavg_binsize = 1.00
# binavg_excl_bad_scans = yes
# binavg_downcast_only = yes
# binavg_skipover = 0
# binavg_surface_bin = yes, min = 0.300, max = 0.500, value = 0.000
# derive_date = Apr 08 1997 23:36:52, 4.218
# derive_in = 97330001.CNV CTD_24.CON
# file_type = ascii
*END*
----------------------------------------------------------------
Calibration:
Calibration for Conductivity and Salinity:
The CTD Conductivity sensor was calibrated by correlating the CTD
downcast conductivities with the conductivities of the water samples
taken with the SEA-BIRD carousel on the upcast. The mean and
standard deviations of these differences using all of the available
bottle data are given below.
There appeared to be some flushing problems with the
nisken bottles in the high gradient region near the surface. Therefore,
the data collected below the high gradient region were used in the
calibration of the CTD sensor. Subsets of these data were also used
to see if there was any significant drift of the CTD sensors during
the cruise. In this case there was a signigicant drift in the sensors
during the cruise. As a result, the stations were divided into 3
sub-sets and different calibrations were applied to each subset.
In addition, only the salinities collected below 175 meters depth were
used in this correlation for the first and third time periods
(it was not necessary to do this for the second time period as these
data were not collected in a region that had has high surface gradients).
If the full pressure range was used the mean remains the same,
the the STDEV increases as would be expected for the high-gradient,
variable surface layers.
SUBSET 1:
/aesops/NBP9703/FINAL_DATA/97330001.cnf
/aesops/NBP9703/FINAL_DATA/97330102.cnf
/aesops/NBP9703/FINAL_DATA/97330103.cnf
/aesops/NBP9703/FINAL_DATA/97330104.cnf
/aesops/NBP9703/FINAL_DATA/97330302.cnf
/aesops/NBP9703/FINAL_DATA/97330304.cnf
/aesops/NBP9703/FINAL_DATA/97330305.cnf
/aesops/NBP9703/FINAL_DATA/97330401.cnf
/aesops/NBP9703/FINAL_DATA/97330403.cnf
/aesops/NBP9703/FINAL_DATA/97330405.cnf
/aesops/NBP9703/FINAL_DATA/97330406.cnf
/aesops/NBP9703/FINAL_DATA/97330407.cnf
/aesops/NBP9703/FINAL_DATA/97330408.cnf
/aesops/NBP9703/FINAL_DATA/97330409.cnf
/aesops/NBP9703/FINAL_DATA/97330411.cnf
/aesops/NBP9703/FINAL_DATA/97330501.cnf
/aesops/NBP9703/FINAL_DATA/97330502.cnf
/aesops/NBP9703/FINAL_DATA/97330504.cnf
/aesops/NBP9703/FINAL_DATA/97330506.cnf
/aesops/NBP9703/FINAL_DATA/97330508.cnf
/aesops/NBP9703/FINAL_DATA/97330509.cnf
MINIMUM PRESSURE USED = 175 db
Conductivity STDEV= 0.003 MEAN= -0.005
Salinity STDEV= 0.003 MEAN= -0.007
Therefore, a correction of .005 was applied to the CTD conductivities.
The reported Conductivities and Salinities are good to +/- .003.
SUBSET 2:
/aesops/NBP9703/FINAL_DATA/97330602.cnf
/aesops/NBP9703/FINAL_DATA/97330603.cnf
/aesops/NBP9703/FINAL_DATA/97330605.cnf
/aesops/NBP9703/FINAL_DATA/97330606.cnf
/aesops/NBP9703/FINAL_DATA/97330701.cnf
/aesops/NBP9703/FINAL_DATA/97330704.cnf
/aesops/NBP9703/FINAL_DATA/97330705.cnf
/aesops/NBP9703/FINAL_DATA/97330707.cnf
/aesops/NBP9703/FINAL_DATA/97330801.cnf
/aesops/NBP9703/FINAL_DATA/97330901.cnf
/aesops/NBP9703/FINAL_DATA/97331002.cnf
/aesops/NBP9703/FINAL_DATA/97331003.cnf
/aesops/NBP9703/FINAL_DATA/97331004.cnf
/aesops/NBP9703/FINAL_DATA/97331006.cnf
/aesops/NBP9703/FINAL_DATA/97331101.cnf
/aesops/NBP9703/FINAL_DATA/97331102.cnf
/aesops/NBP9703/FINAL_DATA/97331201.cnf
/aesops/NBP9703/FINAL_DATA/97331202.cnf
MINIMUM PRESSURE USED = 0 db
Conductivity STDEV= 0.002 MEAN= -0.010
Salinity STDEV= 0.002 MEAN= -0.014
Therefore, a correction of .010 was applied to the CTD conductivities.
The reported Conductivities and Salinities are good to +/- .002.
SUBSET 3:
/aesops/NBP9703/FINAL_DATA/97331301.cnf
/aesops/NBP9703/FINAL_DATA/97331302.cnf
/aesops/NBP9703/FINAL_DATA/97331401.cnf
/aesops/NBP9703/FINAL_DATA/97331402.cnf
/aesops/NBP9703/FINAL_DATA/97331403.cnf
/aesops/NBP9703/FINAL_DATA/97331404.cnf
/aesops/NBP9703/FINAL_DATA/97331405.cnf
/aesops/NBP9703/FINAL_DATA/97331601.cnf
/aesops/NBP9703/FINAL_DATA/97331602.cnf
/aesops/NBP9703/FINAL_DATA/97331603.cnf
/aesops/NBP9703/FINAL_DATA/97331604.cnf
/aesops/NBP9703/FINAL_DATA/97331605.cnf
/aesops/NBP9703/FINAL_DATA/97331606.cnf
/aesops/NBP9703/FINAL_DATA/97331607.cnf
/aesops/NBP9703/FINAL_DATA/97331608.cnf
/aesops/NBP9703/FINAL_DATA/97331609.cnf
/aesops/NBP9703/FINAL_DATA/97331610.cnf
/aesops/NBP9703/FINAL_DATA/97331701.cnf
/aesops/NBP9703/FINAL_DATA/97331801.cnf
/aesops/NBP9703/FINAL_DATA/97331901.cnf
MINIMUM PRESSURE USED = 175 db
Conductivity STDEV= 0.001 MEAN= -0.014
Salinity STDEV= 0.002 MEAN= -0.016
Therefore, a correction of .016 was applied to the CTD conductivities.
The reported Conductivities and Salinities are good to +/- .002.
-----------------------------------------------------------------------------
The Digital dissolved oxygen sensor did not provide reliable data
during this cruise. The CTD transmissometer, fluorometer, light
scattering and PAR measurements are currently being calibrated by
other investigators.
It should be noted that the original Chelsea fluorometer failed on station
97331001.CNV and was replaced with a Sea Tech fluorometer.
-----------------------------------------------------------------------------
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
EMAIL: John_Morrison@NCSU.EDU
PHONE: 919-515-7449
FAX: 919-515-7802