Title: Discoverer CTD Data

Contact:

   James E. Johnson
   OCRD
   NOAA/Pacific Marine Environmental Laboratory
   7600 Sand Point Way NE
   Seattle, WA, USA, 98115
   Telephone: (206) 526-6355
   Facsimile: (206) 526-6744
   E-Mail Address: johnson@pmel.noaa.gov

Or

   Timothy S Bates
   OCRD
   NOAA/PMEL
   7600 Sandpoint Way NE
   Seattle, WA  98115
   USA
   Phone: 206-526-6248
   Fax: 206-526-6744
   E-Mail Address: bates@pmel.noaa.gov


Data Set Description:

NOAA ship Discoverer
CTD cast Data
Reduced and Compiled by NOAA-PMEL
Version 1, 26 March 1996
Jim Johnson and Tim Bates

1995 CTD system:

A seabird SBE-9 Plus CTD (serial number 337, conductivity sensor S.N.
1230, temperature sensor N.N. 1558) was used at all stations.  The CTD was
calibrated by the Northwest Regional Calibration Center on 10/11/95.  The
CTD, rosette, stand, and bottles belonged to Discoverer.  The sample bottles
were 10L Niskin bottles with silicone O-rings and tubing.  Near the end of leg
2 the yoke on the stand parted and the entire system was lost.

A total of 28 CTD stations were occupied on Leg I and 8 CTD stations on leg
II.  Each CTD cast was labeled with a 5 digit number.  The first digit refers
to the leg of the cruise (1 or 2), the next 3 digits refer to the station
number, and the last digit is the cast number at that station.  For example
10121 would be leg 1, station number 12, cast 1.  For each CTD cast there
are 2 data files. One data set gives the location, time and the readings from
the cast (pressure, temperature, conductivity, depth, salinity, and density)
averaged into 2 meter bins. The second data set gives the potential
temperature, salinity, pressure, temperature  and conductivity when each
Niskin bottle was closed.

Chlorophyll samples were collected at each sampling depth at each station.
Samples were collected (530 ml), immediately filtered, put into 10 ml of 90%
acetone, and frozen by ship's survey department.  The samples were analyzed
within 3-4 days aboard ship with using a Turner fluorometer.  The
fluorometer was calibrated after the cruise using chlorophyll 'a' from the
Sigma Chemical Corp.  The data are reported in units of micrograms per liter.


Format: ASCII data.

The chlorophyll data file (chlorsta.dat) contains comma separated
ASCII data with columns:

Date
Time
Cast
Depth
Chlorophyll 'a' (ug/L)


The closed data files (di*.dat) contain a number of header lines
that begin with '*' or '#', followed by columnar ASCII data with fields:

Bottle Position
Date Time
Potemp068
Sal00
Pr
T068
C0S/m

Each bottle position contains 4 lines of data giving avg,sdev,min,max values.


The cast data files (as*.dat) contain a number of header lines
that begin with '*' or '#', followed by columnar ASCII data with
a subset of the following fields (see the file's header lines for
the parameters in that file):

All files begin with the columns:
pr: pressure [db]
t068: temperature, IPTS-68 [deg C]
c0S/m: conductivity [S/m]

Some subset and ordering of the following columns:
depS: depth, salt water [m]
sal00: salinity, PSS-78 [PSU]
svD: sound velocity, delgrosso [m/s]
flag:  0.000e+00
sigma-00: density, sigma-theta [kg/m^3]

All files end with the column:
nbin: number of scans per bin


File Name Conventions:

chlorsta.dat - chlorophyll data

Cast and closed data files are named:
XXLSSSC.dat where XX is the data type ("as" for cast data, "di" for closed),
L is the leg number, SSS is the station number, and C is the cast number.
For example leg 1, station number 12, cast 1, is 10121.
The cast data is in as10121.dat and the closed data in di10121.dat.


References: None.