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 file (for example as10121.cnv) gives the location, time and the readings 
from the cast (pressure, temperature, conductivity, depth, salinity, and 
density) averaged into 2 meter bins.  The second file (for example 
di10121.btl) 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.  
The Chlorophyll data from the casts in given in file CHLORSTA.CSV.