North Pole Environmental Observatory
NSF Grant OPP-9910305
2001 Aerial CTD Survey

  CTD Cast       Station Location             CTD Position                  Cast Date & Time    

  Cast 2         NPEO 2001 Deployment Camp    89deg 34.2' N _  73deg 03.5' E    4/ 9/2001 _ 1738 UTC 
  Cast 3         NPEO 2000 Cast 4             87deg 28.4' N _  90deg 50.2' W    4/ 9/2001 _ 2118 UTC 
  Cast 4         NPEO 2000 Cast 6             84deg 55.4' N _  67deg 23.4' W    4/10/2001 _ 1352 UTC
  Cast 5         NPEO 2000 Cast 1             89deg 38.3' N _ 166deg 44.5' W    4/11/2001 _ 1849 UTC
  Cast 6         Pole-toward-Alaska Line      87deg 14.7' N _ 179deg 48.5' E    4/12/2001 _ 1853 UTC
  Cast 7         Pole-toward-Alaska Line      88deg 59.2' N _ 179deg 41.4' W    4/12/2001 _ 2242 UTC
  Cast 8         Pole-toward-Alaska Line      85deg 01.3' N _ 166deg 28.9' W    4/13/2001 _ 1656 UTC
  Cast 9         Pole-toward-Alaska Line      86deg 08.2' N _ 171deg 02.0' W    4/13/2001 _ 2003 UTC
  Cast 10        NPEO 2001 Deployment Camp    89deg 28.3' N _  54deg 43.2' E    4/14/2001 _ 1302 UTC



Each cast is an ASCII file of five columns with a short header-
  _ Depth (m)
  _ Pressure (dbar)
  _ Temperature (degC)
  _ Conductivity (S/m)
  _ Salinity (psu)
  
These measurements were made with a Seabird SBE-19 Seacat following a landing at these positions
on the Arctic sea ice by Twin Otter skiplane, part of the observational program of the North Pole 
Environmental Observatory.  Cast 1 was an instrument test of no oceanographic significance.

Processing followed the SEASOFT recipe to minimize salinity spiking and correct for a thermal lag 
of the conductivity cell, with certain constants determined by empirical trial.  Conductivity was 
low pass filtered with a time constant of 0.3 seconds, and temperature was advanced relative to 
pressure by 0.6 seconds.  SEASOFT's thermal lag correction was applied with alpha=0.03 and tau=9.0.

Following the processing recipe, these profiles are generally the corrected downcasts.  Because of 
the difficulty of conducting a cast in severely cold air temperature, however, the top of some 
downcasts was compromised by the cast starting down at too cold an instrument temperature despite 
a substantial soak time.  In certain of these cases, the top of the upcast was grafted on the top 
of the downcast.

Profile plots and other analysis using these data may be viewed at the NPEO website
   (http://psc.apl.washington.edu/northpole/CTDSurvey2001.html).

    For further information, please contact
Dr. James Morison     morison@apl.washington.edu     (206) 543-1394
Dr. Michael Steele    mas@apl.washington.edu         (206) 543-6586
Roger Andersen        roger@apl.washington.edu       (206) 543-1258
    at
Polar Science Center, Applied Physics Lab, University of Washington
1013 NE 40th, Seattle, WA  98105-6698   USA      FAX (206) 616-3142
