North Pole Environmental Observatory
NSF Grant OPP-9910305
2000 Aerial CTD Survey

  CTD Station    Station Location             Position                      Date & Time    

  Station 1      NPEO 2000 Deployment Camp    89deg 40.8' N _ 138deg 46.2' W    4/22/2000 _ 1401 UTC 
  Station 2      Alert to Pole Transect       89deg 02.6' N _  92deg 03.0' W    4/24/2000 _ 1843 UTC 
  Station 3                                   89deg 08.4' N _  64deg 27.4' E    4/23/2000 _ 2030 UTC 
  Station 4      Alert to Pole Transect       87deg 29.1' N _  90deg 51.0' W    4/22/2000 _ 2047 UTC
  Station 5      Alert to Pole Transect       85deg 57.3' N _  68deg 38.0' W    4/16/2000 _ 1908 UTC
  Station 6      Alert to Pole Transect       84deg 56.0' N _  67deg 28.1' W    4/25/2000 _ 1730 UTC
  Station 7      Alert to Pole Transect       86deg 51.0' N _  96deg 13.6' W    4/28/2000 _ 1645 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.  

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, pressure filtered with a time constant of 
2.0 seconds, and temperature was advanced relative to pressure by 0.7 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
