======================== Originally posted 2010-8-26 ============================= North Pole Environmental Observatory 2010 Expendble Current Profiles NSF Grants ARC-0909408 Sensitivity of Arctic Ocean Change to Background Mixing and ARC-0856330, OPP-9910305, OPP-0352754 North Pole Environmental Observatory Dropped at NPEO 2010 CTD Station 1 Barneo XCP Drop 1 2010-04-19/1608 UTC 89deg 06.4min North 078deg 12.4min East XCP Drop 4 2010-04-19/2250 UTC 89deg 06.7min North 076deg 40.6min East XCP Drop 5 2010-04-20/ 624 UTC 89deg 06.1min North 075deg 11.2min East Dropped at NPEO 2010 CTD Station 2 NP85E90 XCP Drop 6 2010-04-22/1430 UTC 84deg 59.5min North 084deg 59.1min East Dropped at NPEO 2010 CTD Station 3 NP86E90 XCP Drop 7 2010-04-22/1824 UTC 85deg 59.1min North 089deg 34.4min East Dropped at NPEO 2010 CTD Station 4 NP90 XCP Drop 8 2010-04-23/1115 UTC 89deg 59.5min North 007deg 04.0min West XCP Drop 9 2010-04-23/1204 UTC 89deg 59.5min North 007deg 04.0min West Dropped at NPEO 2010 CTD Station 5 NP88E90 XCP Drop 10 2010-04-23/1611 UTC 87deg 57.4min North 089deg 13.4min East XCP Drop 11 2010-04-23/1611 UTC 87deg 57.4min North 089deg 13.4min East Dropped at NPEO 2010 CTD Station 6 NP87_180 XCP Drop 12 2010-04-24/1812 UTC 86deg 58.3min North 179deg 50.3min East XCP Drop 13 2010-04-24/1830 UTC 86deg 58.3min North 179deg 50.3min East Dropped at NPEO 2010 CTD Station 7 NP86W173 XCP Drop 14 2010-04-24/2242 UTC 86deg 00.2min North 173deg 17.2min West XCP Drop 15 2010-04-24/2257 UTC 86deg 00.2min North 173deg 17.2min West Dropped at NPEO 2010 CTD Station 8 NP89_180 XCP Drop 16 2010-04-25/1422 UTC 89deg 01.1min North 178deg 39.9min West XCP Drop 17 2010-04-25/1438 UTC 89deg 01.1min North 178deg 39.9min West XCP Drop 18 2010-04-25/1453 UTC 89deg 01.1min North 178deg 39.9min West XCP Drop 19 2010-04-25/1520 UTC 89deg 01.1min North 178deg 39.9min West These measurements were made with a Sippican Expendable Current Profiler following a Twin Otter landing at these positions on the Arctic sea ice, as part of the observational program of the North Pole Environmental Observatory. A brief description of XCPs may be found at http://www.sippican.com/contentmgr/showdetails.php/id/312 . XCP Drops 2 and 3 failed to record. CTD profiles recorded during the same stations are included in the Dataset - North Pole Environmental Observatory Aerial CTD Survey at CADIS ( http://aoncadis.ucar.edu/home.htm ), and are a source of buoyancy data for further XCP analysis. The XCP measures velocity by sensing the voltage generated by the movement of conductive seawater through the earth's magnetic field. The voltage difference is measured between two electrodes on the surface of the XCP, which rotates about once every meter of fall. We use a MATLAB program written by John Dunlap of the UW Applied Physics Lab to process the raw data. This program is available at http://ohm.apl.washington.edu/~dunlap/xcpdsp/ In processing, the components of a harmonic fit to the oscillating potential that are in phase and in quadrature with the oscillating output of a flux gate compass are taken as the magnetic north and magnetic east components of velocity. In order to maximize the potential vertical resolution of the resulting profiles, we chose to do the fits over 2-m, half overlapping "chunks". This gives a vertical wavenumber cutoff of 0.5 cycle m-1 that for the Arctic data is well into the noise floor of the instrument. Users may then filter these basic data in ways appropriate to their applications. Further analysis using these data may be viewed at (http://psc.apl.washington.edu/northpole/Mixing.html). For further information, please contact Dr. James Morison morison@apl.washington.edu (206) 543-1394 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