============================== Originally posted 2014-10-21 =================================== North Pole Environmental Observatory 2012 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 NPEO 2012 XCP Profiles NPEO 2012 Date / Time Latitude Longitude XCP s/n MagDec Filename (E+/W-) XCP Drop 1 2012-4-15/1155 UTC 89 20.0 North 002 35.0 East 11111006 -6.93 NP12_xcp01_Sergei.txt XCP Drop 2 2012-4-16/1514 UTC 84 57.0 North 089 54.1 East 11111011 60.13 NP12_xcp02_85_90E.txt XCP Drop 3 2012-4-16/1532 UTC 84 57.0 North 089 54.1 East 11111018 60.13 NP12_xcp03_85_90E.txt XCP Drop 4 2012-4-16/1850 UTC 85 58.5 North 090 09.8 East 11111012 64.19 NP12_xcp04_86_90E.txt XCP Drop 5 2012-4-17/1333 UTC 84 57.3 North 169 49.1 West 11111009 25.52 NP12_xcp05_85_170W.txt XCP Drop 6 2012-4-17/1726 UTC 86 00.3 North 175 22.7 West 11111003 50.16 NP12_xcp06_86_175W.txt XCP Drop 7 2012-4-18/1106 UTC 89 14.2 North 002 04.4 West 11101062 -11.37 NP12_xcp07_Sergei.txt XCP Drop 8 2012-4-18/1117 UTC 89 14.2 North 002 04.4 West 11101008 -10.63 NP12_xcp08_Barneo.txt XCP Drop 9 2012-4-18/1136 UTC 89 14.0 North 002 00.4 West 11111008 -10.70 NP12_xcp09_WhiteT.txt XCP Drop 10 2012-4-18/1505 UTC 89 13.9 North 002 14.7 West 11111013 -10.48 NP12_xcp10_Sergei.txt XCP Drop 11 2012-4-18/1518 UTC 89 14.2 North 002 32.6 West 11111010 -10.18 NP12_xcp11_Runway.txt XCP Drop 12 2012-4-18/1525 UTC 89 13.8 North 002 09.0 West 11111016 -11.43 NP12_xcp12_WhiteT.txt XCP Drop 13 2012-4-18/1905 UTC 89 13.5 North 002 23.1 West 11101068 -10.35 NP12_xcp13_Sergei.txt XCP Drop 14 2012-4-18/1915 UTC 89 13.7 North 002 46.5 West 11101049 -12.03 NP12_xcp14_Runway.txt XCP Drop 15 2012-4-18/1922 UTC 89 13.4 North 002 18.0 West 11101066 -10.44 NP12_xcp15_WhiteT.txt XCP Drop 16 2012-4-18/2303 UTC 89 13.1 North 002 28.4 West 11101065 -10.28 NP12_xcp16_Sergei.txt XCP Drop 17 2012-4-18/2312 UTC 89 13.4 North 002 46.0 West 11101035 -12.01 NP12_xcp17_Runway.txt XCP Drop 18 2012-4-18/2320 UTC 89 12.9 North 002 23.3 West 11031033 -10.37 NP12_xcp18_WhiteT.txt XCP Drop 19 2012-4-19/0305 UTC 89 12.6 North 002 40.9 West 11101033 -10.10 NP12_xcp19_Sergei.txt XCP Drop 20 2012-4-19/0317 UTC 89 12.8 North 003 05.2 West 11101060 -12.30 NP12_xcp20_Runway.txt XCP Drop 21 2012-4-19/0324 UTC 89 12.4 North 002 36.1 West 11111007 -11.82 NP12_xcp21_WhiteT.txt XCP Drop 22 2012-4-19/0705 UTC 89 12.1 North 002 56.1 West 11101005 -11.87 NP12_xcp22_Sergei.txt XCP Drop 23 2012-4-19/0714 UTC 89 12.4 North 003 13.3 West 11101036 -11.59 NP12_xcp23_Runway.txt XCP Drop 24 2012-4-19/0721 UTC 89 12.0 North 002 50.7 West 11111017 -12.04 NP12_xcp24_WhiteT.txt XCP Drop 25 2012-4-19/1414 UTC 87 24.0 North 179 50.0 East 11111014 143.66 NP12_xcp25_87_180.txt XCP Drop 26 2012-4-19/1837 UTC 88 56.3 North 179 24.7 East 11101071 164.27 NP12_xcp26_89_180.txt XCP Drop 27 2012-4-20/1216 UTC 87 14.7 North 091 35.9 East 11101059 70.10 NP12_xcp27_87_90E.txt XCP Drop 28 2012-4-20/1531 UTC 88 00.1 North 089 58.8 East 11101034 71.69 NP12_xcp28_88_90E.txt XCP Drop 29 2012-4-22/1108 UTC 89 59.7 North 113 09.0 West 11101059 -123.87 NP12_xcp29_90N.txt XCP Drop 30 2012-4-22/1503 UTC 89 01.8 North 090 22.6 East 11101064 75.80 NP12_xcp30_89_90E.txt 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 files with a suffix like _Sergei, _Barneo, _WhiteT, and _Runway together form a time series at the 2012 Ice Station Barneo. Those with a suffix like _88_90E were recorded at an NPEO Aerial CTD station of that name following a Twin Otter skiplane landing at that positions on the Arctic sea ice. CTD profiles 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. Other projects that collected Arctic XCP data and analysis related to 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