NPEO/IPY 2008 Beaufort Sea CTD/AXCTD Survey

 
Beaufort Sea region-

Compared with spring 2007, weather and particularly ice conditions were much more favorable for the Twin Otter CTD survey during 2008. Landings by skiplanes on unprepared ice floes were greatly aided by the nearly universal presence of smooth, first year ice which made locating landing sites relatively easy.

Thanks to NSF's International Polar Year (IPY), 2007-2008 Initiative, the NPEO hydrographic survey in 2008 began March 20 with the IPY extended sampling program of the Beaufort Sea by Twin Otter. Fifteen CTD-Chemistry surface stations were obtained across the southern Beaufort from 136 °West out to 163° West, in unusually cold air temperatures.

Trying to extend the IPY Beaufort coverage farther north than was reachable from Deadhorse, Alaska in the skiplane, a second Twin Otter on standard (thin) wheels and with dual, long-range ferry tanks flew two days in mid-April north from Deadhorse, seeking to drop Airborne eXpendable Conductivity, Temperature, and Depth probes ( AXCTD.pdf ) into open leads, and record the profiles without landing. The relatively smooth, uniform ice cover with persistently cold air temperatures presented few cracks new enough to be feasible drop targets, especially in the northwest Beaufort, but eight successful CTD profiles were obtained. Two had to be repeated to penetrate a thin slush layer.

The 23 IPY Beaufort Sea CTD profiles are being compared with stations obtained in the same area by the WHOI's Beaufort Gyre Expedition Project using the Canadian Coast Guard Icebreaker Louis S. St-Laurent on its Joint Western Arctic Climate Study (JWACS) cruise during August 2007. This comparison spans the extraordinary melting of September 2007 and subsequent freezeup through the following winter.

2007CTD_Clickmap

2008 CTD
Station/Location
Position
Cast Date and Time
Surface Cast 1 Sta73_140W
73° 00.000' N 140° 00.000' W
2008-03-21/2156 UTC
Surface Cast 2 Sta72_140W
72° 03.030' N 140° 06.710' W
2008-03-22/2145 UTC
Surface Cast 3 Sta7240_145W
72° 41.210' N 144° 50.420' W
2008-03-23/0136 UTC
Surface Cast 4 Sta7340_135W
73° 35.190' N 136° 32.470' W
2008-03-23/2054 UTC
Surface Cast 5 Sta74_140W
74° 02.360' N 140° 18.670' W
2008-03-24/0045 UTC
Surface Cast 6 Sta7440_146W
74° 38.130' N 146° 40.300' W
2008-03-24/2050 UTC
Surface Cast 7 Sta7420_143W
74° 18.060' N 143° 17.040' W
2008-03-24/2350 UTC
Surface Cast 8 Sta75_150W
74° 58.690' N 150° 08.670' W
2008-03-26/2033 UTC
Surface Cast 9 Sta74_150W
74° 03.360' N 149° 48.620' W
2008-03-27/0019 UTC
Surface Cast 10 Sta73_150W
72° 58.310' N 149° 51.870' W
2008-03-27/1948 UTC
Surface Cast 11 Sta72_150W
72° 03.740' N 150° 05.270' W
2008-03-27/2259 UTC
Surface Cast 12 Sta7540_158W
75° 41.930' N 157° 42.870' W
2008-03-29/2046 UTC
Surface Cast 13 Sta7520_154W
75° 21.600' N 154° 18.320' W
2008-03-29/2349 UTC
Surface Cast 14 Sta7620_164W
76° 19.290' N 163° 41.840' W
2008-03-30/2020 UTC
Surface Cast 15 Sta76_161W
75° 56.450' N 160° 37.110' W
2008-03-30/2317 UTC
Air Drop 1 AXCTD
76° 00.41' N 147° 24.91'W
2008-04-17/0515 UTC
Air Drop 2 AXCTD
75° 04.33' N 149° 32.31'W
2008-04-17/0618 UTC
Air Drop 3 AXCTD
75° 03.99' N 140° 08.90'W
2008-04-18/0020 UTC
Air Drop 4 AXCTD
76° 23.48' N 137° 24.50'W
2008-04-18/0224 UTC
Air Drop 5 AXCTD
76° 53.65' N 139° 08.00'W
2008-04-18/0207 UTC
Air Drop 6 AXCTD
77° 06.20' N 141° 49.80'W
2008-04-18/0245 UTC
Air Drop 7 AXCTD
77° 27.30' N 144° 39.50'W
2008-04-18/0347 UTC
Air Drop 8 AXCTD
75° 46.65' N 145° 31.95'W
2008-04-18/0445 UTC

 

Data from the NPEO aerial hydrographic and chemistry surveys are permanently archived at the Arctic System Science (ARCSS) Data Coordination Center. Currently available are CTD Profiles and Seawater Chemistry.  These data plus certain preliminary data sets may be obtained via FTP at this website.