Mooring Design Deployment and Recovery

Between 2001 and 2010, NPEO
maintained an oceanographic mooring anchored to the the abyssal plain near the North Pole. Supported by floats at several levels, the mooring line stretched upward nearly to the surface over 4000 meters above the sea floor, allowing instruments to be mounted at fixed levels recording at fixed intervals within the water column. Measurements included ice thickness and drift, water temperature and salinity, and current speed and direction, from near the surface to great depths.

Mooring Deployed Recovered Latitude Longitude Depth
10 April 2001
22 April 2002
89° 33.412' N
66° 38.820' E
23 April 2002
24 April 2003
89° 27.457' N
53° 31.258' E
25 April 2003
19 April 2004
89° 23.336' N
46° 07.156' E
21 April 2004
20 April 2005
89° 27.288' N
54° 19.744' E
22 April 2005
22 April 2006
89° 15.172' N
64° 41.509' E
24 April 2006
11 April 2008
89° 20.810'N
77° 07.208'E
17 April 2008
16 April 2010
89° 31.527'N
84° 22.488'E

Each instrument recorded internally, which meant that the mooring had to be retrieved in order to download the data from each instrument. After the first deployment in 2001, one-year data storage capacities dictated a mooring recovery and deployment of a new mooring each year. Improvements in data storage proved fortunate in 2007 when extreme weather prevented a visit to the site and the 2006 mooring remained in place for a second year. Most of the those instruments returned a complete, or nearly complete, two-year record, and the 2008 mooring was then recovered as planned in April 2010.

Since 2010, NPEO's only bottom-anchored measurements have been made by the Arctic Bottom Pressure Recorder (ABPR), on the sea floor at 90° North.

A mooring recovery requires returning to the precise position, and the uncertainty of finding a landing strip for a skiplane on the sea ice dictated a helicopter. The intent was to maintain each year's mooring at the same position. However, slight differences are operationally unavoidable, because of the ice drift during the one-to-three day period between the release of the old mooring and actual deployment of the new one. Closeness to the Pole accounts for the wild-appearing changes in longitude.

Data from NPEO's bottom-anchored moorings
are permanently archived at the Cooperative Arctic Data and Information Service (ACADIS) and Arctic System Science (ARCSS) Data Archive.  These data may also be obtained via FTP at this website.