HR: 0800h
AN: OS21C-1260    [Abstracts]
TI: The Nuka Arctica Line
AU: Svendsen, H
EM: harald.svendsen@gfi.uib.no
AF: Bjerknes Centre for Climate Research, Allegata 70, Bergen, N-5007 Norway
AU: Knudsen, O
EM: oyvind.knudsen@gfi.uib.no
AF: Bjerknes Centre for Climate Research, Allegata 70, Bergen, N-5007 Norway
AU: Rossby, T
EM: trossby@gso.uri.edu
AF: Graduate School of Oceanography, University of Rhode Island, Kingston, RI 02881 United States
AU: * Osterhus, S
EM: ngfso@uib.no
AF: Bjerknes Centre for Climate Research, Allegata 70, Bergen, N-5007 Norway
AB: In order to develop an accurate understanding of the mean circulation and its variability in the northeast Atlantic over a wide range of timescales, the Nuka Arctica project was established to measure currents directly using a hull-mounted ADCP onboard the container vessel `Nuka Arctica' that operates between Denmark and Greenland on a three-week schedule. Since late 1999, the `Nuka Arctica' has collected velocity data from nearly 50 transects. The circulation around the Reykjanes Ridge stands out very clearly with a southward flow on its eastern flank and a well-defined northward flow along its western slope. We also find a well-defined flow northward through the Iceland Basin. The East Greenland Current as it passes around Cape Farewell stands out clearly. These mean flow patterns appear to be robust thanks to the many sections available. In contrast, except for the East Greenland Current, these currents cannot be discerned in any single section. There are two reasons for this: First, as is well-known, the eddy velocity field is much larger than the mean flow, and second, the mean flows along the ridge are rather narrow and topographically defined. Thus they cannot be recovered from individual sections by simply averaging over a longer section. The fact that the mean field emerges so clearly through ensemble-averaging underscores how effective repeat sampling from volunteer observing vessels can be. The long-range objective of this program is to obtain a very accurate estimate of the mean flow relative to which low frequencies variations and their causes can be explored.
UR: http://www.gfi.uib.no/forskning/Nuka_Arctica
DE: 4294 Instruments and techniques
DE: 4512 Currents
DE: 4532 General circulation
DE: 4540 Ice mechanics and air/sea/ice exchange processes
DE: 0930 Oceanic structures
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting