HR: 0800h
AN: OS21C-1261    [Abstracts]
TI: Deepwater formation in the Southern Weddell Sea, processes, pathways and fluxes
AU: * Osterhus, S
EM: ngfso@uib.no
AF: Bjerknes Centre for Climate Research, Allegata 70, Bergen, N5007 Norway
AU: * Osterhus, S
EM: ngfso@uib.no
AF: British Antarctic Survey, High Cross, Madingley Road Cambridge U.K, Cambridge, CB3 0ET United Kingdom
AU: Nicholls, K
EM: kwni@bas.ac.uk
AF: British Antarctic Survey, High Cross, Madingley Road Cambridge U.K, Cambridge, CB3 0ET United Kingdom
AB: Ice Shelf Water (ISW) is the final product of the melting process underneath the floating ice shelves in the Antarctica. Recent drastic break-ups of the Larsen ice-shelf in the Weddell Sea has vitalised the question if this melting has increased. The most efficient production of ISW takes place under the immense Ronne - Filchner Ice shelves in the Southern Weddell Sea. The corresponding ISW flow out of the region was located in 1977, and a key location for long term monitoring was identified. Since then we have succeeded in occupying this station with instrumented moorings for about 5 years, which have given us valuable information of variability of the sub-ice shelf and continental shelf circulation. However, in addition to serve as an indicator for Antarctic ice-cap melting, it turns out that the ISW flow contribute to the formation of the Antarctic bottom water. Therefore it is driving the thermohaline circulation, which has a great impact on the global climate. There are several processes and regions in the Antarctic of importance for the bottom water formation. However, recent international efforts indicate that the ISW overflow and its cascading towards large oceans depths as a bottom trapped jet entrain waters from above, increasing the volume transport by a factor of about 2.5. The resulting volume transport estimates indicate that the processes involving ISW is dominating the deep and bottom water formation in the Antarctic.
UR: http://www.bjerknes.uib.no/research/
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