Weddell Sea

Electrical conductivity of the water column; Salinity of the water column; Temperature of the water column

Sea level recorders; bathythermographs; cameras; CTD

The project was designed to match surface observations of sea ice properties with aerial photographic swathes and satellite SAR imagery, in order to elucidate the nature of the Antarctic ice edge in late summer and its signature on SAR. The ship entered the northwest Weddell Sea through Antarctic Sound and carried out a series of experiments during a seven-day period. On each day the ship would run into the ice along a line that was being covered by an ERS-1 SAR orbit, using her Lynx helicopters to land the SPRI team on a succession of ice floes. On each floe the party took an ice core, measured snow and ice physical properties, recorded strain and accelerations due to ocean waves, and took CTD (conductivity-temperature-depth) profiles through the uppermost 80 m of the water column to measure melt water effects. Meanwhile the ship was carrying out CTD profiles at 5-10 nml intervals. As near as possible to the exact time of the satellite overflight a helicopter would carry out a 100 nml aerial photography flight along the line of the orbit. By matching these datasets from three levels (satellite, airborne, surface) we have been able to gain new insight into the radar reponse of Antarctic sea ice, also making the discovery that late summer sea ice in the Weddell Sea is covered with melt pools, a phenomenon previously thought to be confiend to the Arctic. Strain and acceleration measurements were also carried out on two tabular icebergs.

Scott Polar Research Institute
University of Cambridge Lensfield Road
Cambridge

CB2 1ER
United Kingdom