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[1] Atmospheric cyclones in the Fram Strait affect the sea ice transport from the Arctic Ocean into the Atlantic Ocean. During the field experiment FRAMZY in April 1999 a Fram Strait cyclone and its impact on the ice drift was measured using a research aircraft and an array of 15 ice buoys. The synoptic-scale cyclone moved from the south into the area. It was discernible up to 500 hPa in the pressure field, but the horizontal temperature contrast of up to 16 K between the warm and cold sides was confined to the lowest 500 m. The average ice drift was 0.21 ms À1 toward 200°but increased to 0.6 ms À1 during the cyclone passage. The ice drift amounted to 1.6% of the geostrophic wind with a turning angle of 51°o n the average. Comparisons between the aircraft measurements and operational weather model analyses show an insufficient representation of the temperature inversion and indicate an underestimate of wind speed and, thus, momentum transfer to the sea ice.

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Abslract. Temperature observations of three buoys drifting in the Weddell Sea for one year and covering the ice-water-ice cycle from July 1986 to July 1987 are presented. Significant differences between winter and summer are shown to be a consequence of the air-sea heat exchange being drastically modified by the sea ice cover. Over ice, prevailing variance is in the synoptic scale (periods 3 to 5 days) with amplitudes of 25"C, whereas over water, the diurnal wave dominates with amplitudes of less than 1 "C.The southern ocean is unique on the globe in various respects. Except for minor spits of land -the antarctic peninsula and the southern tip of South America -no land mass confines the circumpolar current, quite in contrast to the northern hemisphere where continents force a much more meridional flow. Oceanic currents are governed by fluxes of momentum from air to sea which, integrated over the latitude circle, are larger than anywhere else. On the other hand, this exchange is effectively modulated by the annual advance and retreat of a solid lid of sea ice at the air-sea interface which also -and even more effectivelyinfluences exchange of sensible and latent heat. Sea ice in late winter (September) extends from the antarctic coast to as far north as 55" S and, thus, covers the belt of subantarctic low pressure systems prevailing in this area.Yet little observational evidence is available from this -as far as air-sea interaction is concerned -most interesting region. FCw land or island stations exist, and data may be biased since they do not represent the true marine environment. Drifting buoys have been deployed during FGGE in 1979, but unfortunately their temperature data appear to be of low quality due to poor sensor exposure (Ackley, 1981). Ship data concentrate on narrow routes employed by supply ships to antarctic stations and, moreover, do not cover the winter period.This note is to report on temperature observations in the surface layer above sea ice and open water from a set of drifting buoys deployed in July 1986 during the Winter Weddell Sea Project by R. V. Polarstern (Schnack-Schiel, 1987;Hempel, 1988). Up to nine stations were installed in the ice of the eastern Weddell Sea roughly between 60" and 68" S/5" E and 5" W. They carried sensors Boundary-Layer Meteorology 48: 293-297, 1989.