A Fram Strait cyclone: Properties and impact on ice drift as measured by aircraft and buoys



[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−1 toward 200° but increased to 0.6 ms−1 during the cyclone passage. The ice drift amounted to 1.6% of the geostrophic wind with a turning angle of 51° on 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.