The Dynamic Processes of Sea Ice on the East Coast of Antarctica—A Case Study Based on Spaceborne Synthetic Aperture Radar Data from TerraSAR-X

摘要

In early January 2014, the Chinese icebreaker XueLong was stopped by thick ice on its passage to rescue the trapped Russian vessel Akademik Shokalskiy along the east coast of Antarctica, between Commonwealth Bay and the Mertz Glacier. During the event, X-band spaceborne synthetic aperture radar (SAR) data were continuously acquired from the TerraSAR-X (TS-X) satellite to monitor the state of the sea ice to assist both vessels. The emphasis of this case study is not to understand how the vessels escaped danger but rather to investigate the sea ice breaks in the region, i.e., the dynamic processes of the sea ice during the event through an analysis of the TS-X data, sea ice classification, and the reanalysis of surface wind and ocean current modeling results. Therefore, we present six images of TS-X ScanSAR and newly operational wide ScanSAR imaging modes; these images provide abundant information about the state of the sea ice. Both the ScanSAR and wide ScanSAR images in the HH-polarization are used for classifying sea ice in the region; the resulting classification illustrates how the sea ice varied and finally broke during the event. A further analysis of the sea ice drift derived from the sequential TS-X images and surface wind and ocean current model data partially explains why the sea ice broke under such weather conditions. This case study contributes to a better understanding of the sea ice dynamics on both regional and local scales.