Sea ice dynamics observed by ERS-2 SAR imagery and ARGOS buoys in Storfjorden, Svalbard

The Storfjorden sea ice cover has been observed during two winters 1997 to 1999 using ERS-2 synthetic aperture radar. This region presents high sea ice dynamics by forming polynyas under northerly winds. Using the ice tracking method of nested correlation between two images separated by three days, the authors obtain a high-resolution displacement field of the sea ice cover. In spring 1999, several ARGOS buoys were deployed on ice floes to provide ground truth measurements, which were compared with wind data from Hopen Island and the deformed grid resulting from the displacement field. A velocity field, shear zones and a divergence field can be extracted as enhanced images. Together with the original SAR image and an image corresponding to the correlation coefficients for each grid node, a supervised sea ice classification into fast ice, pack ice and polynya is performed.