Flexural strength of Arctic sea ice using spaceborne polarimetric SAR data

Abstract

Flexural strength of sea ice is the applied stress just before yielding and has been used in ship resistance test because icebreakers and ice-strengthened vessels break sea ice mostly by bending, weighting down on ice sheets. The flexural strength can be expressed as a brine volume fraction which strongly depends on salinity of sea ice. In this study, we try to develop an algorithm of extracting the flexural strength of sea ice using dual-polarimetric Sentienl-1 SAR data and salinity measurements from the sea ice cores. The depolarization ratio of HH and HV polarization over the first year sea ice was sensitive to the bulk salinity which was measured from the cruises of the icebreaker Araon of Korea Polar Research Institute. The flexural strength of Arctic sea ice in the marginal zone in the north of Chukchi Sea and in the west of Beaufort Sea was estimated using the depolarization ratio of Sentinel-1 data. The results showed higher flexural strength for older ice when compared with the sea ice age map, which is distributed by NSIDC. The flexural strength of sea ice is expected to have commercial, navigational, and scientific contribution by providing near-real time sea ice information to the vessels and being used as a new sea ice index for monitoring climate changes.