LONG-TERM GOALS

The reduction of the sea ice coverage during the boreal summer will lead to an increased importance of wind waves for the dynamic processes of the Arctic Seas. The large ice free areas lead to longer fetch and thus longer and higher sea state. Wind waves will enhance upper ocean layer mixing, may affect the breakup of ice sheets, and will likely lead to increased coastal erosion. The primary long-term goal is a better understanding of the two-way interaction of waves and sea-ice, in order to improve wave models as well as ice models applicable to a changing Arctic wave- and ice climate. This includes observation and information retrieval from various data sources, in particular from spaceborne SAR imagery. Such retrieval methods of sea state in the MIZ will complement and validate model data for the spatial and temporal evolution of sea state in the MIZ. OBJECTIVES Over the ocean, synthetic aperture radar is capable of providing wind and wave information by measuring the roughness of the sea surface, as well as information on ice coverage. In particular, TerraSAR-X data have been used to investigate the highly variable wave climate in coastal areas (e.g. Lehner et al., 2013). However, the use of these data at the sea ice boundary is still to be utilized in full detail. In addition, TerraSAR-X data provide accurate estimates of the wind field over the ocean as well as the position (and change) of the ice edge, ice drift estimates, and ice floe size distributions. The main objectives of the proposed work are to adapt existing TerraSAR-X wave parameter and ice motion retrieval algorithms for the marginal ice zone in order to: • analyze the spatial and temporal variability of the wave field in the emerging ice-free regions; • investigate wave damping in sea ice and the related ice breakup