Cryosphere and Hydrology
Areal shrinkage of Arctic sea ice has been observed over the last 40 years, and its decline is proceeding faster than forecasted. These observed changes in the ice cover have impacts on the regional Arctic and sub-Arctic climate, environment, and ecosystems, and directly affect natural resource exploitation, marine transport and offshore operations, commercial fisheries, and indigenous lifestyles. Satellite monitoring offers continuous, near-total coverage of the Arctic ice pack. To enhance the retrieval of parameters describing ice conditions and to alleviate ambiguities in the interpretation of single satellite instruments, the demand for getting comprehensive sea ice information from multi-source satellite data obtained over the Arctic is growing as a result of climate change and its impact on environment and human activities. In this project, the overall objectives of our Sino-European sea ice research group are to upgrade and develop methodologies to retrieve quantitative sea ice information including measurements of ice area, thickness, drift velocity, and concentration using multiple satellite data provided by the EC Copernicus Earth Observation Program, ESA, ESA TPM, and Chinese satellites. The main multi-source satellite data will be combinations of Synthetic Aperture Radar (SAR), optical and infrared images, radar altimeter and passive microwave data. We also plan to assess the possibilities that new satellite missions offer for monitoring sea ice parameters, e.g. CFOSAT or future missions planned by ESA. In the project we will focus on five major research topics. 1. Sea ice type classification: The goal is to develop automated methods for operational ice charting and for achieving results with improved reliability and accuracy. 2. Sea ice thickness retrieval: We will port our algorithms developed for CryoSat-2/Sentinel-3 to HY-2A/B, and complement thickness estimation for thin ice using passive microwave data from SMOS, AMSR2, HY-2 and FY-3. 3. Sea ice drift and deformation retrieval: to this end we will use multi-frequency SAR image sequences and assess the usefulness of our results for regional studies of sea ice dynamics and its possible changes due to increasing temperatures in the Arctic. 4. Sea ice concentration estimation: We pursue to develop sea ice concentration retrieval algorithms for the Chinese passive microwave radiometers HY-2 and FY-3. 5. We will evaluate CFOSAT’s capability for sea ice detection. In our interest are also the Copernicus High Priority Candidate Missions (HPCMs) under discussion at ESA. The results expected from our proposed work will contribute to an improved understanding of impacts of climate change on sea ice dynamics, thus providing useful data for scientists, policy-makers and the general public. The project will demonstrate the benefits of combining Earth Observation data from European and Chinese satellites for operational mapping and interpretation of sea ice cover variations in the Arctic. As the only one sea ice remote sensing group under Dragon phases 2-4, our Sino-European team has cultivated an excellent and productive partnership and developed algorithms for sea ice types classification, retrieval of sea ice thickness, and drift in the Bohai Sea (China), supplemented by complementary studies for the Baltic Sea and the Arctic. This research is supported by the National Key Research and Development Program of China under grant 2016YFA0600102 and 2018YFC1407203, and the National Nature Science Foundation of China under grant 41976173 and 61971455. The European team members are on permanent positions and will support the Dragon Program by linking their national and international sea ice studies to the research topics listed above.
