Cassie Stuurman (Jet Propulsion Laboratory, California Institute of Technology, United States); Sara Fleury (Laboratoire d'Etudes en Géophysique et Océanographie Spatiales, Centre National de la Recherche Scientifique (LEGOS/CNRS), France); Mohammed Dabboor (Science and Technology Branch, Environment and Climate Change Canada, Government of Canada, Canada); Laurie Padman (Earth and Space Research, United States); Susan Howard (Earth and Space Research, United States); Zachary Katz (Department of Geophysics, Colorado School of Mines, United States); Sonam F. Sherpa (Institute at Brown for Environment and Society, Brown University/School of Environment, Society, and Sustainability, University of Utah , United States); Ellianna Abrahams (Department of Geophysics and Stanford Data Science Institute, Stanford University, United States); Matthew R. Siegfried (Department of Geophysics, Colorado School of Mines, United States); Imogen Garlick (UCL Department of Space & Climate Physics, United Kingdom); Rosemary Willatt (UCL Department of Earth Sciences, United Kingdom); Felix L. Müller (Deutsches Geodätisches Forschungsinstitut (DGFI-TUM), TUM School of Engineering and Design, Technical University of Munich, Germany); Antonio Bonaduce (Nansen Environmental and Remote Sensing Center (NERSC) , Norway); Andrew Thompson (Environmental Science and Engineering, California Institute of Technology , United States); Camryn Kluetmeier (Department of Earth, Marine, and Environmental Sciences, University of North Carolina at Chapel Hill, United States); Pierre Rampal (Institut de Géophysique de l'Environnement, Centre National de la Recherche Scientifique (IGE/CNRS), France); Khalil Bakhtiari Asl (Centre Eau Terre Environnement, Institut National de la Recherche Scientifique, Canada); Sahra Kacimi (Jet Propulsion Laboratory, United States)

The SWOT mission launched in December 2022 with the goals of delivering the first global inventory of Earth's surface water, high-resolution ocean topography, and temporal variability of water bodies. Although SWOT’s primary objectives targeted terrestrial hydrology and oceanography, SWOT’s ~78° latitude orbital turnaround results in up to sub-weekly observations, unaffected by clouds, in many critical polar regions. SWOT may, therefore, also make significant contributions to cryospheric science. To capitalize on this potential, a dedicated Cryosphere Working Group was formed from the 2024 Science Team to explore and expand SWOT’s cryospheric applications. The group’s early efforts yielded the first high resolution (HR) tasking over Antarctica, adding to HR acquisitions for other key Arctic regions. Other promising advancements include a demonstration that KaRIn backscatter enables robust discrimination between sea ice and icebergs, a long-standing challenge for automated classifiers, and that the combination of sea surface height anomaly (SSHA) and backscatter supports a novel SWOT-based classification of sea ice and leads. A preliminary examination of SWOT LR data against ICESat-2 provides confidence in the feasibility of retrieving the first truly two-dimensional estimates of sea ice freeboard. SSHA observations of the Antarctic coastal margin provide, for the first time, the potential to observe variability of major surface currents across multiple timescales. HR data also provide the first frequent repeats of the 3-D structure of rifts on some Antarctic ice shelves. Additionally, the initial assessment of SWOT observations offers valuable insights into the mission’s potential for monitoring freshwater ice. Preliminary comparisons of HR PIXC data with two days of concurrent DEMs collected over river ice show ice surface elevation differences of ~25 cm. For each of these applications, however, significant challenges remain. Errors in geoid, mean sea surface, and tide corrections, and ongoing issues with crossover corrections hinder the retrieval of accurate coastal SSHA values. For ice shelves, our initial studies of HR data reveal many regions where measured elevations experience jumps, some of which may be attributed to errors in the underlying digital elevation model (DEM) from changing ice shelf fronts and rifts, and from large voids in the v1.1 100m REMA DEM. Artifacts in both HR and LR products, combined with complications introduced by onboard and ground-based processing pipelines, present further obstacles to retrieving reliable surface heights in polar regions. Ongoing work aims to resolve these issues — taking advantage of collaborations with other working groups — and establish SWOT as a powerful tool for observing cryosphere processes.