Abstract's details
Cryosphere Applications for the SWOT SAR Interferometry and Altimetry
Event: 2025 SWOT Science Team Meeting
Session: Cryosphere: Lakes
Presentation type: Poster
The Cryosphere Applications for SWOT SAR Interferometry and Altimetry (CASSIA) project explores the potential of SWOT data to provide novel, advanced observations of the cryosphere. We explore SWOT data collected over cryosphere regions for the study of floating and grounded ice in both hemispheres. While the primary objectives of the mission focus on measuring ocean surface dynamics and terrestrial surface water storage, the possibilities to use SWOT's innovative payload to improve satellite measurements over the Polar Regions have been clear from early SWOT data onwards.
This study compares SWOT data at C-, Ku- and Ka-band frequencies and the V- and H polarisations from both SWOT's interferometer and altimeter instruments over both sea ice and land ice. Over sea ice we show that retrieved range differences between the nadir C- and Ku-band altimeters are ~constant over leads but highly variable over sea ice, indicating variable scattering depths. These scattering depths and especially their variability are difficult to observe in non-spatially-coincident altimeters i.e. on separate platforms, making SWOT an ideal mission for this intercomparison. Using intercomparisons between nadir altimeter and KarIn datasets, we are able to indicate that the nadir altimeters pick up leads and floes reliably and that retrieved freeboards show a strong frequency dependence. Similar to our study over sea ice, over land ice we compare SWOT KarIn and nadir altimeter data, observing characteristics of the radar penetration and scattering over ice sheets and ice shelves, showing results over Antarctic and Greenland. the implications of the physics revealed by SWOT and the implications for retrieval of Essential Climate Variables will be highlighted.
We show SWOT's unique capability to make spatially and temporally coincident measurements both for geophysical observations of Essential Climate Variables. We also contextualise our findings and show how these are relevant for both planning of novel concept missions (e.g. PoSARA) and interpretation of data from other existing missions (e.g. CryoSat) including missions approaching launch (e.g. CRISTAL). We summarise the status, outlook and suggestions for development in relation to SWOT data products over the cryosphere.
Back to the list of abstractThis study compares SWOT data at C-, Ku- and Ka-band frequencies and the V- and H polarisations from both SWOT's interferometer and altimeter instruments over both sea ice and land ice. Over sea ice we show that retrieved range differences between the nadir C- and Ku-band altimeters are ~constant over leads but highly variable over sea ice, indicating variable scattering depths. These scattering depths and especially their variability are difficult to observe in non-spatially-coincident altimeters i.e. on separate platforms, making SWOT an ideal mission for this intercomparison. Using intercomparisons between nadir altimeter and KarIn datasets, we are able to indicate that the nadir altimeters pick up leads and floes reliably and that retrieved freeboards show a strong frequency dependence. Similar to our study over sea ice, over land ice we compare SWOT KarIn and nadir altimeter data, observing characteristics of the radar penetration and scattering over ice sheets and ice shelves, showing results over Antarctic and Greenland. the implications of the physics revealed by SWOT and the implications for retrieval of Essential Climate Variables will be highlighted.
We show SWOT's unique capability to make spatially and temporally coincident measurements both for geophysical observations of Essential Climate Variables. We also contextualise our findings and show how these are relevant for both planning of novel concept missions (e.g. PoSARA) and interpretation of data from other existing missions (e.g. CryoSat) including missions approaching launch (e.g. CRISTAL). We summarise the status, outlook and suggestions for development in relation to SWOT data products over the cryosphere.