Snow depth on Arctic sea ice derived from airborne radar measurements

• Main Authors: Jutila, Arttu, Ricker, Robert, Hendricks, Stefan, Paden, John, King, Joshua, Polashenski, Chris, Lange, Benjamin, Michel, Christine, Haas, Christian
• Format: Conference Object
• Language: unknown
• Published: 2019
• Subjects: Alfred Wegener Institute; Arctic; Arctic Ocean; Center for Remote Sensing of Ice Sheets (CReSIS); Chukchi; Greenland; Sea ice
• Online Access: https://epic.awi.de/id/eprint/50138/; https://epic.awi.de/id/eprint/50138/1/82A3306_Jutila_epic.pdf; https://hdl.handle.net/10013/epic.8a0fef52-f10e-4e71-a1d1-ed4503da796b

The snow layer on sea ice has high importance for polar climate as it affects heat, radiation, and fresh-water budgets. Additionally, snow loading is a critical parameter for the sea-ice freeboard-to-thickness conversion for satellite radar and laser altimeters. Despite its importance, there is a lack of snow observations spanning different spatial and temporal scales, thus introducing a significant source of uncertainty to altimetric sea-ice thickness retrievals. The ultra-wideband microwave radar (UWBM) Snow Radar, a 2–18 GHz airborne frequency-modulated continuous-wave (FMCW) radar developed by the Center for Remote Sensing of Ice Sheets (CReSIS) at the University of Kansas, can accurately detect the air/snow and snow/ice interfaces to measure snow thickness. Since 2009, an airborne Snow Radar has been operated onboard NASA’s Operation IceBridge (OIB) campaigns. In 2017, the UWBM Snow Radar was operated for the first time on an Alfred Wegener Institute (AWI) research aircraft, together with an airborne laser scanner for surface topography and freeboard measurements and an electromagnetic induction sounding instrument (EM Bird) to measure total ice thickness. The AWI airborne surveys operate at a low survey altitude (60 m a.g.l.) and slow aircraft speed, enabling fine-resolution mapping of the snow layer. Furthermore, the unique instrument setup on board the AWI research aircraft and the concurrent measurements of snow freeboard, total sea-ice thickness and snow depth allow us to directly investigate the freeboard-to-thickness conversion on regional scales for the first time. Here, we evaluate the performance of the radar installation and present radar-derived snow depth retrieved with a wavelet technique from recent airborne campaigns, PAMARCMiP2017 and IceBird winter 2019, over Arctic sea ice in the Greenland, Lincoln, Beaufort and Chukchi Seas and the central Arctic Ocean in March–April of the respective years.