Detection of Melt Ponds on Arctic Summer Sea Ice From ICESat‐2
Rachel Tilling, N. T. Kurtz, Marco Bagnardi, Alek Petty, R. Kwok
Abstract
Abstract Hemisphere‐wide observations of melt ponds on sea ice are needed to understand their influence on the surface radiation budget of the Arctic Ocean and to extend the satellite sea ice thickness data record. Here we present a first assessment of NASA's Ice, Cloud, and land Elevation Satellite‐2 (ICESat‐2) over individual Arctic sea ice melt ponds with different reflective properties. We use coincident high‐resolution satellite imagery from WorldView‐2 and Sentinel‐2 over different sea ice topographies to show that smooth ponds are highly reflective and can saturate the ICESat‐2 photon detection system. Rougher ponds have a more varied backscatter signal, and in some cases both the water and underlying ice surfaces are visible in photon height distributions. Characterizing the complex photon backscatter signals of melt ponds on sea ice is a first step toward automating retrievals of pond parameters such as width, melt pond fraction and depth, and improving higher‐level ICESat‐2 sea ice height and freeboard products.