Estimating Arctic Sea Ice Melt Pond Depth and Water Volume with Optical Satellite Imagery

Melt ponds frequently form on sea ice in the Arctic during the summer. Their albedo, much lower than ice and snow, amplifies the absorption of shortwave solar radiation in the Arctic. Consequently, precise estimation of melt pond depth (MPD) and meltwater volume is crucial for investigating Earth's energy balance and understanding climate change. In this study, a radiative transfer model is used to simulate the reflectance of sea ice and melt ponds. Subsequently, employing the dynamic pixel unmixing method, Sentinel-2 satellite imagery is used to estimate the depth and cover fraction of melt ponds, and then the volume of the water in melt ponds (MPV) can be calculated. Validation results indicate that compared to IceBridge and ICESat-2 data, Sentinel-2 estimates a melt pond fraction with an RMSE of approximately 10.2% and a melt pond depth with an RMSE of around 27.7 cm.