Reconstruction of Antarctic sea ice thickness from sparse satellite laser altimetry data using a partial convolutional neural network

The persistent lack of spatially complete Antarctic sea ice thickness(SIT) data at sub-monthly resolution has fundamentally constrained the quantitative understanding of large-scale sea ice mass balance processes.In this study, a pan-Antarctic SIT dataset at 5-day and 12.5 km resolutionwas developed based on sparse Ice, Cloud and Land Elevation Satellite(ICESat; 2003–2009) and ICESat-2 (2018–2024) along-track laser altimetry SIT retrievals using a deep learning approach.The reconstructed SIT was quantitatively validated against independent upward-lookingsonar (ULS) observations and showed higher accuracy than the other four satellite-derived and reanalyzed Antarctic SIT datasets. The temporal evolution of the reconstructed SIT wasfurther validated by ULS and ICESat-2 observations. Consistent seasonal cycles and intra-seasonal tendenciesacross these datasets confirm the reconstruction's reliability. Beyond advancing the mechanistic understanding of Antarctic sea ice variability and climate linkages, this reconstruction dataset's near-real-time updating capability offers operational value for monitoringand forecasting the Antarctic sea ice state.