Inter‐Comparison of Snow Depth Over Antarctic Sea Ice From Ocean Reanalyzes and Observations

Abstract

Snow depth on Antarctic sea ice is a critical climate variable affecting energy and mass balance, yet its observation and modeling remain challenging. We present a systematic intercomparison of snow depth from six ocean reanalysis products, two satellite retrievals, and ship‐based and airborne observational constraints. Results indicate that reanalysis and satellite products show consistent large‐scale climatological snow depth patterns, with the highest depths in the Weddell Sea. However, substantial differences remain in magnitude, seasonal phasing, spatial variability, and trends. The multi‐model mean agrees with satellite‐derived products in some integrated metrics, but tends to smooth regional features and may reflect compensation among reanalysis members. The sensitivity of simulated snow depth to atmospheric forcing and simplified snow processes highlights current limitations in representing wind redistribution and snow‐to‐ice conversion. Improved observations and model physics are needed to better constrain Antarctic sea‐ice snow depth.