Antarctic Snowfall Patterns and Trends: A Regional Analysis Across Multiple Data Sets

Abstract

Snowfall is the dominant positive component of the Antarctic surface mass balance (SMB) and a key factor regulating global sea level. However, substantial uncertainty remains in its spatial distribution and long-term variability due to sparse in situ observations and retrieval challenges over polar ice sheets. This study evaluates Antarctic snowfall patterns and trends using multiple data sets, including satellite-based products (Global Precipitation Climatology Project (GPCP) V3.3, IMERG V7), atmospheric reanalyzes (MERRA-2, ERA5), and CloudSat radar retrievals as an observational benchmark. To better examine spatial heterogeneity and regional variability, the Antarctic domain is subdivided into six regions: East and West Antarctica, coastal and inland zones, the high plateau (elevation ≥2,250 m), and lowland areas (<2,250 m). CloudSat comparisons show that GPCP, MERRA-2, and ERA5 reproduce the large-scale spatial and seasonal snowfall patterns, whereas IMERG severely underestimates accumulation. During 2000–2024, GPCP and ERA5 both exhibit statistically significant positive snowfall trends, while MERRA-2 shows no statistically significant change. Regional and grid-point analyses reveal coherent positive trends across East Antarctica, and localized coastal regions. Overall, the results indicate a modest but spatially consistent increase in Antarctic snowfall during 2000–2024, in line with enhanced atmospheric moisture transport under a warming climate, with implications for understanding the evolving Antarctic SMB and its contribution to sea-level change.