Union Glacier in the Ellsworth Mountain Range drains its mass to the Ronne-Filchner Ice Shelf. Mean surface mass balance (SMB) estimates range between 0.16 and 0.33 m water equivalent (w.e.) a- 1 depending on site location and method. However, these observations are not representative of the high spatial variability in snow deposition dynamics caused by relief, wind transport-driven accumulation, and high sublimation rates. A better understanding of these processes is required to improve SMB estimates in the region of Ellsworth Mountains. In this study, we use an approach based on geospatial data (COSMO-SkyMed SAR, high-resolution TanDEM-X-derived products) and field measurements in a cluster analysis to identify and delimit zones with distinct accumulation characteristics. In general, wind-exposed areas have larger snow grains, faceted forms because of longer temperature-gradient exposure, more layers and greater hardness, whereas wind-protected areas have higher accumulation rates.