A Study on Summer Surface Temperature of Antarctic Ice Shelves Based on FY-3 Satellite: A Case Study of the Getz and Amery Ice Shelves

The Getz Ice Shelf is a region of high surface melt potential, yet its annual melt days are typically fewer than 10. In contrast, the upstream region of the Amery Ice Shelf, which has similar latitude and altitude, is more prone to surface melting, with some areas recording over 50 melt days throughout the year. Ice surface temperature (IST) is a critical indicator of its surface energy budget and mass balance. To investigate the differences in IST between the Getz and Amery ice shelves, this study employed high-resolution thermal infrared data from the FY-3A MERSI-Ⅰ and FY-3D MERSI-Ⅱ satellites to retrieve summer IST over both ice shelves for 2008–2014 and 2019–2024, and conducted a comparative analysis of their spatiotemporal variation patterns. Time series analysis of the Getz Ice Shelf revealed no statistically significant IST trend in either period. However, an anomalous warming event exceeding 5 K was observed in March 2013, abruptly reversing the typical seasonal cooling and resulting in a higher monthly average IST for March than for February. Meteorological analysis linked this anomaly to an anticyclone in the Amundsen Sea, which drove strong poleward transport of moisture and heat. The consequent increase in mid- and low-level cloud cover enhanced downward longwave radiation, leading to rapid surface warming. Also for the Amery Ice Shelf, time series analysis revealed no statistically significant IST trend in either period. Comparative analysis of summer IST reveals similar average values for the Getz and Amery ice shelves, with Getz even warmer by nearly 2 K in some years. However, surface melting on Getz remains lower. Analysis incorporating precipitation data indicates that the Getz Ice Shelf receives significantly higher precipitation than the Amery Ice Shelf. The greater snowfall replenishes surface fresh snow, increases albedo, and thereby suppresses melting. This suggests that wet ice shelves surface with high accumulation have a higher temperature threshold for surface melting. Notably, surface precipitation over the Getz Ice Shelf during the summer warming period (October–December) showed a significant declining trend from 2012 to 2023. Given the absence of pronounced changes in IST, this reduction in precipitation may elevate the future risk of surface melting on the Getz Ice Shelf.