Asymmetric distribution of Pan-Antarctic snowmelt under changing Climate: In perspective of natural climatic events and marine biology

Abstract

Understanding global climatic changes resulting from global warming and their impact on polar snowmelt and ocean biogeochemistry requires an assessment of the spatio-temporal variability of surface ice melt over the Antarctica region. Even though various studies have been carried out on the ice melts in the Antarctica region, there is a lack of studies related to biophysical (temperature and chlorophyll-a) parameters and El Niño-Southern Oscillation (ENSO) influences in the Antarctica region. To address this problem, the present study assessed the ice melt and its impact on the Antarctica region from 2002 to 2021 using satellite-derived products of sea surface temperature (SST), chlorophyll-a (Chl), and snowmelt. After analyzing the data, it shows that larger ice shelves like Larsen, George VI, Brunt, Riiser-Larsen on the western side and Shackleton, West, and Totten on the eastern side are showing higher snowmelt than usual in a strong La Niña year (2010–2011) (ENSO index greater than −1.5 for austral summer months), while other ice shelves are showing a reduction in snowmelt. The Abbott ice shelf and parts of the Larsen and Ross ice shelves on the western side experienced higher snowmelt during a strong El Niño year (2015–2016) (ENSO index greater than + 1.5 for austral summer months). In contrast, inner land areas adjacent to the ice shelves experienced higher than usual snowmelt. Also, results revealed a significant increase in Chl from the open ocean towards the Antarctica continental shelf, where SST values are decreasing towards the shelf.Moreover, the present study provides critical information on the effect of ENSO on snowmelt and the impact of snowmelt on Chl and SST under changing climate conditions.