Glacier melt leads to more storms

The domino effect is clearly visible in nature. The record-breaking Antarctic ice loss in 2023 has led to an increase in storms over the ice-free Southern Ocean, according to a study published in the journal Nature. The work by Simon Josey, of the National Oceanography Centre in Southampton, UK, and his colleagues explores a still little-known aspect of the impact of shrinking ice: the transfer of heat from the ocean surface to the atmosphere. This phenomenon, which increases when the ice sheet does not fully recover during the winter, is accompanied by an increase in storms, according to the study, which combines analysis of satellite images of Antarctic ice, data on heat flows between the ocean and the atmosphere, as well as temperature and wind speed records. "Repeated episodes of such net sea ice loss in subsequent winters will reinforce this impact and are also likely to lead to profound changes in more distant areas, including the tropics and the Northern Hemisphere," the authors warn, calling for in-depth studies of the impact of these phenomena on the global climate system. In three areas particularly affected by the historic retreat of Antarctic sea ice in 2023, the researchers compared data collected during the southern winter with those observed during the winters of 1990-2015 (marked by relative stability in sea ice extent) and 2016-2022 (a phase of marked decline). In these regions, the reduction in sea ice extent reached up to 80% compared to the pre-2016 average and was accompanied by an increase in the redistribution of heat from the ocean to the atmosphere of up to a doubling. At the same time, the frequency of storms has increased compared to the period 1990-2015, sometimes with up to seven days marked by winds with an intensity of over 36 km/h during the winter of 2023.