Some parts of northern Eurasia have been witnessing increased snow cover over the past decades, even as rising air temperatures are already melting glaciers and polar ice caps in an interesting paradox. Researchers have now shown these two are related.
Global warming has increased the evaporation and retreat of sea ice in the Arctic Ocean. The climate change-induced impacts in the Arctic Ocean could be responsible for an increase in snow cover in Siberia, a new study published in the journal npj Climate and Atmospheric Science stated has suggested.
Enhanced evaporation deposits more moisture in the Arctic atmosphere, which makes its journey towards Siberia. These events have substantially increased from autumn to early winter during 1981-2019, the study stated.
The Arctic has warmed nearly four times faster than the rest of the world over the past 43 years, a previous study found. The impacts are being felt in mid-latitudes, where it could make extreme weather events more likely, scientists warned.
“Climate change observed recently in mid-latitude regions might reflect the effect of Arctic change,” Tomonori Sato, faculty of Environmental Earth Science at Hokkaido University, told Down To Earth.
Sato and colleagues wanted to understand what was driving excess snowfall in western Russia. They used a computer modelling technique to quantify how much water vapour evaporated from the Arctic Ocean.
They also investigated how moisture moved to northern Eurasia, particularly Siberia, during recent decades. Water evaporation from the Arctic Ocean has increased over the past four decades, the analysis showed.
The most impacted were Barents, Kara, Chukchi and East Siberian Seas between October and December. “These areas experienced sea ice loss in recent decades. The areas with increased evaporation mostly coincide with the area with sea ice retreat,” Sato said.
Moisture from the Arctic travelled over western parts of Siberia, the model showed. The researchers recorded a high concentration of Arctic moisture, especially in August. This, according to them, corresponded with years of strong southward-moving moisture.
This movement became dominant after around 1995, the researchers wrote in the study. Further, the model picked up another feature: Evaporation in the Arctic Ocean and snowfall in Siberia were especially strong during cyclonic events.
These weather events pick up unusually large quantities of moisture south and transport them into Siberia, the findings suggested.
This study can help improve predictions of abnormal weather events such as heatwaves, which increase the risk of forest fires, Sato and his colleagues stated.
Increased snow cover in western Russia increased the risk of summer heat waves in Europe and Northeast Asia, Sato and his colleagues found in an earlier study.
More work needs to be done as the Arctic region is very complicated and is less known, Sato said. “Better understanding of the dynamics of Arctic change is expected to help understand the climate change occurring in other areas of the Earth,” he added.