Atmospheric and Environmental Research
), a Verisk Analytics (Nasdaq:VRSK) company, reports some of the strongest evidence to date that Arctic sea ice loss, which contributes to an overall warmer Arctic, has links to colder winters and related extreme weather events across northern Eurasia and much of the U.S. and Canada.
In research published yesterday in
magazine, AER scientists investigate the cause for a recent string of cold winters. The findings present a previously missing piece in the quest to understand if declining sea ice is influencing more extreme weather, including colder, snowier winters. The research may also lead to more accurate forecasts of temperatures and storms that are used by the private and public sectors in preparation for the winter season.
The research shows that the “Warm Arctic/Cold Continents” temperature pattern follows autumns with less Arctic sea ice and increased Siberian snowfall. The pattern is also associated with the negative phase of the Arctic Oscillation, which is the dominant atmospheric pattern observed during severe winters and comprises a weakened jet stream and more cold air intrusions southward from the Arctic into North America and Eurasia.
“This research shows for the first time how both sea ice melt and rapid snow advance are related to more severe winter weather,” Judah Cohen, Ph.D. principal scientist and director of seasonal forecasting at AER, who is lead author of the study. “The results suggest that record sea ice melt last autumn contributed to the individual extreme weather events of last winter. Using a statistical rather than dynamical model, we established the relationship between declining sea ice, more extensive snow cover in northern Eurasia, and a weakened polar vortex, which allows cold air normally confined to the northern latitudes to spread southward.”
“During this time of rapid change in the Arctic climate system and our understanding of it, the scientific community must look closely at the observational record, be open-minded in considering alternative hypotheses, and not be too quick in dismissing hypotheses that do not conform with the expectations of existing models,” said Charles H. Greene, associate editor of
and director of the Ocean Resources and Ecosystems Program at Cornell University. “This paper takes that perspective, and that is why it’s valuable and timely. The AER scientists took a different approach to reframe the question and, as a result, they demonstrate that snow cover in Asia and Arctic sea ice are related and key to understanding our recent streak of colder winters.”
“We applied the same analytical tools to sea ice that were used to demonstrate the link between Siberian snow cover, the Arctic Oscillation, and mid-latitude weather,” said Jason C. Furtado, Ph.D., staff scientist at AER and co-author of the paper. “These preliminary findings provide an additional framework to understand the important connection between the Arctic and the mid-latitudes, which subsequently can be used for predictions of the fall and winter months.”