The Linkage Between Arctic Sea Ice and Midlatitude Weather: In the Perspective of Energy

Abstract

The influence of Arctic changes on the weather in the highly populated midlatitude is a controversial topic with little agreements regarding its existence or its mechanism. Utilizing eddy energy as metrics of circulation and temperature fluctuations with weather patterns, this study highlights the robust relationship between the early autumn Arctic sea ice and the wintertime transient activities over northern Eurasia on interannual time scale, by comparing groups of statistical and diagnostical results. With the reduction of sea ice in early autumn in Barents, Kara, Laptev, and East Siberia Seas, the atmosphere over those polar regions exhibits significant increase in eddy energy in the following winter. In the adjacent Eurasia, the wintertime synoptic eddy energy decreases, while the low-frequency eddy energy, corresponding to persistent weather patterns, exhibits evident and dominant increase. The enhanced southward energy propagation of low-frequency waves from the polar region to the north of middle-to-east Asia suggests a mechanism for the Arctic-midlatitude linkage, indicating that Arctic sea ice could be a source of predictability for both extended-range and subseasonal to seasonal forecasts.