Cold spells linked to melting Arctic sea ice in northern Eurasia

When someone asks you why it’s so cold outside, you can tell them its global warming. The paradox is scientifically sound, backed by a new research from University of Tokyo, published in Nature Climate Change, that finds a correlation between climate change and extreme cold spells.

Global warming has caused sea-ice that usually covers the Arctic to melt, which releases more heat into the atmosphere. This heat affects the jet streams in the Arctic and directs cold air south towards northern Europe and Asia, explains Dr. Masato Mori, the lead researcher on the study. The result is an extreme period of cold across the northern Eurasian area.

This heat released from the sea-ice can impact both moderation and direction of jet streams in the Arctic, Dr. Mori said. His study found that most current models of looking at air circulation underestimate the effect that melting sea-ice has on these cold weather spells.

“Sea-ice basically provides an insulating barrier between the heat in the ocean and the atmosphere,” Dr. Robel Alexander, Assistant Professor at Georgia Tech’s School of Earth and Atmospheric Sciences and area expert, said. When the barrier of ice is gone, heat is drawn up into the atmosphere.

Researchers are just now studying whether similar phenomena impact how the Polar Vortex brings cold air down to the northern United States, like what Chicago experienced the last week of January.

“The linkage between sea-ice and the Polar Vortex is not yet clear,” Dr. Mori said. “Many researchers are conducting studies right now [on the topic]”

Dr. Mori’s research looks at the Siberian High, a cold air system that contributes to Eurasia’s cold temperatures. He has found that this system may work as a series of impacts. Melting sea-ice in the Arctic intensifies the Siberian High. This amplified Siberian High, Dr. Mori explains, can weaken the Polar Vortex, causing it to bring a cold spell over North American.

“The Polar Vortex is an anti-clockwise circulation in the stratosphere,” Dr. Mori said. “Sometimes the stratosphere weakens by effects from the troposphere. The Siberian High is one of the factors that affects the strength of the Polar Vortex.”

Basically, the same systems that cause cold spells in Eurasia could contribute to cold spells in North America. When humanity suffers from extreme cold it does so together.

There is still more research to be done on the Polar Vortex and North American temperature impacts. The relationship between melting Arctic sea ice and colder Eurasian temperatures also requires more in-depth analysis.

Dr. Robel said that he does not believe there is a clear consensus in the climate community about the connection between melting sea-ice and extreme cold weather.

“There are definitely proponents on both sides,” Dr. Robel said. “It’s still a very active area of research.”

According to Dr. Mori, however, the correlation of melting sea-ice and cold snaps may be irrelevant in a century or so. The heat caused by global warming would overcome the power of any cold snap.