What shrinking Arctic ice means for summers in the U.S
Thirty years of shrinking Arctic sea ice has boosted extreme summer weather, including heat waves and drought, in the United States and elsewhere, according to a study published on Dec. 8 in the journal Nature Climate Change.
The new study — based on satellite tracking of sea ice, snow cover and weather trends since 1979 — links the Arctic’s warming climate to shifting weather patterns in the Northern Hemisphere’s midlatitudes.
“The results of our new study provide further support and evidence for rapid Arctic warming contributing to the observed increased frequency and intensity of heat waves,” said study co-author Jennifer Francis, an atmospheric scientist at Rutgers University in New Jersey.
Weakened jet stream
Changes in the Arctic can perturb midlatitude weather in such regions as the United States, Europe and China because temperature differences between the two zones drive the jet stream, the fast-moving river of air that circles the Northern Hemisphere, explained lead study author Qiuhong Tang, an atmospheric scientist at the Institute of Geographic Sciences and Natural Resources Research in Beijing.
“As the high latitudes warm faster than the midlatitudes because of amplifying effects of melting ice, the west-to-east jet-stream wind is weakened,” Tang told LiveScience in an email interview. “Consequently, the atmospheric circulation change tends to favor more persistent weather systems and a higher likelihood of summer weather extremes.”
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