Scientists have discovered the cause of extreme winter weather in the Northern Hemisphere.
Scientists from the Department of Environmental, Earth, and Atmospheric Sciences at MIT, along with colleagues from the Hebrew University of Jerusalem, in a new work studied how the stratospheric polar vortex has changed over the past forty years.
A polar vortex is an area of high winds high in the atmosphere that traps cold air around arctic regions. Researchers have found a direct link between rapid warming in the Arctic and its consequences, so sea ice began to shrink, while snow cover in Eurasia, on the contrary, increased.
A typical polar vortex has the shape of a circular circulation cell, but it has recently acquired an extended shape: the authors decided to find out the reasons for this process.
During the study, the authors tracked how this process took place. They found that the excess energy of the Eurasian wave is reflected from the polar vortex and absorbed by a similar North American wave with high pressure over Alaska and the North Pacific Ocean and low pressure over eastern North America. Therefore, due to the energy of the two waves, the likelihood of extreme temperature and weather conditions increases.
Last winter, a severe cold wave in Texas sparked controversy over whether climate change could contribute to harsher winter weather. However, there has been no research to support or disprove a physical link between climate change and the cold wave in Texas and other recent severe winter weather events in the United States. Our research provides compelling evidence for this link and shows that global warming will not protect us from the ravages of a harsh winter.
Jude Cohen, Study Lead
According to the results of the work, the authors note that their work helps to resolve the long-standing contradiction between the increase in extreme frosts in winter in mid-latitudes and, at the same time, the rise in global temperatures.
The climate in the Arctic has changed dramatically over the past three years, with a rapid rise in temperature, melting of sea ice, a decrease in spring, and an increase in autumn snow cover.