Changes in Arctic winds are allowing warm fronts further north and could spell trouble in the south across North America and Europe.
A NOAA-led study observed the previously normal west-to-east flow of high altitude winds in the Arctic summer have been replaced by currents undulating north and south. Cold Arctic air is being pushed further south, while warmer air subsequently reaches further north in the the new wave-like north and south pattern.
“Our research reveals a change in the summer Arctic wind pattern over the past six years,” James Overland, a NOAA research oceanographer and leader of the study in a press release. “This shift demonstrates a physical connection between reduced Arctic sea ice in the summer, loss of Greenland ice, and potentially, weather in North American and Europe,”
Before 2007, summer winds blew generally from the west, helping to keep cold air in the Arctic. However, winds are now whipping north through the Bering Straits. Those winds bring warmer Pacific temperatures into the north. The gusts also push icebergs south into the Atlantic.
Changing winds contributes to the record-breaking disappearance of summer sea ice in the Arctic this year. Besides thawing parts of Earth’s cryosphere, the changing wind currents could impact weather over the United States and western Europe. Heavy snowfall, heat waves, and flooding in North America and Europe may result, but where, when and how is largely unpredictable.
“What we’re seeing is stark evidence that the gradual temperature increase is not the important story related to climate change; it’s the rapid regional changes and increased frequency of extreme weather that global warming is causing,” said co-author Jennifer Francis of Rutgers. “As the Arctic warms at twice the global rate, we expect an increased probability of extreme weather events across the temperate latitudes of the northern hemisphere, where billions of people live.”
The study was published in Geophysical Research Letters.
IMAGE: The Arctic (Jeff Schmaltz, NASA Earth Observatory)