Jet Stream’s Migration North Could Mean More Droughts in U.S.

by Matthew Memrick
(Photo by Terry Pierson, The Press-Enterprise/SCNG)

A recent study says the polar jet stream is moving north, which could spell more future droughts and disasters for the United States.

Business Insider reported on the University of Arizona’s Climate Systems Center’s work. 

The center said the jet stream’s normal range could be out of wack by 2060 if greenhouse gases continue to build.

Jetstream Under Threat

A jetstream, or fast-flowing air current, moves weather over the Earth. The polar jet stream moves over the northern hemisphere in circles, floating nine miles in the sky. It primarily separates the hot air from the cold. It transports weather from West to East across the United States, the Atlantic Ocean, and Europe. Not only does it do that, but it also controls the rain and warmth these places get.

Researcher and study co-author Matthew Osman said the northern migration may have already begun. When the jetstream starts to move north, weather in the northern hemisphere will change. That means many can expect more droughts and heatwaves to southern Europe and the eastern U.S. Also, European and Scandinavians will see more rain and flooding in the northern parts of their areas.

Why The Migration?

Rising air temperatures mess with the North Atlantic jet stream’s two main forces: warm tropical air and Arctic cold air.

With the Arctic region warming twice as fast as the rest of Earth, warm air heads further north to find colder air. When that happens, the jet stream has to move with those two forces.

Osman and researchers know the jet stream’s location is wild and constantly changing. But his center’s looked at its location over the last 1,250 years, thanks to ice core samples on the Greenland Ice Sheet. Those go back to the 8th century and could show the amount of fallen snow and when the snow fell.

From those samples and climate models, the study was able to predict how the jet stream would move over the next four decades with the current rate of greenhouse-gas emissions.

Folks, the results were not pretty. The jet stream’s shift under that pressure went past any previous change. So, messing with the jet stream, Osman said we could make “severe climate risks more likely in our future.”

East Coast Heat Coming, Artic Ice A Factor

The research suggests more heat in the eastern United States and more drought and heatwaves in North America and Europe in the future.

Osman said Europe would feel it worse because it’s on the end of the North Atlantic jetstream. Southern Europe would get drier while Northern Europe could see wetter, milder weather. That also means more flooding like Europe has seen this year.

Some researchers think the warming will change the jet stream more than it has been. 

But, you’ve got to factor in the melting Arctic sea ice, as another study did last month.

With the heat melting the sea ice, additional heat and moisture from the Earth’s surface move toward space. The jet stream, in turn, pushes extreme cold air toward the equator. That causes a ripple effect that messes with the jet stream.

What will happen? Intense winter storms and cold snaps. Think Texas in 2019 when residents lost power in February. Osman said an increased jet stream waviness could make polar vortex events “more frequent.”