Cyclones in the Arctic are becoming more violent and frequent

CHICAGO – In January 2022, the cycle recreated a large area covered by ocean ice between Greenland and Russia. Violent storms churned up 8-meter-long waves that battered the region’s poor sea ice flotillas, while hot rain bombarded and sweltering southerly heat from the air.

Six days after the attack began, about a quarter, or about 400,000 square kilometers, of a vast area of ​​sea ice disappeared, leading to a record week of loss in the region.

The strongest storm of the arctic cycle ever recorded. But don’t hold the title too long. Cyclones in the Arctic have become more frequent and more intense in recent decades, posing dangers to sea ice and people as well as people, researchers reported at the December 13 meeting of the American Geophysical Union. “This trend is expected to continue as the region warms rapidly in the future,” says climate scientist Stephen Vavrus of the University of Wisconsin-Madison.

Rapid Arctic warming and more destructive storms

The Arctic Circle is warming about four times as much as the rest of the Earth (SN: 8/11/22). A major driver of sea ice loss is human-caused climate change. Floating ice reflects far more solar radiation into space than bare oceans do, influencing global climate (SN: 10/14/21). In August, the heart of the sea ice melting season, cyclones were observed to amplify the average sea ice losses, exacerbating the warming.

More there: Just as hurricanes can depopulate southern regions, boreal vortices can threaten people living in and traveling to the Arctic (SN: 12/11/19). As hurricanes increase, “stronger winds create a risk to marine navigation through higher waves,” Vavrus said, “and to sea erosion, which has already become a serious problem throughout much of the Arctic and has forced some communities to move inland.”

Climate change is increasing storms further south (SN: 11/11/20). But it is uncertain how arctic cyclones will change as the world warms. Some previous research has suggested that, on average, the pressures on the cores of Arctic cyclones have fallen in recent decades. That would be difficult, as lower pressures usually mean more intense storms, with “stronger winds, greater temperature variations and heavier rainfall. [and] snow,” said atmospheric scientist Xiangdong Zhang of the University of Alaska Fairbanks.

But inconsistencies between the analyzes prevented a clear trend from emerging, Zhang said at the meeting. He and his colleagues then compiled a record, from 1950 to 2021, of the arctic lion cycle, its intensity and duration.

Arctic cyclone activity has increased in strength and frequency in recent decades, Zhang reported. Pressures in the cores of today’s boreal vortices are on average about 9 millibars lower than in the 1950s. For context, such a change in pressure is roughly equivalent to the bumping of a powerful Category 1 tornado well into Category 2 territory. And vortices became more frequent during the winters in the North Atlantic Arctic, and during the summers in the North Arctic Eurasia.

What’s more, August hurricanes appear to be more damaging to sea ice than in the past, said astronomer Peter Finocchio of the Naval Research Laboratory in Monterey, Calif. He and his colleagues compared the response of the Arctic sea ice to the summer cycles of the 1990s and later years. the 2010s.

August vortices in the latter decade have been followed by a 10 percent loss of sea ice in the area on average, down from a 3 percent loss on average in previous decades. This is possible, in part, as warm water is poured in from below, which can dissolve the ice pack in the underbelly, and by the thinner winds pushing, making the ice easier-to-move around, Finocchio said.

Stronger really storms exponents of trouble too

With climate change, hurricanes may increase in the spring as well, climate scientist Chelsea Parker said at the meeting. This is a problem because eddies can freeze the sea first in the spring, then melt in the summer.

Parker, of NASA’s Goddard Space Flight Center in Greenbelt, Md., and his colleagues ran computer simulations of spring cyclone behavior in the Arctic under past, present and projected climate conditions. By the end of the century, the maximum near-surface wind speeds of spring cyclones — about 11 kilometers per hour today — could reach 60 km/h, the researchers found. Spring and future cyclones at peak temperatures can keep up to a quarter of their lifetime, up from about 1 percent today. Storms are likely to move further, the team says.

“The reduction of sea ice cover will allow warmer Arctic seas to feed these storms and perhaps allow them to penetrate further into the Arctic,” said Vavrus, who was not involved in the research.

Parker and his team plan to study the future evolution of Arctic cyclones in other seasons to get a bigger picture of how climate change affects weather.

For now, it seems certain that arctic cyclones are not going anywhere. What is less clear is that the fury of men contends with the raging storms.