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A “crazy year” in the Arctic has resulted in the second-lowest extent of sea ice in the region, scientists said Monday.
Researchers from the National Snow and Ice Data Center said the minimum was likely reached on September 15, with 1.44 million square miles of ocean covered in ice. Since then, with the drop in temperatures and the formation of new ice, the coverage has been increasing.
Since satellite measurements of sea ice began four decades ago, only 2012 has had a lower minimum, when 1.32 million square miles were measured. The 2020 low was nearly a million square miles less than the average annual low between 1981 and 2010.
An alarming streak continues this year as well: the lowest 14 years of ice have occurred in the past 14 years. Many scientists hope that the Arctic may be ice-free in summers long before the middle of the century.
“It’s been a crazy year in the north, with sea ice at a near-record low, 100-degree heat waves in Siberia and massive wildfires,” said Mark Serreze, director of the National Snow and Ice Data Center, in a statement. “We are heading towards a seasonally ice-free Arctic Ocean, and this year is another nail in the coffin.”
Arctic sea ice grows to its greatest extent during the fall and winter and then melts during the spring and summer. This year’s peak, 5.9 million square miles, was reached in early March.
The researchers noted that, as is the case every year, their announcement of a low was preliminary: a brief spell of heat or changing winds could lead to more thaw. That has happened twice in this century.
Temperatures soared across much of the Arctic this summer. At the end of June, Siberia was engulfed by an area of stagnant air that continued to warm. This led to record temperatures: Verkhoyansk, Russia, 400 miles further north than Anchorage, Alaska, reached 100 degrees Fahrenheit one day.
Sea ice has shrunk by more than 13 percent per decade, relative to the 1981-2010 average, as global warming affects the Arctic more than any other part of the world. The region is heating up more than twice as fast as any other.
The loss of sea ice influences this rapid warming. The ice reflects most of the sunlight that hits it. But when it melts, more ocean is exposed. The surface of the ocean is darker and absorbs more of the sun’s rays, re-emitting the energy as heat. That leads to more warming and more ice loss, and the process continues in what scientists call a feedback loop.
