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The Arctic was missing an ice patch the size of Texas and California this winter

SeaIceBoat-1By Andrew Freedman From Mashable?

The Arctic climate sent yet another in a long series of alarm bells on Thursday as scientists announced that the sea ice cover in the region hit a record low maximum for the year. The winter maximum typically occurs in March, but this year it took place about two weeks earlier than average, with sea ice most likely maxing out on Feb. 25.

The official call was made Thursday by the National Snow and Ice Data Center (NSIDC) in Boulder, Colorado, which tracks ice conditions at the poles. The record low maximum marks another step in the transformation of the Arctic from an inaccessible area for shipping and oil and gas drilling into what may become a seasonally ice-free region.

The NSIDC cautions that sea ice conditions can vary considerably at this time of year, particularly sea ice extent, which is a measure of the geographical expanse of the ice cover. The consequences of this transition will reverberate far beyond the Arctic, in the form of changing weather patterns, an altered geopolitical landscape and potentially dire fate of iconic species.

On Feb. 25, the sea ice extent was 5.61 million square miles. This was the lowest in the satellite record, with below average conditions covering the entire Arctic, including open ocean and territorial waters of seven nations. Two exceptions to this were the Labrador Sea and Davis Strait, where sea ice extent was higher.

The maximum extent is 425,000 square miles below the 1981 to 2010 average of 6.04 million square miles, and about 50,000 square miles lower than the previous record low maximum, which occurred in 2011. That’s the equivalent of losing an extra patch of ice the size of Texas and California combined. That’s the equivalent of losing an extra patch of ice the size of Texas and California combined.

The NSIDC waited until mid-March to declare the ice maximum because the downward trend in ice extent after Feb. 25 flattened out for a time, due in part to ice growth in the Bering Sea near Alaska, which helped balance ice losses in the Barents and Kara Seas off the north coasts of Scandinavia and Russia. “Over the next two to three weeks, periods of increase are still possible,” the NSIDC posted on its website. “However, it now appears unlikely that there could be sufficient growth to surpass the extent reached on February 25.”

While the sea ice cover in the Far North has been on a rapid decline since the late 1970s — a trend tied in large part to manmade global warming — there is considerable year-to-year variability due to short-term weather patterns. The winter of 2014-15 featured a persistent and unusually shaped jet stream, which allowed mild air to sneak into the Arctic from the Pacific Ocean, depressing ice cover in the Bering Sea and the Sea of Okhotsk.

In recent weeks, a pattern of atmospheric pressure over the North Atlantic, known as the Arctic Oscillation, has been in a phase that has led to strong southerly winds across the Barents and Kara Seas in particular. In some areas, including the region between Svalbard, Norway and Franz Josef Land, which lies in the Russian Arctic, air temperatures were up to 18 degrees Fahrenheit above average for this time of year.

Sea Ice Mid-March
Arctic sea ice extent through mid-March, showing the peak in February followed by general decline since.
IMAGE: NSIDC
The paltry sea ice peak does not necessarily mean that 2015 will set a new record low summer ice extent according to Julienne Stroeve, a scientist at the NSIDC.

In an interview earlier this month, Stroeve told Mashable that ice thickness is a better predictor of summer ice melt, rather than the winter extent. Thick ice is harder to melt in a single warm season than thin ice cover. The NSIDC will release more information on thickness trends this winter later this spring.

A new study published in the journal Cryosphere found that Arctic sea ice has thinned out more significantly than previously reported, suggesting that the odds favor more record low summer melt seasons. The study, published in early March, found a 65% decline in sea ice thickness across the central Arctic Ocean between 1975 and 2012.

“That’s a more important factor than the total extent,” Stroeve said.

Global warming has set off a positive feedback loop in the Arctic by melting sea ice via milder air and water temperatures, which exposes darker ocean waters to solar radiation, thereby allowing it to absorb more heat and then melt more sea ice. This cycle, known as “Arctic amplification,” helped sea ice dip to a record low in 2012, with slightly higher ice extents observed since then.

While projections vary on when this will occur, most Arctic ice researchers say ice-free summers are likely within the next few decades as the climate continues to warm. This would have sweeping impacts on the longtime inhabitants of this area, as well as iconic species from seals to narwhals and polar bears.

On average, Arctic sea ice extent has declined by 4.52% per decade On average, Arctic sea ice extent has declined by 4.52% per decade, according to the NSIDC. The summer minimum has declined faster than winter levels have, at nearly 14% per decade.

The sea ice decline is opening up portions of the Arctic to shipping and oil and gas drilling. In April, the U.S. will assume a two-year chairmanship of the Arctic Council, a non-binding organization that helps bring together Arctic nations and indigenous peoples to address issues of common concern.

The State Department has indicated that the impacts of global warming, such as sea ice loss, will be a top agenda item under American leadership.

IMAGE: Seaiceboat An ice-breaker carrying tourists plows through drift ice on the Sea of Okhotsk northeast of Japan’s northernmost major island of Hokkaido on Feb. 26, 2015. IMAGE: KYODO/ASSOCIATED PRESS

For more on this story go to: http://mashable.com/2015/03/19/arctic-sea-ice-lowest-winter-maximum/?utm_campaign=Feed%3A+Mashable+%28Mashable%29&utm_cid=Mash-Prod-RSS-Feedburner-All-Partial&utm_medium=feed&utm_source=feedburner&utm_content=Google+Feedfetcher

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