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Climate: Arctic sea ice third-lowest on record for May

Antarctic sea ice at record high; northern hemisphere snow cover shows rapid spring decline

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Low spring snow cover in the northern hemisphere.

Staff Report

FRISCO — Arctic sea ice extent in May was about a quarter of a million square miles below the 1981-2010 average, ending up as the third-lowest on record for the month, according to the latest update from the National Snow and Ice Data Center.

By contrast, sea ice extent around Antarctica is at a record high, almost half a million square miles above the 1981-2010 baseline, marking the highest May Antarctic sea ice extent on record. Read the full NSIDC report here. Continue reading

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Climate: Arctic sea ice peaks for the year

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Arctic sea ice extent is declining at 2.6 percent each decade.

March surge boosts extent late in the season

Staff Report

FRISCO — Arctic sea ice grew to its maximum extent for the year on March 21, reaching 5.70 million square miles. According to the National Snow and Ice Data Center, it was the fifth-lowest maximum extent in the satellite monitoring era, starting in 1978. The lowest maximum extent occurred in 2011, at 5.65 million square miles.

The average date for maximum sea ice extent is March 9, just a couple of weeks after the spring equinox, but the date varies from year to year. The latest maximum on record was in 2011, when sea ice extent expanded through March 31. Through 2014, the linear rate of decline for March ice extent is 2.6 percent per decade relative to the 1981 to 2010 average. Continue reading

Climate: Clear signs of Arctic sea ice meltdown

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Melt pond on Arctic sea ice. Photo courtesy Polarstern.

Polar ice cap losing ground to global warming

Staff Report

FRISCO — While the Earth still sports an impressive mid-winter polar ice cap, more and more research suggests that global warming is eating away at the ice from the edges and from beneath, as warmer ocean temperatures delay the onset of sea ice formation.

On a geological scale, the pace is astounding. The length of the melt season for Arctic sea ice is growing by several days each decade, and an earlier start to the melt season is allowing the Arctic Ocean to absorb enough additional solar radiation. In some areas that heat is enough to melt as much as four feet of the Arctic ice cap’s thickness, according to a new study by National Snow and Ice Data Center and NASA researchers.

Continue reading

Climate: Slow growth for Arctic sea ice in February

This year’s winter extent likely to be one of the lowest on record

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Arctic sea ice extent this winter has been hovering near a record low. Graphic courtesy NSIDC.

By Summit Voice

FRISCO — With just a few more days to go before Arctic sea ice starts its annual retreat, it looks like this year’s maximum extent will be one the lowest on record. Sea ice extent has been tracking below average nearly all winter and dropped below previous record low levels in early February, staying there ever since.

The extent generally peaks in mid-March before it starts to give way to warmer air temperatures and longer days with more hours of sunlight. This year, temperatures in the Arctic have been distinctly higher than average, resulting in a slower than average expansion of the winter ice cover. Overall, sea ice grew at a rate about 26 percent slower than the 1981 to 2010 average. Continue reading

Global warming: Study shows Arctic sea ice melt season lengthening by five days per decade

Autumn freeze coming 11 days later in some regions

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There’s probably no stopping the decline of Arctic sea ice.

By Summit Voice

FRISCO — Averaged across the Arctic, the melt season is lengthening by five days each decade, with much of the change coming in the fall, when a warmer ocean simply takes longer to freeze than in the past.

“The extent of sea ice in the Arctic has been declining for the last four decades,” said University College London researcher Julienne Stroeve, part of a research team that studied satellite data to track sea ice trends in the age of global warming.

The data confirm that the Arctic Ocean absorbing ever more of the sun’s energy in summer, leading to an ever later appearance of sea ice in the autumn. In some regions, autumn freeze-up is occurring up to 11 days per decade later than it used to. Continue reading

Not cool — Satellite data help pinpoint the effects of dwindling Arctic sea ice

The magnitude of surface darkening is twice as large as that found in previous studies

Earth. Composite satellite image courtesy NASA.

That white ice cap on top of the world is shrinking, and as it does, it will amplify the effects of heat-trapping greenhouse gases. Composite satellite image courtesy NASA’s Blue Marble series.

By Summit Voice

FRISCO — The Arctic ice cap is more than just a home for polar bears. During the summer, the vast expanse of white helps cool the earth — like putting a wet, white bandana on your head during a hot summer summer day.

But as the sea ice extent shrinks each year, the cooling effect is diminished. And climate models may be underestimating the impacts of the loss of Arctic Sea ice, according to new research based on detailed satellite measurements of the Earth’s reflectivity.

As the sea ice melts, its white reflective surface is replaced by a relatively dark ocean surface. This diminishes the amount of sunlight being reflected back to space, causing Earth to absorb an increasing amount of solar energy. Continue reading

Will global warming drive more extreme Arctic storms?

Study links warming climate and Arctic cyclone frequency

A cyclonic storm spins over the center of the Arctic Ocean. Photo courtesy NASA Earth Observatory

A cyclonic storm spins over the center of the Arctic Ocean. Photo courtesy NASA/Goddard/MODIS Rapid Response Team. Visit this NASA website for more information.

By Summit Voice

FRISCO — A changing air pressure regime over the Arctic resulting from warmer temperatures may be driving an increase in extreme storms in the region. The hurricane-like cyclones that traverse the northern waters from Iceland to Alaska may foreshadow even more intense weather ahead, according to Dr. Stephen Vavrus, of the University of Wisconsin-Madison.

“This research shows that the Arctic appears to be expressing symptoms expected from ongoing climate change,” Vavrus said, explaining the findings of the study published in Geophysical Research Letters.

“The long-term decline in atmospheric pressure over most of the Arctic is consistent with the response typically simulated by climate models to greenhouse warming, and this study finds a general corresponding increase in the frequency of extreme Arctic cyclones since the middle 19th century,” he said. Continue reading

Can polar bears adapt to global warming?

A polar bear roams a coastal strand. PHOTO BY SUSANNE MILLER, USFWS.

A polar bear roams a coastal strand. Photo courtesy Susanne Miller, USFWS.

Studies show changing foraging behavior

By Summit Voice

FRISCO — A shared genetic heritage with brown bears may enable some polar bears to adapt as their icy Arctic hunting grounds shrink in the face of global warming.

As Arctic sea ice dwindles, polar bears have a limited amount of time to hunt their historically preferred prey — ringed seal pups — and must spend more time on land.

But polar bears in the western Hudson Bay region are using flexible foraging strategies while on land, such as prey-switching and eating a mixed diet of plants and animals, as they survive in their rapidly changing environment.

“There is little doubt that polar bears are very susceptible as global climate change continues to drastically alter the landscape of the northern polar regions,” said Robert Rockwell, a research associate  at the American Museum of Natural History’s department of ornithology. “But we’re finding that they might be more resilient than is commonly thought.” Continue reading

Arctic sea ice wavers near record low in December

Ice extent shrinking about 18,000 square miles per year

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What’s happening with polar sea ice?

By Summit Voice

FRISCO — December sea ice in the Arctic remained well below average, with the average extent ending up as the fourth-lowest on record — 270,300 square miles below the 1981 to 2010 average — according to the monthly update from the National Snow and Ice Data Center.

Low-ice conditions prevailed in the Barents Sea and along the entire northwest Pacific coast, including the Bering Sea and the Sea of Okhotsk. In the Greenland Sea and Baffin Bay, sea ice extent was near average.

The early part of December was dominated by a positive Arctic Oscillation pattern, but this shifted to near-neutral conditions by the end of the month. The Icelandic low, covering much of the northern North Atlantic Ocean, was stronger than average, and pressures were higher than average over the Bering Sea and Alaska. Continue reading

Climate study links rainy European summers with dwindling Arctic sea ice

A NASA satellite image shows Arctic sea ice.

A NASA satellite image shows Arctic sea ice. Image courtesy NASA.

Changes in the Arctic likely to have widespread hemispheric impacts

By Summit Voice

FRISCO — A new climate study by scientists at the University of Exeter (UK) adds to the growing body of research looking at the hemispheric impacts of dwinding Arctic sea ice.

The findings suggest that that the loss of ice shifts the jet stream farther south, bringing increased summer rainfall to northwestern Europe, but drier conditions to the Mediterranean region. The study could offer an explanation for the extraordinary run of wet summers experienced by Britain and northwest Europe between 2007 and 2012.

In another recent study, scientists with the Cooperative Institute for Research in Environmental Science found that as sea ice disappeared, the areas of relatively warm open water began to strongly influence the atmosphere, increasing surface temperatures in the region, and shifting low- and high-pressure zones around most markedly in the fall and winter.

And a NOAA study found Arctic warming has shifted the normal west-to-east flowing upper-level winds to a more north-south undulating, or wave-like pattern. This new wind pattern transports warmer air into the Arctic and pushes Arctic air farther south, and may influence the likelihood of persistent weather conditions in the mid-latitudes. Continue reading

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