Tag Archives: sea ice

Sea of Slush: Arctic sea ice lows mark a new polar climate regime

By Natalie Thomas and Cassandra Garrison

ARCTIC OCEAN (Reuters) – At the edge of the ice blanketing part of the Arctic Ocean, the ice on Monday looked sickly. Where thick sheets of ice once sat atop the water, now a layer of soft, spongy slush slid and bobbed atop the waves.

From the deck of a research ship under a bright, clear sky, “ice pilot” Paul Ruzycki mused over how quickly the region was changing since he began helping ships spot and navigate between icebergs in 1996.

“Not so long ago, I heard that we had 100 years before the Arctic would be ice free in the summer,” he said. “Then I heard 75 years, 25 years, and just recently I heard 15 years. It’s accelerating.”

As if on cue, scientists on Monday said the vast and ancient ice sheet sitting atop Greenland had sloughed off a 113 square kilometer chunk of ice last month. The section of the Spalte Glacier at the northwest corner of the Arctic island had been cracking for several years before finally breaking free on Aug. 27, clearing the way inland ice loss to the sea, the Geological Survey of Denmark and Greenland reported.

With climate change driving up Arctic temperatures, the once-solid sea ice cover has been shrinking to stark, new lows in recent years. This year’s minimum, still a few days from being declared, is expected to be the second-lowest expanse in four decades of record-keeping. The record low of 3.41 million square kilometers – reached in September 2012 after a late-season cyclonic storm broke up the remaining ice – is not much below what we see today.

“We haven’t gone back at all to anything from 30 to 40 years ago,” said climatologist Julienne Stroeve at the National Snow and Ice Data Center in Boulder, Colorado. And as climate change continues, scientists say the sea ice is unlikely to recover to past levels.

In fact, the long-frozen region is already shifting to an entirely new climate regime, marked by the escalating trends in ice melt, temperature rise and rainfall days, according to new research published Monday in the journal Nature Climate Change.

Those findings, climate scientist Laura Landrum said, were “unnerving.”

All three variables – sea ice, temperatures and rainfall – are now being measured well beyond the range of past observations. That makes the future of the Arctic more of a mystery.

“The new climate can’t be predicted by the previous climate,” Landrum explained. “The year-to-year variability, the change in many of these parameters, is moving outside the bounds of past fluctuations.”

Sea ice coverage minimums, in particular, are now about 31% lower than in the decade after 1979, when satellite observations began. The ice has also lost about two-thirds of its bulk, as much of the thicker ice layer built up over years has long since melted away. The current ice regime actually began about two decades ago, the study found.

This vanishing of sea ice also contributes to the region’s warming, as the icy white expanse is replaced by patches of dark water that absorb solar radiation rather than reflecting it back out of the atmosphere. The process, referred to as Arctic amplification, helps to explain why the Arctic has warmed more than twice as fast as the rest of the world over the last four decades.

The polar north will also likely see more days of rain rather than snow, which would further eat into the ice. For the new research, Landrum and her colleague Marika Holland at the National Center for Atmospheric Research analyzed sea ice, air temperature and precipitation data since 1950 to project climate scenarios up to the end of the century. They used computer simulations in the analysis and assumed the world’s release of greenhouse gas emissions would continue at a high trajectory.

Back in the Arctic Ocean aboard the Greenpeace Ship Arctic Sunrise research ship, biologist Kirsten Thompson of the University of Exeter said the new study was important in underlining “how fast and how profoundly the Arctic is changing.”

For Thompson, that means big change for the region’s wildlife, from polar bears and insects to the whales she focuses on studying. “All their distributions are changing,” Thompson said. “We might find in the Arctic there will be winners and losers,” as new species enter the region and out compete indigenous animals.

“Other species certainly will not be able to survive in the future.”

(Reporting by Natalie Thomas in the Arctic Ocean and Cassandra Garrison in Buenos Aires; Editing by Katy Daigle and Lisa Shumaker)

Alaska’s hottest month portends transformation into ‘unfrozen state’

Smoke shrouds Summit Lake with a thick blanket of smoke from the Swan Lake Fire on Kenai Peninsula, Alaska, U.S., July 5, 2019. REUTERS/Yereth Rosen

By Yereth Rosen

ANCHORAGE, Alaska (Reuters) – July 2019 now stands as Alaska’s hottest month on record, the latest benchmark in a long-term warming trend with ominous repercussions ranging from rapidly vanishing summer sea ice and melting glaciers to raging wildfires and deadly chaos for marine life.

July’s statewide average temperature rose to 58.1 degrees Fahrenheit (14.5 degrees Celsius), a level that for denizens of the Lower 48 states might seem cool enough but is actually 5.4 degrees above normal and nearly a full degree higher than Alaska’s previous record-hot month.

The new high was officially declared by the National Oceanic and Atmospheric Administration (NOAA) in its monthly climate report, released on Wednesday.

More significantly, July was the 12th consecutive month in which average temperatures were above normal nearly every day, said Brian Brettschneider, a scientist with the Alaska Center for Climate Assessment and Policy (ACCAP) at the University of Alaska Fairbanks.

Of Alaska’s 10 warmest months on record, seven have now occurred since 2004.

“You can always have a random kind of warm month, season or even year,” Brettschneider said. “But when it happens year after year after year after year after year, then statistically it fails the test of randomness and it then becomes a trend.”

Alaska, like other parts of the far north, is warming at least twice as fast as the planet as a whole, research shows. And over the past 12 months, Brettschneder said, that warming has crossed a threshold – shifting Alaska from an environment with average temperatures below freezing to above freezing.

It used to be that Alaska was generally a frozen state, he said, adding, “Now we’re an unfrozen state.”

Runoff from accelerated melting of glaciers and high-altitude snowfields sent some rivers to near or above flood stage in early July, despite a drought gripping much of the state, including the world’s largest temperate rain forest in southeastern Alaska.

Sea ice, which has been running at record or near-record lows since spring across the Arctic, completely vanished from waters off Alaska by the start of August. The nearest stretch of ice this summer, said ACCAP climate scientist Rick Thoman, lies about 150 miles (240 km) north of Kaktovik, a village above the Arctic Circle on the northeastern edge of Alaska.

A sign reading "Sorry we are all out of ice" is posted on the door of a gas station in Anchorage, Alaska, U.S., July 7, 2019. REUTERS/Yereth Rosen

A sign reading “Sorry we are all out of ice” is posted on the door of a gas station in Anchorage, Alaska, U.S., July 7, 2019. REUTERS/Yereth Rosen

NO ICE FOR WALRUSES

The effect on Pacific walruses is particularly acute.

Walruses normally perch on floating ice to rest while diving for food and to take care of their newborn calves. Now, with no ice in sight, the walruses have crowded onto the Chukchi Sea shoreline earlier in the year than at any time on record, according to the U.S. Fish and Wildlife Service.

Thousands of walruses – almost all adult females and their young calves – congregated by July 25 on a Chukchi Sea beach near the Inupiat village of Point Lay. Walruses have been coming ashore there almost every year since 2007, then a record-low Arctic ice year, but they have rarely been forced ashore before autumn.

Beach crowding can be dangerous for the large, tusked creatures. If they are spooked by noise or the appearance of a predator, they might stampede into the water, trampling younger and smaller animals to death.

They are not the only marine mammals suffering through the hot Alaska summer.

Thirty-two dead gray whales have been found in Alaska waters this year, six of them in the Bering Strait region or the Chukchi Sea off northwestern Alaska, said Julie Speegle, a NOAA spokeswoman in Juneau. As of mid-July, 137 dead seals had been found on Bering Strait-area beaches, Speegle said.

Seabird carcasses are littering beaches in what has shaped up as the fifth consecutive year of large bird die-offs in Alaska.

High numbers of salmon, apparently overcome by the heat before getting the chance to spawn, have been found floating dead in rivers and streams around western Alaska.

The warming trend has been uncomfortable for humans as well.

Fueled in part by the heat, wildfires across the state have burned more than 2.4 million acres (970,000 hectares) as of early August, spewing smoke and soot that has fouled the air quality of several cities and regions. The smoke pollution poses an unusual quandary for sweltering Alaskans, most of whom live without air conditioning.

“When it’s hot and smoky, Alaska doesn’t have a good way to cope with that,” said Thoman, the ACCP climate scientist whose hometown of Fairbanks was particularly hard hit by wildfire smoke. “Open your windows and you get smoked up. Keep your windows closed and you get hot.”

In Anchorage, where temperatures reached a record daytime high of 90 degrees Fahrenheit (32.2 degrees Celsius) last month, Brettschneider had a similar take.

“I tell people we’re not built for heat. Our houses are built to store heat,” he said.

(Reporting by Yereth Rosen in Anchorage; Editing by Bill Tarrant, Steve Gorman and Cynthia Osterman)

Arctic ice loss driven by natural swings, not just mankind

FILE PHOTO: An undated NASA illustration shows Arctic sea ice at a record low wintertime maximum extent for the second straight year, according to scientists at the NASA-supported National Snow and Ice Data Center (NSIDC) and NASA. NASA/Goddard's Scientific Visualization Studio/C. Starr/Handout via Reuters/File Photo

By Alister Doyle

OSLO (Reuters) – Natural swings in the Arctic climate have caused up to half the precipitous losses of sea ice around the North Pole in recent decades, with the rest driven by man-made global warming, scientists said on Monday.

The study indicates that an ice-free Arctic Ocean, often feared to be just years away, in one of the starkest signs of man-made global warming, could be delayed if nature swings back to a cooler mode.

FILE PHOTO: Eureka Sound on Ellesmere Island in the Canadian Arctic is seen in a NASA Operation IceBridge survey picture taken March 25, 2014.

FILE PHOTO: Eureka Sound on Ellesmere Island in the Canadian Arctic is seen in a NASA Operation IceBridge survey picture taken March 25, 2014. NASA/Michael Studinger/Handout via REUTERS/File Photo

Natural variations in the Arctic climate “may be responsible for about 30–50 percent of the overall decline in September sea ice since 1979,” the U.S.-based team of scientists wrote in the journal Nature Climate Change.

Sea ice has shrunk steadily and hit a record low in September 2012 — late summer in the Arctic — in satellite records dating back to 1979.

The ice is now around the smallest for mid-March, rivaling winter lows set in 2016 and 2015.

The study, separating man-made from natural influences in the Arctic atmospheric circulation, said that a decades-long natural warming of the Arctic climate might be tied to shifts as far away as the tropical Pacific Ocean.

“If this natural mode would stop or reverse in the near future, we would see a slow-down of the recent fast melting trend, or even a recovery of sea ice,” said lead author Qinghua Ding, of the University of California, Santa Barbara.

But in the long term the build-up of man-made greenhouse gases would become an ever more overwhelming factor, he wrote in an e-mail.

“Looking ahead, it is still a matter of when, rather than if, the Arctic will become ice-free in summer,” said Ed Hawkins, of the University of Reading, who was not involved in the study.

FILE PHOTO: The crew of the U.S. Coast Guard Cutter Healy, in the midst of their ICESCAPE mission, retrieves supplies for some mid-mission fixes dropped by parachute from a C-130 in the Arctic Ocean in this July 12, 2011 NASA handout photo obtained by Reuters June 11, 2012. NASA/Kathryn Hansen/Handout via REUTERS/File Photo

FILE PHOTO: The crew of the U.S. Coast Guard Cutter Healy, in the midst of their ICESCAPE mission, retrieves supplies for some mid-mission fixes dropped by parachute from a C-130 in the Arctic Ocean in this July 12, 2011 NASA handout photo obtained by Reuters June 11, 2012. NASA/Kathryn Hansen/Handout via REUTERS/File Photo

The melt of the Arctic is disrupting the livelihoods of indigenous peoples and damaging wildlife such as polar bears and seals while opening the region to more oil and gas and shipping.

Professor Andrew Shepherd, of Leeds University, who did not participate in the study, welcomed it as pinning down the relative shares of natural and man-made influences. “Nobody’s done this attribution before,” he said.

The findings could help narrow down huge uncertainties about when the ice will vanish.

In 2013, a U.N. panel of climate scientists merely said human influences had “very likely contributed” to the loss of Arctic ice, without estimating how much. It said that the ice could disappear by mid-century if emissions keep rising.

(Reporting By Alister Doyle; Editing by Catherine Evans)