Global Warming

Arctic ice reaches lowest recorded extent

The extent of Arctic sea ice, with reached its 2018 lowest extent on 23 September and again on 23 September, has tied with 2008 and 2010 for the sixth lowest summertime minimum extent in the satellite record.

This is the conclusion from satellite data by NASA and the NASA-supported National Snow and Ice Data Centre (NSIDC) at the University of Colorado Boulder, which showed that, at 1,77-million square miles (4,59-million square kilometres), 2018 effectively tied with.

Arctic sea ice, the cap of frozen seawater blanketing most of the Arctic Ocean and neighbouring seas in wintertime, follows seasonal patterns of growth and decay. It thickens and spreads during the fall and winter and thins and shrinks during the spring and summer.

But in the past decades, increasing temperatures have led to prominent decreases in the Arctic sea ice extents, with particularly rapid decreases in the minimum summertime extent.

The shrinking of the Arctic sea ice cover can ultimately affect the planet’s weather patterns and the circulation of the oceans.

Nasa arctic ice

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Global Warming

Sea Ice Hits Record Lows at Both Poles

    

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Arctic temperatures have finally started to cool off after yet another winter heat wave stunted sea ice growth over the weekend. The repeated bouts of warm weather this season have stunned even seasoned polar researchers, and could push the Arctic to a record low winter peak for the third year in a row.

Meanwhile, Antarctic sea ice set an all-time record low on Monday in a dramatic reversal from the record highs of recent years.

Sea ice at both poles has been expected to decline as the planet heats up from the buildup of greenhouse gases in the atmosphere. That trend is clear in the Arctic, where summer sea ice now covers half the area it did in the early 1970s. Sea ice levels in Antarctica are much more variable, though, and scientists are still unraveling the processes that affect it from year to year.

The large decline in Arctic sea ice allows the polar ocean to absorb more of the sun’s incoming rays, exacerbating warming in the region. The loss of sea ice also means more of the Arctic coast is battered by storm waves, increasing erosion and driving some native communities to move. The opening of the Arctic has also led to more shipping and commercial activity in an already fragile region.

Sea ice area isn’t the only way to measure the health of Arctic sea ice; the thickness of the sea ice has also suffered during the repeated incursions of warmth.

Antarctic sea ice is an altogether different beast. Instead of an ice-filled ocean surrounded by land, it is a continent surrounded by ocean that sees much more variability in sea ice levels from year to year for reasons that aren’t fully understood.

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For several of the past few years, the sea ice that fringed Antarctic reached record highs. That growth of sea ice could have potentially been caused by the influx of freshwater as glaciers on land melted, or from changes in the winds that whip around the continent (changes that could be linked to warming or the loss of ozone high in the atmosphere).

But this year, a big spring meltdown in October and November suddenly reversed that trend and has led to continued record low sea ice levels as the summer melt season progressed. On Monday, Antarctic sea ice dropped to an all-time record low, beating out 1997.

Sea ice has been particularly low in the Amundsen Sea region of Western Antarctica, thanks to unusually high temperatures there. But it’s not clear what is ultimately driving this dramatic reversal in Antarctic sea ice, or whether it will be temporary or marks a longer-term shift.

Humans accelerating global warming by 170 times: study

Humans are driving the warming of the Earth 170 times faster than natural forces, according to a new mathematical formula.

Scientists in Australia and Sweden have developed the equation, which assesses the impact of human activity on the climate and compares it to events such as volcanic eruptions and changes to the planet’s orbit.

Professor Will Steffen, a climate scientist from the Australian National University (ANU), said no natural events came close to the impact humans have made.

“Over the last century or so, we can see that the impact of humans – through fossil fuels, through forest clearing, through all sorts of changes to the biosphere – have become more important than these other forces,” he said.

Professor Steffen, who is also on the Climate Council, and his fellow researchers have labelled the formula the Anthropocene Equation.

Officially, the Earth is in the Holocene period, but scientists such as Professor Steffen are pushing for the modern era to be reclassified to reflect the massive impact humans have had. The scientists behind the formula found the biggest change in the climate has come since 1970.

“Since 1970, temperature has been rising at a rate of about 1.7 degrees per century,” Professor Steffen said.

“When you compare those two, since the 1970s, the climate has been changing at a rate 170 times faster than that long-term background rate.”

Global Warming

Captain Cook’s detailed 1778 records confirm global warming today in the Arctic

in the summer of 1778, when Capt. James Cook tried to find a Western entrance to the route, his men toiled on frost-slicked decks and complained about having to supplement dwindling rations with walrus meat.

The British expedition was halted north of the Bering Strait by “ice which was as compact as a wall and seemed to be 10 or 12 feet high at least,” according to the captain’s journal. Cook’s ships followed the ice edge all the way to Siberia in their futile search for an opening, sometimes guided through fog by the braying of the unpalatable creatures the crew called Sea Horses.

More than two centuries later, scientists are mining meticulous records kept by Cook and his crew for a new perspective on the warming that has opened the Arctic in a way the 18th century explorer could never have imagined. The results, published this month in the journal Polar Geography, confirm the significant shrinkage of the summer ice cap and shed new light on the timing of the transformation.

From the time of Cook until the 1990s, you more or less could count on hitting the ice somewhere around 70 degrees north in August. Now the ice edge is hundreds of miles farther north.

That meshes with modern observations that confirm rapid shrinkage of the Arctic ice pack over the past three decades, Overland said. The total volume of ice in summer is now 60 to 70 percent lower than it was in the 1980s, while Arctic temperatures have increased at twice the rate of the rest of the planet as a result of rising greenhouse-gas levels.

With more melting in the summer and delayed freezing in the fall, the once-elusive Northwest Passage is now navigable for private yachts and commercial vessels.

Global Warming

Disappearing Arctic Ice

The relentless retreat of the Arctic’s summertime sea ice accelerated this summer, reaching an all-time record low coverage for June at the end of last month. Arctic sea ice coverage dropped to a June record low of 4.09 million square miles.

The U.S. National Snow and Ice Data Centre says the polar sea ice extent in June was 100,000 square miles smaller than in 2010, when the previous record low coverage was set for June.

The remaining ice was measured at 525,000 square miles below the 1981-2010 long-term average.

March was the only month so far this year that a new record low for Arctic sea ice coverage wasn’t set.

After a winter of record warmth, ice is currently melting 70 percent faster than the summer average.

Global Warming

Arctic sea ice hits record low

Arctic sea ice has reached its lowest winter point since satellite observations began in the late 1970s, raising concerns about faster ice melt and rising seas due to global warming, US officials have said.

The maximum extent of sea ice observed was 5.6 million square miles (14.5 million square kilometres) on February 25, earlier than scientists had expected, said the report by the National Snow and Ice Data Centre yesterday.

Below-average ice conditions were observed everywhere except in the Labrador Sea and Davis Strait. The sea ice was about 425,000 square miles below the average from 1981 to 2010, a loss equal to more than twice the size of Sweden. It was also 50,200 square miles below the previous lowest maximum that occurred in 2011.

Environmentalists said the report offered more evidence of worsening global warming, and urged action to curb the burning of fossil fuels that send greenhouse gases into the atmosphere.

Global Warming

Arctic Sea Ice Plunges To Record Low Extent For Late Winter

Instead of easing toward its typical March maximum in coverage, the Arctic’s sea ice appears to be more inclined toward getting a head start on its yearly summer melt-out. As of Sunday, March 8, Arctic sea ice as calculated by Japan’s National Institute of Polar Research extended across 13.65 million square kilometres. This value is more than 450,000 sq km – roughly the size of California – below the record extent for the date.

Even more striking is the consistency of the ice loss over the last couple of weeks. March is often a time of rapid gains and losses in ice cover, as seasonal warming and melting battle it out with quick refreezing when shots of cold air return. This year, the ice extent peaked on February 15 at 13.94 million sq km, and it looks increasingly unlikely that the ice will manage to return to that very early peak over the next couple of weeks.

No season in the Japanese database has fallen short of the 14-million mark, so if the February peak stands, it will mark the lowest maximum in the Arctic since satellite monitoring began in 1979. Not only is Arctic sea ice essential to many ecosystems: it serves as a powerful tracer of recent warming, and its absence in summer allows open water to absorb much more heat from sunlight. While the ice has seen some modest recovery in recent years, it has failed to fully mend the fabric torn by the record-setting drop of 2007. The overall thickness of the ice, and the fraction that’s survived for multiple years (multiyear ice), have both suffered major losses.

Global Warming

Arctic Is Heating Up Twice as Quickly as Rest of World

Bad news for polar bears: The Arctic is still warming at twice the pace of the rest of the planet, according to a new federal report.

Last year, air temperatures in the northernmost regions of the globe were, on average, 1.8 degrees Fahrenheit (1 degree Celsius) higher than normal. Unusually warm years like 2014 have only become more frequent in the Arctic in the past decade, even as the rate of temperature increase slowed for the rest of the world.

In 2014, the Greenland Ice Sheet’s heat-deflecting brightness hit a low; spring snow cover dwindled to record lows in Eurasia; polar regions had a below-average extent of summer sea ice, and as for the polar bears that depend on that ice to survive, some populations have declined, according to the report.

The findings are included in the National Oceanic and Atmospheric Association’s (NOAA) annual “Arctic Report Card,” a comprehensive review of the North Pole’s health that is assembled by more than 60 scientists.

The Arctic warms at a higher rate than lower latitudes because of a well-documented effect known as Arctic amplification of global warming, Richter-Menge told reporters. Arctic amplification is a self-feeding cycle. Because of their light colour, sea ice and snow bounces radiation from the sun back into the atmosphere. But when more ice and snow melts, more of the dark-coloured patches of earth and ocean are exposed, locking more heat into the already-warming planet’s surface.

Rising temperatures in the Arctic are thought to affect the rest of the planet. Some research has suggested that warming around the North Pole can cause the typical path of the jet stream to go haywire, though scientists have yet to reach a consensus. Without data for a long period of time, it’s difficult to tell whether this phenomenon is really a trend or part of the “normal chaos” of the atmosphere, said James Overland, an oceanographer with NOAA’s Pacific Marine Environmental Laboratory. Regardless of the cause, a wavy jet stream can have a huge influence on weather, the report illustrates. For example, a twisted jet stream led to remarkable temperature spikes in Alaska in January, when the region experienced temperatures as much as 18 degrees F (10 degrees C) higher than normal.

Environment

Polar Vortex Outbreaks Linked to Vanishing Arctic Ice

Vanishing Arctic sea ice appears to have been responsible for the spells of bitterly cold wintertime conditions in the Northern Hemisphere during recent years.

Masato Mori of the University of Tokyo and colleagues found colder-than-normal winters are now twice as likely to occur across Eurasia under these conditions than before the record polar melting began.

This past September saw the sixth-lowest minimum Arctic sea ice extent ever observed.

A warming Arctic causes the polar jet stream to be weaker, allowing frigid weather systems to creep farther south.

It can also promote blocking weather patterns that cause the chill to linger for weeks.

While the study focused on a part of Eurasia that stretches from Eastern Europe to China, the past few winters have also brought frigid conditions not seen in decades to parts of Western Europe and North America.

But Adam Scaife of the U.K. Met Office says the polar blasts are likely to end once all of the ice disappears in the Arctic during autumn. Some models predict it could happen during the 2030s.

“The key thing here is that they argue that climate change wins in the long run,” Scaife told New Scientist. This means that while our current winters may at times be bitterly cold, global warming will eventually catch up once the Arctic refrigerator defrosts.

Global Warming

Arctic Ice Retreat Creates Giant Swells For The First Time

The Beaufort Sea in Arctic Ocean is usually frozen. The water is covered with ice most of the time. But researchers have recorded giant waves, as high as 16 feet, just north of Alaska. Swells of that size have stunned the scientists because they have the potential to break up Arctic ice much faster than expected. The North is changing, and it’s changing fast as the sea ice retreats due to global warming.

Jim Thomson of the University of Washington recorded the wave measurements with the help of sensors. The house-size waves were measured during a September 2012 storm. Thomson told The Washington Post that 16 feet swells were the average. The biggest single wave was about 29 feet.

Until recently, the Arctic Ocean remained ice-covered throughout the summer, so there were no waves to measure. But the area of open water is increasing. Thomson said the Arctic ice never retreated more than 100 miles during summer in the past. But in 2012, it retreated well over 1,000 miles. The expanded ice retreat leaves much of the Beaufort Sea ice-free by the end of summer.

Arctic ocean

Another Massive Hole Appears in Siberia

It’s uncertain yet what’s caused the sinkholes, but experts said global warming may play a part, when permafrost melts, gas is released, causing an underground explosion.

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Global Warming

Arctic Winter Sea Ice Still in Decline: Fifth-Lowest Ever

The winter ice cap around the North Pole reached its greatest extent on March 21, but it also fell to the fifth-lowest peak coverage on record.

Arctic sea ice usually grows to the largest expanse for winter on or about March 9.

The U.S. National Snow and Ice Data Center said the annual peak would have occurred about then and been even smaller than the eventual coverage of 5.76 million square miles had it not been for strong and frigid surface winds that swirled around the Arctic in mid-March.

The Colorado-based center said the latest measurements reinforce previous studies that have revealed ice around the North Pole is disappearing much faster than earlier predictions.

The ice has steadily declined by an average of 12 percent per decade since 1978.

Experts predict the Arctic will lose all of its summer ice within decades, if not sooner.

This winter’s maximum coverage of Arctic sea ice was much lower than the average for the past 30 years.

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