Antarctica and the Arctic
21 Aug 2014:
Antarctica and Greenland
Losing Ice at Fastest Rate Ever Recorded
Ice sheets in Greenland and Antarctica are losing mass at an unprecedented rate of 500 cubic kilometers per
year — enough ice to cover the Chicago metropolitan area with a layer of ice 600 meters thick — according to
German researchers. Using data from the European Space Agency's CryoSat 2 satellite from 2011 to 2014, the team created the most detailed maps to date of ice elevations across Antarctica and Greenland, accurate to a few meters in height. The results reveal that Greenland alone is losing ice volume by about 375 cubic kilometers per year, doubling since 2009, the scientists report. Ice loss in the West Antarctic Ice Sheet has increased by a factor of three over the same period. Combined, the two ice sheets are thinning at the highest rate observed since altimetry satellite records began about 20 years ago, the study found. Data show that East Antarctica is gaining ice volume, but at a moderate rate that doesn’t compensate the losses on the continent's other side.
30 Jun 2014:
Antarctica's Emperor Penguins
To Be in Serious Decline By 2100, Study Says
Antarctica's Emperor penguins are facing dramatic declines by the end of the century and should be given endangered species status because of the threats posed
Sea ice loss threatens Emperor penguins.
by climate change, according to
an international group of scientists. If sea ice declines at the rates projected by current climate models, at least two-thirds of the colonies will likely shrink by more than 50 percent by 2100, the researchers report in Nature Climate Change
. That conclusion follows a 50-year study in eastern Antarctica of Emperor penguins, an iconic Antarctic species with 45 known colonies. Emperor penguins' survival is highly dependent on sea ice concentrations because they breed on the ice, and too little sea ice reduces the habitat for krill, a critical food source for the penguins. Granting the species protected status under the U.S. Endangered Species Act will provide tools for improving fishing practices of U.S. vessels in the Southern Ocean and potentially for reducing CO2 emissions in the U.S. under the Clear Air Act, the researchers say.
16 Jun 2014:
Skyscraper-Size Ice Structures
Discovered at Base of Greenland Ice Sheet
Melting and refreezing at the base of the Greenland ice sheet has created massive, complex structures the height of skyscrapers and the width of Manhattan, according to
research published in Nature Geoscience
The hidden formations more than a mile below the surface stand in stark contrast to the nearly flat, smooth exterior of the ice sheet and may accelerate its flow toward the sea, researchers say. Scientists had previously interpreted the irregular topography at the base of the ice as hills or mountains, but ice-penetrating radar revealed that the structures were made of ice rather than rock. Scientists from Columbia University explained that as meltwater at the bottom refreezes over hundreds or thousands of years, it radiates heat into the surrounding ice sheet, making it pick up its pace as the ice becomes softer and flows more easily. Greenland's glaciers appear to be moving more rapidly toward the sea as climate warms, but it's unclear how the refreezing process will influence this trend, researchers said.
20 May 2014:
Widespread Greenland Melting
Due to Forest Fires and Warming, Study Says
Rising temperatures and ash from Northern Hemisphere forest fires combined to cause large-scale surface melting of the Greenland ice sheet in 2012, an
echo of a similar event that occurred in 1889, a new study
finds. The massive Greenland ice sheet — the second largest ice body in the world after the Antarctic ice sheet — experiences annual melting at low elevations near the coastline, but surface melt is rare in the dry snow region in its center. In July 2012, however, satellites observed for the first time surface melt across more than 97 percent of the ice sheet, generating reports that the event was almost exclusively the result of climate change. In the new report, published in the journal Proceedings of the National Academy of Sciences
, researchers found that in both 2012 and 1889 exceptionally warm temperatures combined with black carbon sediments from Northern Hemisphere forest fires to darken the surface of the ice sheet to a critical albedo threshold, causing the large-scale melting events. Since Arctic temperatures and the frequency of forest fires are both expected to rise with climate change, large-scale melt events on the Greenland ice sheet may begin to occur almost annually by 2100, the researchers say.
Interview: Can Marine Life Adapt
To the World’s Acidifying Oceans?
As the world’s oceans grow more acidic from increased absorption of atmospheric carbon dioxide, marine scientists are confronting a key question: How well can
organisms like mollusks, crustaceans, and corals adapt to these more corrosive conditions? One of the leading authorities in this field is University of California, Santa Barbara marine biologist Gretchen Hofmann. Her work in recent years has shown, in fact, that some sea organisms that build shells do seem to have some ability to acclimate to more acidic waters. But in an interview with Yale Environment 360
, Hofmann cautions that this adaptive capacity has its limits. The continuing burning of fossil fuels, she says, could push ocean acidity past a tipping point, rendering some mollusks and other organisms unable to build shells.
Read the interview.
08 May 2014:
Natural Variations May Account
For Up to Half of Greenland's Warming
Up to half of the recent climate change in Greenland and surrounding regions — which have warmed at roughly twice the pace of the rest of the planet since 1979 — may be due to natural climate variations that originate in the tropical Pacific and are not connected
Meltwater from Russell Glacier
with the overall warming of the Earth, a new study
says. Still, at least half the warming remains attributable to rising global carbon dioxide emissions, according to research published in the journal Nature
. Climate data and advanced computer models show that changes in the western tropical Pacific Ocean, which has been about 0.3 degrees warmer than normal, have caused shifts in atmospheric pressure over the North Atlantic. Those changes set off a stationary wave in the atmosphere that arcs in a great circle from the tropical Pacific toward Greenland, pulling warmer air over that massive island. "Along this wave train there are warm spots where the air has been pushed down, and cold spots where the air has been pulled up," one author explained. "And Greenland is in one of the warm spots."
Carries on in Key Arctic Ecosystem
At a time of rapidly deteriorating relations between Russia and America, U.S. scientist Joel Berger continues his work with his Russian counterparts
Third in a series of blog posts from the Russian Arctic
on Siberia's Wrangel Island. In the third of three blog posts for Yale Environment 360
, Berger — a biologist with the Wildlife Conservation Society and the University of Montana — writes about efforts to better understand how rapid climate change might affect muskoxen and other wildlife in the Russian and North American Arctic. As Berger explains, a key focus of Russian-American scientific cooperation is Beringia, the region of northwestern Alaska and extreme northeastern Russia where two countries — and continents — are divided by the Bering Sea.
29 Apr 2014:
Exxon Mobil Arctic Project
Possibly At Risk Over Russia Sanctions
Exxon Mobil's development of a Russian Arctic oil project valued at nearly $900 billion is at risk following recent U.S. sanctions on Russian officials as a result of Ukraine's ongoing political crisis, Bloomberg News reports
. Exxon Mobil has partnered with the Russian state-controlled oil company OAO Rosneft to drill an oil-rich geological structure known as Universitetskaya, which contains an estimated 9 billion barrels of oil, valued at $900 billion at current market prices. Rosneft's CEO, Igor Sechin, a longtime member of Russian President Vladimir Putin's inner circle, was sanctioned by the U.S. yesterday, exposing the partnership with Exxon Mobil to additional scrutiny. Exxon Mobil and Rosneft are set to invest an estimated $600 million in drilling at the site in the Kara Sea, which would make the project Exxon's most expensive to-date. A U.S. Treasury official said yesterday that U.S. companies can still do business with Rosneft, but some analysts say Russian companies could become wary of working with Western corporations in the future. Exxon said last week that the project is on schedule.
Studying a Polar Menagerie
On an Island in Arctic Russia
Ninety miles from the Russian mainland and 300 miles above the Arctic Circle, Wrangel Island is home to an eclectic assortment of fauna and flora — muskoxen,
Second in a series of blog posts from the Russian Arctic
polar bears, wolves, reindeer, wolverines, walruses, Asia’s only population of snow geese, and 417 plant species. Joel Berger, a field biologist with the Wildlife Conservation Society and the University of Montana, spent several weeks on Wrangel Island this spring. In the second of three blog posts for e360
, he describes the arduous conditions under which Russian and U.S. scientists collect data on the island’s odd assortment of creatures.
On Far-Flung Wrangel Island,
A Scientist Sizes up Muskoxen
As a field biologist for the University of Montana and the Wildlife Conservation Society, Joel Berger has been to his share of end-of-the-earth places. But few have
Muskoxen on Wrangel Island
rivaled Wrangel Island, the rugged, frozen outpost located 300 miles above the Arctic Circle in Russia’s extreme Far East. In the first of three reports for Yale e360
, Berger describes the arduous trip to Wrangel and the scientific work that has taken him there — research with Russian colleagues on the island’s 900 muskoxen, a shaggy beast that is a relic from the Pleistocene era. In subsequent reports, Berger will describe the motley assortment of wildlife that has colonized Wrangel and the contrasting impacts of climate change on eastern Siberia and Arctic Alaska.
07 Apr 2014:
Newfound Atmospheric 'Hole'
Threatens Polar Ozone Layer, Scientists Say
Researchers have discovered
a large opening in the Earth's atmosphere that is enabling pollutants to rise
Pacific atmosphere hole an elevator to the stratosphere
into the stratosphere and destroy ozone. The hole, which is in a part of the lower atmosphere called the "OH shield," is several thousand kilometers long and is centered over the tropical west Pacific Ocean. It's relatively close to Southeast Asia, a region with a booming population and rapidly increasing air pollution. The hole is a major concern because the OH shield usually scrubs air of chemical compounds emitted near the ground before they can reach the stratosphere, where those compounds can persist for long periods of time, reacting with and destroying ozone, say researchers at Germany's Alfred Wegener Institute who identified the hole. The newly discovered phenomenon acts as a sort of elevator, researchers say, drawing chlorofluorocarbons, sulfur dioxide, and other contaminants straight up to the stratosphere and bypassing the OH shield scrub.
28 Mar 2014:
West Antarctic Glacial Loss
Is Rapidly Intensifying, New Study Shows
Six massive glaciers in West Antarctica are dumping far more ice into the Southern Ocean than they were 40
An 18-mile crack in the Pine Island Glacier
years ago and now account for 10 percent of the world’s sea level rise
, according to a new study. Reporting in Geophysical Research Letters
, an international team of scientists said that the amount of ice draining from the six glaciers has increased by 77 percent since 1973. The scientists said that the ice loss from the six glaciers is so substantial that it equals the amount of ice draining annually from the entire Greenland Ice Sheet. The scientists used satellite data from 1973 and 2013 to gauge the ice loss from the six glaciers. The Pine Island Glacier
is moving more rapidly to the sea than any of the other six, with its speed increasing from 1.5 miles per year in 1973 to 2.5 miles per year in 2013. The glaciers are dumping more ice into the sea primarily because warmer ocean waters are loosening the ice sheets’ hold on the sea floor, which speeds up glacial flow.
06 Mar 2014:
Warm River Water Plays Major
Role in Arctic Sea Ice Melt, Study Finds
Relatively warm water flowing into the Arctic Ocean from rivers contributes significantly to Arctic sea ice melt each summer, a phenomenon that will intensify as the region warms, according to NASA researchers
. The river discharge not only melts coastal sea ice, it also has
a wider climate impact as it creates more open water, which is darker than ice and absorbs more heat from sunlight. As these NASA images show, when water from Canada's Mackenzie River flowed into the Beaufort Sea in the summer of 2012, average surface temperature of the open water rose by 6.5 degrees C (11.7 degrees F) after the pulse of river water. Flow from the Mackenzie raised sea surface temperatures as far as 350 kilometers (217 miles) from the coast. The researchers note that river discharge is becoming an increasingly important contributor to melting Arctic sea ice because the volume and temperature of fresh water discharge is increasing as inland Arctic areas warm more each summer.
19 Feb 2014:
Loss of Arctic Sea Ice
Has Greater Warming Impact Than Expected
The steady disappearance of Arctic sea ice, which is causing the exposed and darker surface of the Arctic Ocean to absorb more sunlight, is having a more profound impact on global warming
estimated, according to a new study. The decline of albedo, or reflectivity, from the Arctic Ocean equals roughly 25 percent of the warming caused by rising carbon dioxide levels, according to scientists at the University of California, San Diego. The impact of this "albedo feedback," in which the highly reflective white surface of sea ice is replaced by heat-absorbing open ocean, is considerably stronger than climate models had predicted, according to the UCSD research
, published in the Proceedings of the National Academy of Sciences.
Researchers had thought increasing Arctic cloud cover might slow the albedo feedback, but this study indicates that is not happening.
04 Feb 2014:
NASA Image of Alaska
Depicts Spring-like Temperatures and Thaw
As the continental U.S. faced frigid weather and major winter storms in January, Alaska experienced record high temperatures.
A map based on NASA satellite data
shows that the last half of January was one of the warmest winter periods in Alaska’s history, with temperatures as much as 40 degrees F (22 C) above normal on some days in the central and western portions of the state. A high pressure system off the state's western coast sent warm air and rain through Alaska instead of down into California, which is in the midst of a record drought. The warmest January temperature ever observed in Alaska was tied on January 27, when the thermometer hit 62 F (16.7 C) at Port Alsworth, in southern Alaska. Combined with rainstorms, the heatwave set off a host of spring-like effects, including avalanches and swollen rivers, which carried major sediment loads into the Gulf of Alaska. Inland, Arctic lakes are also seeing consequences of Alaska's long-term warming trend. A new study
found that lakes in the region froze almost six days later and broke up about 18 days earlier in the winter of 2011 compared to the winter of 1950.
Interview: Activist Kumi Naidoo
On Russia and the Climate Struggle
Kumi Naidoo, the international executive director of Greenpeace, is intimately familiar with the Prirazlomnaya drilling platform in the Russian Arctic. In 2012, he and five other Greenpeace activists were hosed down with frigid water and pelted with pieces of metal as they attempted to climb aboard the platform.
Greenpeace and Prirazlomnaya were back in the news recently when 28 Greenpeace members were arrested and held for several months for storming the rig before being released in December. In an interview with Yale Environment 360
, Naidoo talks about what’s needed to get global climate talks off the ground and launch a green energy revolution, and the reason his activist organization has decided to take such a strong stand against oil drilling in the rapidly melting Arctic Ocean. "We went back [to Prirazlomnaya]," says Naidoo, "because we’re trying to draw a line in the ice, because once this starts it will have breached another threshold of meeting our rapacious appetite for oil and gas in the most fragile of environments." Read the interview.
13 Jan 2014:
Pine Island Glacier Has
Melted Beyond Tipping Point, Study Says
A major Antarctic ice mass, the Pine Island Glacier, is melting irreversibly and could add as much as a centimeter to global sea level rise over the next 20 years alone, according to new research published in Nature Climate Change
. Calculations show that the Pine Island Glacier's "grounding line" — where land-based ice meets a floating ice shelf that is an extension of the
glacier — has retreated roughly 10 kilometers in the past decade. Scientists say that the grounding line is in the process of a 40-kilometer retreat that could push it beyond an important tipping point. Pine Island Glacier is a major contributor to global sea level rise
and has been losing massive amounts of ice for decades, accounting for 20 percent of the West Antarctic Ice Sheet's total ice loss
. An international research team says that the Pine Island Glacier has been losing 20 billion tons of ice annually for the past two decades and could lose 100 billion tons annually over the next 20 years. The glacier "has started a phase of self-sustained retreat and will irreversibly continue its decline," says Gael Durand, a glaciologist with France's Grenoble Alps University.
09 Jan 2014:
Faced With Sea Ice Loss,
Emperor Penguins Alter Breeding Tactics
Confronted with the loss of sea ice in some parts of Antarctica, four colonies of emperor penguins have come up with an innovative breeding strategy
to adapt to their changing environment. Using satellite images,
an international team of scientists tracked the four colonies from 2008 to 2012. In the first three years, the emperor penguins hatched and incubated eggs in their customary fashion — atop the sea ice that freezes during the Antarctic winter and spring. But in 2011 and 2012, sea ice did not form until a month after the breeding season began. As a result, the emperor penguins, which are the largest penguin species on earth, did something never before witnessed by scientists: They climbed the nearly sheer walls of large, floating ice shelves — huge structures, often hundreds of square miles in extent, that flow from land-based glaciers into the sea. In the region of the four colonies, the ice shelf walls reach as high as 100 feet. The scientists say the altered breeding behavior could demonstrate how ice-dependent emperor penguins may adapt to a warming world.
02 Jan 2014:
Stranded Antarctic Expedition
Rescued After Being Icebound for Nine Days
Passengers trapped on an icebound Russian research ship off the coast of Antarctica were rescued today after being stranded
for more than a week. A helicopter from China shuttled the 52 scientists, journalists, and tourists to an Australian icebreaker. The chartered ship was attempting to recreate the century-old travels and scientific work carried out by the East Antarctic research expedition led by Douglas Mawson in 1911. The Russian ship, which set out from New Zealand on December 8, became trapped in thick pack ice that even icebreakers could not penetrate. Because it was a privately chartered expedition, the voyage was not subjected to the same rigorous safety requirements that a research trip funded by government agencies would have been, scientists said. Some scientists contended that the lack of preparation sparked a rescue effort that diverted ships, crew, and other important resources
from other research efforts elsewhere in Antarctica.
31 Dec 2013:
Atlantic Ocean Zooplankton
Are Now Reproducing in Arctic Waters
For the first time, scientists have discovered species of Atlantic Ocean zooplankton reproducing in Arctic waters
. German researchers say the discovery indicates a possible shift in the Arctic zooplankton community as
The amphipod Themisto compressa
the region warms, one that could be detrimental to Arctic birds, fish, and marine mammals. Studying traps that have been suspended for 13 years in the Fram Strait, scientists from the Alfred Wegener Institute found that small species of crustaceans common to the Atlantic are increasingly moving into Arctic waters. The researchers found fertile females as well as individuals at all stages of development, showing that the Atlantic species is reproducing in the frigid waters. The one-centimeter amphipods are smaller than respective Arctic species, meaning that the spread of the Atlantic crustaceans northward could reduce the volume of food available to Arctic predators. The research was published in the journal Marine Ecology Progress Series
23 Dec 2013:
Russian Oil Giant Becomes
First in World to Pump Oil From Arctic
The Russian national oil company Gazprom has begun drilling for oil at a highly contested site in the Arctic
. The oil field, an offshore site in the Russian Arctic known as Prirazlomnoye, drew international attention in September when a contingent of Greenpeace members boarded the platform in protest and were jailed in Russia for two months before being granted amnesty last week. The project, which is several years behind schedule, is the first in Russian history aimed at "developing the resources of the Arctic shelf," Gazprom said. Environmental groups say that no company has the technology or resources to deal with a massive oil spill in the harsh conditions of the Arctic Ocean. The oil giant Shell had planned exploratory drilling in the Arctic off the coast of Alaska, but temporarily shelved those plans last year after a series of mishaps. Gazprom says it has taken all necessary precautions to deal with a spill, Mongabay reports.
08 Nov 2013:
Antarctic Researchers Discover
Strips of Rock That Slow Flow of Glaciers
Narrow ribs of dirt and rock beneath Antarctic glaciers help slow the glaciers' flow into the sea, according to new research
from scientists at Princeton University and the British Antarctic Survey. Using satellite measurements of the Pine Island Glacier and Thwaites
Glacier, both in West Antarctica, researchers discovered bands they call "tiger stripes" underlying the glaciers. The stripes serve as zones of friction and prevent sliding, much like non-slip flooring, the researchers report in Science
. Understanding the factors that control the glaciers' flow to the sea is important because their melting contributes significantly to sea level rise. The Pine Island and Thwaites glaciers are particularly important, as together they've contributed about 10 percent of the observed global sea level rise over the past 20 years.
09 Oct 2013:
Antarctic Research Operations
To Be Halted Amid U.S. Government Shutdown
The National Science Foundation (NSF) says it is curtailing the 2013-2014 Antarctic research season because the U.S. government shutdown has delayed funding for operations there. The U.S. Antarctic
Program, which is managed by the NSF, announced yesterday
that the three U.S. research stations, ships, and other facilities there will switch to "caretaker status" when funds are exhausted around October 14. All research activities not essential to human safety and preservation of property will be suspended, according to the statement. Because of the remote location and long lead time necessary for planning and travel, the NSF has already started the process of shuttering research facilities. Once funding is restored, some research operations could be restored, the U.S. Antarctic Program said. Around 700 scientists typically travel to the continent between October and February each year, according to Nature
13 Sep 2013:
Warmer Ocean Water Is Key
Factor in Melting Ice Shelves, Study Says
Recent research into one of West Antarctica's most rapidly melting glaciers and ice shelves has shown that rising ocean temperatures and a series of channels lacing the underside of
Edge of Pine Island ice sheet
the shelf are the key factors in the rapid thinning of the shelf
and the swift advance of the glacier behind it. Reporting in Science
, U.S. scientists said that instruments deployed on and under the Pine Island Glacier and ice shelf over the past two years have shown that warmer ocean water has been flowing through a series of channels under the shelf, causing the 31-mile-long floating slab of ice to thin at the alarming rate of 2.4 inches per day and loosening the shelf's hold on the bedrock below. The melting ice shelf itself doesn't contribute to sea level rise, but as it thins it allows more of the land-based Pine Island Glacier to flow into the sea,
which is contributing to sea level rise.
02 Aug 2013:
Prolonged Heat Wave Leaves
Russian Arctic Vulnerable to Wildfires
An enduring high-pressure weather system over the Russian Arctic has led to a prolonged heat wave, creating conditions for another surge in wildfires
a year after a particularly extreme wildfire season. NASA
scientists say that a so-called “blocking high” system — in which rain-bearing systems are blocked from moving west to east — has caused temperatures to reach 90 degrees F (32 degrees C) in the northern city of Norlisk, where daily highs in July typically average 61 degrees F (16 degrees C). Using satellite data, NASA produced a map that vividly depicts the land surface temperature anomalies in the region during the week of July 20-27, with temperatures soaring as high as 37 degrees F above normal. A separate satellite image shows smoke billowing from several fires burning in one of the areas, in the Khanty-Mansiyskiy and Yamal-Nenetskiy districts. According to scientists, the Siberian fires are burning in areas far north of where summer wildfires typically occur.
16 Jul 2013:
Russia Blocks Plans to Create
Massive Marine Reserve in Antarctica
Russian officials have blocked plans to establish the world’s largest marine reserve
in the waters off Antarctica, citing concerns that it would restrict their
John B. Weller/The Pew Charitable Trusts
Ross Sea pack ice
fishing interests in the region, according to news reports. The plan, which was proposed by the U.S. and New Zealand, would have protected a total of 2.3 million square miles in the Ross Sea, a deep, high-latitude body of water in the Southern Ocean. But during a meeting of the 25-member Commission for Conservation of Antarctic Marine Living Resources, Russia questioned whether the organization had the legal right to create such a haven. A key sticking point for the Russians was the potential loss of the fishery for krill, a shrimp-like creature that is a critical food source for penguins, seabirds, seals, and whales, but is netted for use in Omega-3 dietary supplements.
10 Jul 2013:
Massive Iceberg Calves
Off Antarctica’s Pine Island Glacier
A massive chunk of Antarctica’s fastest-moving ice stream, the Pine Island Glacier, dropped into the Amundsen Sea this week
, nearly two years after
Click to enlarge
Alfred Wegener Institute/German Space Agency
Pine Island Glacier, 2011-2013
scientists first observed a crack in the glacier tongue. German scientists, who have been tracking the progress of the ice mass since NASA satellites first observed the crack in 2011, say the calved iceberg measured 720 square kilometers (278 square miles). There is no conclusive proof that climate change triggered the ice break, said Angelika Humbert, an ice researcher at the Alfred Wegener Institute. But shifting wind patterns around Antarctica are bringing warmer waters to the surface of the Southern Ocean in West Antarctica, which is hastening the thinning of some glaciers. Humbert said those warmer waters are causing the Pine Island Glacier to flow more rapidly into the Amundsen Sea.
20 Jun 2013:
Global Reports Underline
Threats to Planet’s Bird Species
New global research underlines the rising threats facing the world’s bird species, with three reports providing evidence that climate change, overfishing, and unsustainable agriculture are taking a heavy toll on
Puffins along the Maine coast.
avian populations worldwide. The U.S. Fish and Wildlife Service (FWS) reports that numbers of some migratory bird populations in Maine — including Arctic terns and puffins — have plummeted in recent years
because their food supplies are disappearing as a result of commercial fishing and the shifting of fish to cooler waters, which is making it more difficult for some birds to feed their young. In a separate study, scientists predict that rising sea levels will devastate habitat for some migratory shore birds
in the coming decades. Higher sea levels, the study predicts, will flood 23 percent to 40 percent of the intertidal habitats for several shorebird species, triggering population declines of as much as 70 percent. Overall, one in eight bird species globally is at risk of extinction
, according to a new report by BirdLife International
17 Jun 2013:
Changes in Jet Stream Triggered
Record Greenland Melt in 2012, Study Says
An unusual shift in the jet stream triggered the historic level of surface ice melt
that occurred across Greenland last summer, a new study says. Using satellite data and a computer model simulation, scientists from the University of Sheffield found that a high-pressure system developed in the mid-troposphere over Greenland for much of the summer, pushing warm southerly winds over the western edge of the ice sheet and creating a “heat dome” over Greenland. According to the study, published in the International Journal of Climatology
, this unprecedented event caused record melting across virtually the entire ice sheet, including on Summit Station, Greenland’s highest peak. Ocean temperatures and Arctic sea ice retreat, meanwhile, played a minimal part in the record surface ice melt, the scientists reported. The study predicted that the record ice melt of 2012 is not likely to be “climatically representative of future ‘average’ summers” during the coming century.
07 Jun 2013:
New Map of Antarctica Provides
Clearest Glimpse of Subglacial Continent
British scientists have unveiled the most detailed topographical map available yet of Antarctica
, a vast dataset that provides a penetrating 3-D view of the
Click to enlarge
NASA Goddard Space Flight Center
Antarctica's subglacial terrain
frozen continent down to the bedrock level and could offer insights into how it will respond to climate change. Based on millions of measurements collected over decades, the British Antarctic Survey
’s Bedmap2 project illustrates the continent with a level of clarity not previously available, including a vivid look at the mountain landscapes buried in ice and valleys that run deeper than had been known. The scientists say better understanding the landscape will help them predict the behavior of Antarctica’s ice sheet in future decades and the extent to which melting could increase sea levels. The map was based on data collected by satellites, land-based surveys, and ice-penetrating measurements of the subglacial bedrock