Turning Up the Temperature in the High Arctic
Al Werner on his way to the day's research site in Svalbard, Norway
Al Werner is feeling the heat this summer. Typically, that wouldn’t be a problem to alleviate; a jump in the pool or a visit to the movie theatre would cool things down. But there weren’t pools or movie theatres in the Norwegian Arctic, where Werner just finished conducting research as part of the Svalbard Research Experience for Undergraduates (REU). There were, however, glaciers–and, as the Mount Holyoke professor of geology found, they’re melting. Quickly.
“There is clear evidence of climate change here,” Werner said via email from Svalbard. “The Linne´ Glacier has been retreating since 1936 at an average rate of 20 meters per year. Since 2002, that rate has increased twofold, to nearly 40 meters per year. Now, we’re seeing the return of warm-water-loving mollusks. These results are consistent with other Arctic regions that likewise show accelerated warming in the past two decades.”
It’s an alarming trend that the REU is monitoring in the Norwegian High Arctic. The project’s ultimate goals are to monitor the area’s glacier/river/lake system, and to provide a better understanding of natural (pre-industrial) climate change there.
The Svalbard research is just one part of the much larger REU program, funded by the National Science Foundation, that aims to attract undergraduates to scientific fields by immersing them in field research experiences. In this way, Werner says, his REU project is mainly about educating and, hopefully, inspiring tomorrow’s climate change scientists. (more…)
Is the Ice in the Arctic Ocean Getting Thinner and Thinner?
Propeller of Polar 5, the scientific aircraft of Alfred Wegener Institute, on its flight across Svalbard. (Photo: Ralf Röchert, Alfred Wegener Institute)
The extent of the sea ice in the Arctic will reach its annual minimum in September. Forecasts indicate that it will not be as low as in 2007, the year of the smallest area covered by sea ice since satellites started recording such data. Nevertheless, sea ice physicists at the Alfred Wegener Institute are concerned about the long-term equilibrium in the Arctic Ocean.
They have indications that the mass of sea ice is dwindling because its thickness is declining. To substantiate this, they are currently measuring the ice thickness north and east of Greenland using the research aircraft Polar 5. The objective of the roughly one-week campaign is to determine the export of sea ice from the Arctic. Around a third to half of the freshwater export from the Arctic Ocean takes place in this way – a major drive factor in the global ocean current system.
The question of when the Arctic will be ice-free in the summer has been preoccupying the sea ice researchers headed by Prof. Dr. Rüdiger Gerdes from the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association for a long time now. (more…)
Ice Core Drilling Effort Will Help Assess Abrupt Climate Change Risks
An international drilling team involving CU-Boulder has hit bedrock 1.5 miles below the icy surface of Greenland, pulling up deep ice cores from the last interglacial period that should help climate scientists assess the risks of abrupt climate change on a warming Earth. (Image courtesy NEEM ice core drilling project)
An international science team involving the University of Colorado at Boulder that is working on the North Greenland Eemian Ice Drilling project hit bedrock July 27 after two summers of work, drilling down more than 1.5 miles in an effort to help assess the risks of abrupt future climate change on Earth.
Led by Denmark and the United States, the team recovered ice from the Eemian interglacial period from about 115,000 to 130,000 years ago, a time when temperatures were 3.6 to 5.4 degrees Fahrenheit above today’s temperatures. During the Eemian — the most recent interglacial period on Earth — there was substantially less ice on Greenland, and sea levels were more than 15 feet higher than today.
While three previous ice cores drilled in Greenland in the last 20 years recovered ice from the Eemian, the deepest layers were compressed and folded, making the data difficult to interpret. The new effort, known as NEEM, has allowed researchers to obtain thicker, more intact annual ice layers near the bottom of the core that are expected to contain crucial information about how Earth’s climate functions, said CU-Boulder Professor Jim White, lead U.S. investigator on the project.
“Scientists from 14 countries have come together in a common effort to provide the science our leaders and policy makers need to plan for our collective future,” said White, who directs CU-Boulder’s Institute of Arctic and Alpine Research and is an internationally known ice core expert. “I hope that NEEM is a foretaste of the kind of cooperation we need for the future, because we all share the world.” (more…)
Ice-Free Ocean May Not Absorb CO2, A Component in Global Warming
by Philip Lee Williams
A Chinese-American research team working in the Arctic has found that the melted waters in summer may be less help in absorbing atmospheric carbon dioxide than earlier thought. Photo taken by Dr. Jianfang Chen, State Ocean Administration of China - Second Institute of Oceanography, Hangzhou, China.
The summer of 2010 has been agonizingly hot in much of the continental U.S., and the record-setting temperatures have refocused attention on global warming. Scientists have been looking at ways the Earth might benefit from natural processes to balance the rising heat, and one process had intrigued them, a premise that melting ice at the poles might allow more open water that could absorb carbon dioxide, one of the major compounds implicating in warming.
Now, though, in research just published in the journal Science and led by a University of Georgia marine chemist, that idea may be one more dead end. In fact, a survey of waters in the Canada Basin, which extends north of Alaska to the North Pole, shows that its value as a potential carbon dioxide “sink” may be short-lived at best and minor in terms of what the planet will need to avoid future problems.
“The Canada Basin and entire Arctic Ocean are still taking up carbon dioxide,” said Wei-Jun Cai, a professor in the department of marine sciences in UGA’s Franklin College of Arts and Sciences and lead author of the study. “But our research shows that as the ice melts, the carbon dioxide in the water very quickly reaches equilibrium with the atmosphere, so its use as a place to store CO2 declines dramatically and quickly. We never really understood how limited these waters would be in terms of their usefulness in soaking up carbon dioxide.” (more…)
Permafrost Warming, Monitoring Improving
University of Alaska Fairbanks Professor Vladimir Romanovsky measures permafrost temperature at a borehole in interior Alaska. (Credit: Photo by A. Kholodov)
Permafrost warming continues throughout a wide swath of the Northern Hemisphere, according to a team of scientists assembled during the recent International Polar Year.
Their extensive findings, published in the April-June 2010 edition of Permafrost and Periglacial Processes, describe the thermal state of high-latitude permafrost during the International Polar Year, 2007-2009. Vladimir Romanovsky, a professor with the snow, ice and permafrost group at the University of Alaska Fairbanks Geophysical Institute, is the lead author of the paper, which also details the significant expansion of Northern Hemisphere permafrost monitoring.
“This paper is actually pretty unique,” Romanovsky said, “because it’s the first time such a large geographical area has been involved in one paper.”
During the International Polar Year, Romanovsky and his colleagues launched a field campaign to improve the existing permafrost-monitoring network. The permafrost thermal state is monitored with borehole sensors, which gather data from holes drilled deep into the permafrost. The researchers established nearly 300 borehole sites that serve as permafrost observatories across the polar and sub-polar regions in the Northern Hemisphere. Their work more than doubled the size of the previously existing network
“The heart of monitoring is the measuring of temperatures in boreholes,” Romanovsky said. “For permafrost temperatures, you have to be there. You have to establish boreholes.” (more…)
Best Hope for Saving Arctic Sea Ice is Cutting Soot Emissions, Says Stanford Researcher
By Jess McNally
Mark Jacobson found that eliminating soot produced by the burning of fossil fuel and solid biofuel could reduce warming above parts of the Arctic Circle in the next 15 years by up to 1.7 degrees Celsius.
The quickest, best way to slow the rapid melting of Arctic sea ice is to reduce soot emissions from the burning of fossil fuel, wood and dung, according to a new study by Stanford researcher Mark Z. Jacobson.
His analysis shows that soot is second only to carbon dioxide in contributing to global warming. But, he said, climate models to date have mischaracterized the effects of soot in the atmosphere.
Because of that, soot’s contribution to global warming has been ignored in national and international global warming policy legislation, he said.
“Controlling soot may be the only method of significantly slowing Arctic warming within the next two decades,” said Jacobson, director of Stanford’s Atmosphere/Energy Program. “We have to start taking its effects into account in planning our mitigation efforts and the sooner we start making changes, the better.”
To reach his conclusions, Jacobson used an intricate computer model of global climate, air pollution and weather that he developed over the last 20 years that included atmospheric processes not incorporated in previous models. (more…)
Arctic Climate May Be More Sensitive to Warming Than Thought, Says New Study
From left to right, Ashley Ballantyne of the University of Colorado at Boulder, Dara Finney of Environment Canada and Natalia Rybczynski of the Canadian Museum of Nature search for fossils in a peat deposit at Strathcona Fiord on Ellesmere Island in Canada's High Arctic. (Photo courtesy Dara Finney, Environment Canada)
A new study shows the Arctic climate system may be more sensitive to greenhouse warming than previously thought, and that current levels of Earth’s atmospheric carbon dioxide may be high enough to bring about significant, irreversible shifts in Arctic ecosystems.
Led by the University of Colorado at Boulder, the international study indicated that while the mean annual temperature on Ellesmere Island in the High Arctic during the Pliocene Epoch 2.6 to 5.3 million years ago was about 34 degrees Fahrenheit, or 19 degrees Celsius, warmer than today, CO2 levels were only slightly higher than present. The vast majority of climate scientists agree Earth is warming due to increased concentrations of heat-trapping atmospheric gases generated primarily by human activities like fossil fuel burning and deforestation.
The team used three independent methods of measuring the Pliocene temperatures on Ellesmere Island in Canada’s High Arctic. They included measurements of oxygen isotopes found in the cellulose of fossil trees and mosses that reveal temperatures and precipitation levels tied to ancient water, an analysis of the distribution of lipids in soil bacteria which correlate with temperature, and an inventory of ancient Pliocene plant groups that overlap in range with contemporary vegetation. (more…)
The Vanishing Face of Gaia - Dr. James Lovelock Video
Corporate Knights presents Dr. James Lovelock, originator of The Gaia Hypothesis (also known as Gaia Theory), discussing the need for human adaptation and survival in a coming era of massive environmental change due to global heating based on his latest book, “The Vanishing Face of Gaia”.
Biography:
(Excerpted from Wikipedia)
A lifelong inventor, Lovelock has created and developed many scientific instruments, some of which were designed for NASA in its program of planetary exploration. It was while working as a consultant for NASA that Lovelock developed the Gaia Hypothesis, for which he is most widely known.
In early 1961, Lovelock was engaged by NASA to develop sensitive instruments for the analysis of extraterrestrial atmospheres and planetary surfaces. The Viking program, that visited Mars in the late 1970s, was motivated in part to determine whether Mars supported life, and many of the sensors and experiments that were ultimately deployed aimed to resolve this issue. During work on a precursor of this program, Lovelock became interested in the composition of the Martian atmosphere, reasoning that many life forms on Mars would be obliged to make use of it (and, thus, alter it). However, the atmosphere was found to be in a stable condition close to its chemical equilibrium, with very little oxygen, methane, or hydrogen, but with an overwhelming abundance of carbon dioxide. To Lovelock, the stark contrast between the Martian atmosphere and chemically dynamic mixture of that of our Earth’s biosphere was strongly indicative of the absence of life on the planet.[ However, when they were finally launched to Mars, the Viking probes still searched (unsuccessfully) for extant life there.
Lovelock invented the electron capture detector, which ultimately assisted in discoveries about the persistence of CFCs and their role in stratospheric ozone depletion. After studying the operation of the Earth’s sulfur cycle, Lovelock and his colleagues developed the CLAW hypothesis as a possible example of biological control of the Earth’s climate.
After the development of his electron capture detector, in the late 1960s, Lovelock was the first to detect the widespread presence of CFCs in the atmosphere. He found a concentration of 60 parts per trillion of CFC-11 over Ireland and, in a partially self-funded research expedition in 1972, went on to measure the concentration of CFC-11 from the northern hemisphere to the Antarctic aboard the research vessel RRS Shackleton. He found the gas in each of the 50 air samples that he collected but, not realising that the breakdown of CFCs in the stratosphere would release chlorine that posed a threat to the ozone layer, concluded that the level of CFCs constituted “no conceivable hazard”. He has since stated that he meant “no conceivable toxic hazard”.
However, the experiment did provide the first useful data on the ubiquitous presence of CFCs in the atmosphere. The damage caused to the ozone layer by the photolysis of CFCs was later discovered by Sherwood Rowland and Mario Molina. After hearing a lecture on the subject of Lovelock’s results, they embarked on research that resulted in the first published paper that suggested a link between stratospheric CFCs and ozone depletion in 1974, and later shared the 1995 Nobel Prize in Chemistry for their work.
Gaia hypothesis
First formulated by Lovelock during the 1960s as a result of work for NASA concerned with detecting life on Mars, the Gaia hypothesis proposes that living and non-living parts of the earth form a complex interacting system that can be thought of as a single organism. Named after the Greek goddess Gaia at the suggestion of novelist William Golding, the hypothesis postulates that the biosphere has a regulatory effect on the Earth’s environment that acts to sustain life.
While the Gaia hypothesis was readily accepted by many in the environmentalist community, it has not been widely accepted within the scientific community. Among its more famous critics are the evolutionary biologists Richard Dawkins, Ford Doolittle, and Stephen Jay Gould — notable, given the diversity of this trio’s views on other scientific matters. These (and other) critics have questioned how natural selection operating on individual organisms can lead to the evolution of planetary-scale homeostasis.
Lovelock has responded to these criticisms with models such as Daisyworld, that illustrate how individual-level effects can translate to planetary homeostasis, under the right circumstances.
Nuclear power
Lovelock has become concerned about the threat of global warming from the greenhouse effect. In 2004 he caused a media sensation when he broke with many fellow environmentalists by pronouncing that “only nuclear power can now halt global warming”. In his view, nuclear energy is the only realistic alternative to fossil fuels that has the capacity to both fulfill the large scale energy needs of humankind while also reducing greenhouse emissions. He is an open member of Environmentalists for Nuclear Energy.
In 2005, against the backdrop of renewed UK government interest in nuclear power, Lovelock again publicly announced his support for nuclear energy, stating, “I am a Green, and I entreat my friends in the movement to drop their wrongheaded objection to nuclear energy”. Although these interventions in the public debate on nuclear power are recent, his views on it are longstanding. In his 1988 book The Ages of Gaia he states:
“I have never regarded nuclear radiation or nuclear power as anything other than a normal and inevitable part of the environment. Our prokaryotic forebears evolved on a planet-sized lump of fallout from a star-sized nuclear explosion, a supernova that synthesised the elements that go to make our planet and ourselves.”
James Lovelock in conversation with science editor Tim Radford.
Climate Change Scientists Turn Up the Heat in Alaska
A DOE study will test the impact of increased temperature on Arctic tundra. (Photo provided by researcher Stan Wullschleger)
Scientists at the Department of Energy’s Oak Ridge National Laboratory are planning a large-scale, long-term ecosystem experiment to test the effects of global warming on the icy layers of arctic permafrost.
While ORNL researchers have conducted extensive studies on the impact of climate change in temperate regions like East Tennessee, less is known about the impact global warming could have on arctic regions.
“We’re beginning to take these lessons learned and start applying them to sensitive and globally important ecosystems, such as the arctic,” said Stan Wullschleger of the Environmental Sciences Division. “The arctic regions are important to the topic of global warming because of the large land area they occupy around the world and the layer of permanently frozen soil, known as permafrost.”
Wullschleger and a team of architects, engineers and biologists from ORNL and other national laboratories design, simulate using computers and then field test large-scale manipulative experiments that purposely warm a test area in order to evaluate ecosystem response to projected climate conditions. (more…)
Arctic Sea Ice Predictions Uncertain This Year
A critical minimum for Arctic sea ice can also be expected for late summer 2010. Scientists from the German “Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association (AWI)” in Bremerhaven and from “KlimaCampus” of the University of Hamburg have now published their projections in the current Sea Ice Outlook. The online publication compares the forecasts on ice cover for September 2010 prepared by around a dozen international research institutes in a scientific “competition”. The ice reaches its minimum area at this time every year.
The forecast developed by the team from KlimaCampus of the University of Hamburg, i.e. 4.7 million square kilometres (km2), is more negative than that submitted by the AWI researchers, who arrived at a figure of 5.2 million km2. Nevertheless, neither of the two research groups anticipates that the record minimum of 4.3 million km2 in 2007 will be reached.
Although Arctic ice currently has an area of ten million km2, which is half a million km2 smaller than in 2007, one cannot directly conclude a new record minimum in late summer. The present ice cover is comparable to that in June 2006, a year when more ice area remained in September than in 2007. The decisive factors for the situation in late summer, such as the ice thickness in the central Arctic and further development of the weather in summer, are not yet known, however. (more…)
Arctic Ice at Low Point Compared to Recent Geologic History
by Pam Frost Gorder
Leonid Polyak
Less ice covers the Arctic today than at any time in recent geologic history.
That’s the conclusion of an international group of researchers, who have compiled the first comprehensive history of Arctic ice.
For decades, scientists have strived to collect sediment cores from the difficult-to-access Arctic Ocean floor, to discover what the Arctic was like in the past. Their most recent goal: to bring a long-term perspective to the ice loss we see today.
Now, in an upcoming issue of Quarternary Science Reviews, a team led by Ohio State University has re-examined the data from past and ongoing studies — nearly 300 in all — and combined them to form a big-picture view of the pole’s climate history stretching back millions of years.
“The ice loss that we see today — the ice loss that started in the early 20th Century and sped up during the last 30 years — appears to be unmatched over at least the last few thousand years,” said Leonid Polyak, a research scientist at Byrd Polar Research Center at Ohio State University. Polyak is lead author of the paper and a preceding report that he and his coauthors prepared for the U.S. Climate Change Science Program. (more…)
Observations on Climate Change in the Arctic - WWF Video
Over the last several years we have seen a drastic reduction in sea ice in the arctic region of the world. Scientist project that the summer sea ice cover of the Arctic Ocean might be lost within a decade. Half of the heat produced on earth is created in the Arctic, resulting in accelerates climate change.
Greenland Rapidly Rising as Ice Melt Continues
This is a satellite image of Western Greenland, acquired by NASA's MODIS satellite. The narrow grey band in the center of the image is melting ice, between the rocky coast to the left (west) and thicker, non-melting, higher altitude ice to the right (east). Small lakes form in this region during the summer. Arrow points to darker grey zone of rapidly thinning ice near the outlet of Jacobshavn glacier, which also loses mass due to iceberg calving. (Courtesy of NASA)
Greenland is situated in the Atlantic Ocean to the northeast of Canada. It has stunning fjords on its rocky coast formed by moving glaciers, and a dense icecap up to 2 km thick that covers much of the island–pressing down the land beneath and lowering its elevation. Now, scientists at the University of Miami say Greenland’s ice is melting so quickly that the land underneath is rising at an accelerated pace.
According to the study, some coastal areas are going up by nearly one inch per year and if current trends continue, that number could accelerate to as much as two inches per year by 2025, explains Tim Dixon, professor of geophysics at the University of Miami Rosenstiel School of Marine and Atmospheric Science (RSMAS) and principal investigator of the study.
“It’s been known for several years that climate change is contributing to the melting of Greenland’s ice sheet,” Dixon says. “What’s surprising, and a bit worrisome, is that the ice is melting so fast that we can actually see the land uplift in response,” he says. “Even more surprising, the rise seems to be accelerating, implying that melting is accelerating.”
Dixon and his collaborators share their findings in a new study titled “Accelerating uplift in the North Atlantic region as an indicator of ice loss,” The paper is now available as an advanced online publication, by Nature Geoscience. The idea behind the study is that if Greenland is losing its ice cover, the resulting loss of weight causes the rocky surface beneath to rise. The same process is affecting the islands of Iceland and Svalbard, which also have ice caps, explains Shimon Wdowinski, research associate professor in the University of Miami RSMAS, and co-author of the study. (more…)
Melting Sea Ice Major Cause of Warming in Arctic, New Study Reveals
Melting sea ice has been shown to be a major cause of warming in the Arctic according to a University of Melbourne, Australia study.
Findings published in Nature today reveal the rapid melting of sea ice has dramatically increased the levels of warming in the region in the last two decades.
Lead author Dr James Screen of the School of Earth Sciences at the University of Melbourne says the increased Arctic warming was due to a positive feedback between sea ice melting and atmospheric warming.
“The sea ice acts like a shiny lid on the Arctic Ocean. When it is heated, it reflects most of the incoming sunlight back into space. When the sea ice melts, more heat is absorbed by the water. The warmer water then heats the atmosphere above it. ”
“What we found is this feedback system has warmed the atmosphere at a faster rate than it would otherwise,” he says. (more…)
Deepest Antarctic Drill Core May Contain Ice Age Ice
Ellen Mosley-Thompson
If so, that record should give new insight into past global climate changes.
Researchers here are hopeful that the new core they drilled through an ice field on the Antarctic Peninsula will contain ice dating back into the last ice age. If so, that record should give new insight into past global climate changes.
The expedition in early winter to the Bruce Plateau, an ice field straddling a narrow ridge on the northernmost tongue of the southernmost continent, yielded a core that was 445.6 meters (1,462 feet) long, the longest yet recovered from that region of Antarctica.
And while remarkably successful, the field work tested the researchers’ resilience more than most of their previous expeditions.
“It was the field season from hell,” explained Ellen Mosley-Thompson, professor of geography at Ohio State University and leader of the project. “Everything that could go wrong did, and almost everything that could break did.” (more…)
Decades of Research Show Massive Arctic Ice Cap is Shrinking
Close to 50 years of data show the Devon Island ice cap, one of the largest ice masses in the Canadian High Arctic, is thinning and shrinking.
A paper published in the March edition of Arctic, the journal of the University of Calgary’s Arctic Institute of North America, reports that between 1961 and 1985, the ice cap grew in some years and shrank in others, resulting in an overall loss of mass. But that changed 1985 when scientists began to see a steady decline in ice volume and area each year.
“We’ve been seeing more mass loss since 1985,” says Sarah Boon, lead author on the paper and a Geography Professor at the University of Lethbridge. The reason for the change? Warmer summers.
The High Arctic is essentially a desert with low rates of annual precipitation. There is little accumulation of snow in the winter and cool summers, with temperatures at or below freezing, serve to maintain levels. Any increase of snow and ice takes years.
This delicate equilibrium is easily upset. One warm summer can wipe out five years of growth. And though the accelerated melting trend began in 1985, the last decade has seen four years with unusually warm summers - 2001, 2005, 2007 and 2008. (more…)
Successful Launch for ESA’s CryoSat-2 Ice Satellite
Europe's first mission dedicated to studying the Earth’s ice was launched today from Kazakhstan. From its polar orbit, CryoSat-2 will send back data leading to new insights into how ice is responding to climate change and the role it plays in our ‘Earth system’. (ESA)
Europe’s first mission dedicated to studying the Earth’s ice was launched today from Kazakhstan. From its polar orbit, CryoSat-2 will send back data leading to new insights into how ice is responding to climate change and the role it plays in our ‘Earth system’.
The CryoSat-2 satellite was launched at 15:57 CEST (13:57 UTC) on a Dnepr rocket provided by the International Space Company Kosmotras from the Baikonur Cosmodrome in Kazakhstan. The signal confirming that it had separated from the launcher came 17 minutes later from the Malindi ground station in Kenya.
CryoSat-2 replaces the original CryoSat satellite that was lost in 2005 owing to a launch failure. The mission objectives, however, remain the same: to measure changes in the thickness of the vast ice sheets that overlie Antarctica and Greenland, as well as variations in the thickness of the relatively thin ice floating in the polar oceans.
“We know from our radar satellites that sea ice extent is diminishing, but there is still an urgent need to understand how the volume of ice is changing,” said Volker Liebig, ESA’s Director of Earth Observation Programmes. “To make these calculations, scientists also need information on ice thickness, which is exactly what our new CryoSat satellite will provide. We are now very much looking forward to receiving the first data from the mission.” (more…)
Greenland Ice Sheet Losing Mass on Northwest Coast
Shfaqat Abbas Khan - Tasiilaq, Greenland
Ice loss from the Greenland ice sheet, which has been increasing during the past decade over its southern region, is now moving up its northwest coast, according to a new international study.
Led by the Denmark Technical Institute’s National Space Institute in Copenhagen and involving the University of Colorado at Boulder, the study indicated the ice-loss acceleration began moving up the northwest coast of Greenland starting in late 2005. The team drew their conclusions by comparing data from NASA’s Gravity and Recovery Climate Experiment satellite system, or GRACE, with continuous GPS measurements made from long-term sites on bedrock on the edges of the ice sheet.
The data from the GPS and GRACE provided the researchers with monthly averages of crustal uplift caused by ice-mass loss. The team combined the uplift measured by GRACE over United Kingdom-sized chunks of Greenland while the GPS receivers monitor crustal uplift on scales of just tens of miles. “Our results show that the ice loss, which has been well documented over southern portions of Greenland, is now spreading up along the northwest coast,” said Shfaqat Abbas Khan, lead author on a paper that will appear in Geophysical Research Letters. (more…)
High Arctic Species in Decline Due to Changing Ecosystems
Louise McRae - Living Planet Index Postgraduate Research Assistant
A new assessment of the Arctic’s biodiversity reports a 26 per cent decline in species populations in the high Arctic.
Populations of lemmings, caribou and red knot are some of the species that have experienced declines over the past 34 years, according to the first report from The Arctic Species Trend Index (ASTI), which provides crucial information on how the Arctic’s ecosystems and wildlife are responding to environmental change.
While some of these declines may be part of a natural cycle, there is concern that pressures such as climate change may be exacerbating natural cyclic declines.
In contrast, population levels of species living in the sub-Arctic and low Arctic are relatively stable and in some cases, increasing. Populations of marine mammals, including bowhead whales found in the low Arctic, may have benefited from the recent tightening of hunting laws. Some fish species have also experienced population increases in response to rising sea temperatures.
“Rapid changes to the Arctic’s ecosystems will have consequences for the Arctic that will be felt globally. The Arctic is host to abundant and diverse wildlife populations, many of which migrate annually from all regions of the globe. This region acts as a critical component in the Earth’s physical, chemical, and biological regulatory system,” says lead-author Louise McRae from the Zoological Society of London (ZSL). (more…)
Methane Releases from Arctic Shelf May Be Much Larger and Faster Than Anticipated
A section of the Arctic Ocean seafloor that holds vast stores of frozen methane is showing signs of instability and widespread venting of the powerful greenhouse gas, according to the findings of an international research team led by University of Alaska Fairbanks scientists Natalia Shakhova and Igor Semiletov.
The research results, published in the March 5 edition of the journal Science, show that the permafrost under the East Siberian Arctic Shelf, long thought to be an impermeable barrier sealing in methane, is perforated and is starting to leak large amounts of methane into the atmosphere. Release of even a fraction of the methane stored in the shelf could trigger abrupt climate warming.
“The amount of methane currently coming out of the East Siberian Arctic Shelf is comparable to the amount coming out of the entire world’s oceans,” said Shakhova, a researcher at UAF’s International Arctic Research Center. “Subsea permafrost is losing its ability to be an impermeable cap.”
Methane is a greenhouse gas more than 30 times more potent than carbon dioxide. It is released from previously frozen soils in two ways. When the organic material (which contains carbon) stored in permafrost thaws, it begins to decompose and, under anaerobic conditions, gradually releases methane. Methane can also be stored in the seabed as methane gas or methane hydrates and then released as subsea permafrost thaws. These releases can be larger and more abrupt than those that result from decomposition. (more…)
Ice Shelves Disappearing on Antarctic Peninsula
This image shows ice-front retreat in part of the southern Antarctic Peninsula from 1947 to 2009. USGS scientists are studying coastal and glacier change along the entire Antarctic coastline. The southern portion of the Antarctic Peninsula is one area studied as part of this project. (U.S. Geological Survey)
Ice shelves are retreating in the southern section of the Antarctic Peninsula due to climate change. This could result in glacier retreat and sea-level rise if warming continues, threatening coastal communities and low-lying islands worldwide.
Research by the U.S. Geological Survey is the first to document that every ice front in the southern part of the Antarctic Peninsula has been retreating overall from 1947 to 2009, with the most dramatic changes occurring since 1990. The USGS previously documented that the majority of ice fronts on the entire Peninsula have also retreated during the late 20th century and into the early 21st century.
The ice shelves are attached to the continent and already floating, holding in place the Antarctic ice sheet that covers about 98 percent of the Antarctic continent. As the ice shelves break off, it is easier for outlet glaciers and ice streams from the ice sheet to flow into the sea. The transition of that ice from land to the ocean is what raises sea level.
“This research is part of a larger ongoing USGS project that is for the first time studying the entire Antarctic coastline in detail, and this is important because the Antarctic ice sheet contains 91 percent of Earth’s glacier ice,” said USGS scientist Jane Ferrigno. “The loss of ice shelves is evidence of the effects of global warming. We need to be alert and continually understand and observe how our climate system is changing.” (more…)
Team Finds Subtropical Waters Flushing Through Greenland Fjord
Fiamma Straneo from the physical oceanography department at Woods Hole Oceaonographic Institution, at work on the deck of the Arctic Sunrise. (© Greenpeace/ Nick Cobbing)
Waters from warmer latitudes — or subtropical waters — are reaching Greenland’s glaciers, driving melting and likely triggering an acceleration of ice loss, reports a team of researchers led by Fiamma Straneo, a physical oceanographer from the Woods Hole Oceanographic Institution (WHOI).
“This is the first time we’ve seen waters this warm in any of the fjords in Greenland,” says Straneo. “The subtropical waters are flowing through the fjord very quickly, so they can transport heat and drive melting at the end of the glacier.”
Greenland’s ice sheet, which is two-miles thick and covers an area about the size of Mexico, has lost mass at an accelerated rate over the last decade. The ice sheet’s contribution to sea level rise during that time frame doubled due to increased melting and, to a greater extent, the widespread acceleration of outlet glaciers around Greenland.
While melting due to warming air temperatures is a known event, scientists are just beginning to learn more about the ocean’s impact — in particular, the influence of currents — on the ice sheet.
“Among the mechanisms that we suspected might be triggering this acceleration are recent changes in ocean circulation in the North Atlantic, which are delivering larger amounts of subtropical waters to the high latitudes,” says Straneo. But a lack of observations and measurements from Greenland’s glaciers prior to the acceleration made it difficult to confirm. (more…)
Measurement Flights in the Arctic Polar Vortex Will Help Predict Ozone Depletion
The research aircraft "M55 Geophysica" is one of three aircraft worldwide that can fly at altitudes of up to 21 kilometres. (Photo: Forschungszentrum Jülich)
An international measurement campaign began yesterday in the northern Swedish city of Kiruna. The campaign aims to clarify unanswered questions related to polar ozone depletion in the stratosphere. Measurement flights at altitudes of up to 20 kilometres will provide researchers with data for global climate models, which they will then use to make even more accurate predictions of the future development of the ozone layer and to determine the impact on climate.
The campaign, which will last several weeks, is part of the EU project “RECONCILE” involving 17 partners from nine countries. RECONCILE is coordinated by scientists from Forschungszentrum Jülich, member of the Helmholtz Association of German Research Centres.
“We know what processes deplete ozone in the stratosphere but we don’t know how fast these processes are. This is what we now want to measure with our partners,” says RECONCILE coordinator Marc von Hobe from Forschungszentrum Jülich. Every winter, what is known as the polar vortex forms in the Arctic.
In this vortex, the air in the stratosphere circulates around the pole and is thus isolated from air masses at lower latitudes. Extremely low temperatures in the polar vortex lead to the formation of polar stratospheric clouds. These in turn accelerate the formation of chlorine radicals, small molecules that deplete ozone, and in extreme cases, lead to the hole in the ozone layer. (more…)
Ice Mission Satellite Arrives Safely at Launch Site
CryoSat-2 arrives safely at Baikonur launch site in Kazakhstan on 13 January. (ESA/W.Simpson)
In what might seem rather appropriate weather conditions, the CryoSat-2 Earth Explorer satellite has completed its journey to the Baikonur launch site in Kazakhstan, where it will be prepared for launch on 25 February.
The satellite and support equipment left the ‘IABG’ test centre in Ottobrunn, Germany, by lorry on 12 January. The CryoSat mission is dedicated to precise monitoring of the changes in the thickness of marine ice floating in the polar oceans and variations in the thickness of the vast ice sheets that overlay Greenland and Antarctica. With much of Europe still in the grip of one of the coldest winters for some years, the icy conditions aptly set the stage for this first leg of CryoSat-2’s journey.
After arriving at Munich airport, the containers were loaded onto an Antonov aircraft. Along with team members from ESA and their industrial partner for CryoSat-2, EADS-Astrium, the Antonov took off in the early evening bound for Ulyanovsk, a city some 900 km east of Moscow, Russia. Once through customs clearance at Ulyanovsk, the aircraft continued the journey to the Baikonur Cosmodrome.
The weather was –12°C and fine on arrival. Safely cocooned in its thermally controlled container, CryoSat-2 and accompanying cargo were offloaded and moved to the integration facility. The launch campaign team will now spend the next six weeks preparing the satellite for launch. CryoSat-2 will be launched by a Dnepr rocket – a converted intercontinental ballistic missile – on 25 February at 14:57 CET (13:57 UT). (more…)
Loading... 
