Huge iceberg breaks away from the Pine Island glacier in the Antarctic

Bremerhaven, 9 July 2013. Yesterday (8 July 2013) a huge area of the ice shelf broke away from the Pine Island glacier, the longest and fastest flowing glacier in the Antarctic, and is now floating in the Amundsen Sea in the form of a very large iceberg. Scientists of the Alfred Wegener Institute for Polar and Marine Research in the Helmholtz Association have been following this natural spectacle via the earth observation satellites TerraSAR-X from the German Space Agency (DLR) and have documented it in many individual images. The data is intended to help solve the physical puzzle of this “calving“.

Scientists from the American space agency NASA discovered the first crack in the glacier tongue on 14 October 2011 when flying over the area. At that time it was some 24 kilometres long and 50 metres wide. ”As a result of these cracks, one giant iceberg broke away from the glacier tongue. It measures 720 square kilometres and is therefore almost as large as the city of Hamburg“, reports Prof. Angelika Humbert, ice researcher at the Alfred Wegener Institute. 

The glaciologist and her team used the high resolution radar images of the DLR earth observation satellite TerraSAR-X to observe the progress of the two cracks and to better understand the physical processes behind the glacier movements. The researchers were thus able to measure the widths of the gaps and calculate the flow speed of the ice. ”Above the large crack, the glacier last flowed at a speed of twelve metres per day“, reports Humbert’s colleague Dr. Dana Floricioiu from DLR. And Nina Wilkens, PhD graduate in Prof. Humbert’s team, adds: “Using the images we have been able to follow how the larger crack on the Pine Island glacier extended initially to a length of 28 kilometres. Shortly before the “birth” of the iceberg, the gap then widened bit by bit so that it measured around 540 metres at its widest point.“

The scientists incorporate these and other TerraSAR-X satellite data in computer simulations using which they are able to model the break and flow mechanisms of the ice masses. “Glaciers are constantly in motion. They have their very own flow dynamics. Their ice is exposed to permanent tensions and the calving of icebergs is still largely unresearched “, explains ice modeller Angelika Humbert. 

The scientist and her team then compare their simulation results with current satellite data such as from TerraSAR-X. If the model agrees with reality, the scientists can conclude, for example, the gliding property of the ground beneath the glacier ice and how the ice flow could behave in the event of further global warming. 

Are ice breaks caused by climate change? Angelika Humbert does not so far see any direct connection: “The creation of cracks in the shelf ice and the development of new icebergs are natural processes“, says the glaciologist. However, the Pine Island glacier, which flows from the Hudson mountains to the Amundsen Sea, was the fastest flowing glacier in the Western Antarctic with a flow speed of around 4 kilometres per year. This speed is less caused by the rising air temperatures, however, and is more attributable to the fact that the wind directions in the Amundsen Sea have altered. ”The wind now brings warm sea water beneath the shelf ice. Over time, this process means that the shelf ice melts from below, primarily at the so-called grounding line, the critical transition to the land ice“, says the scientist. 

For the Western Antarctic ice shelf, an even faster flow of the Pine Island glacier would presumably have serious consequences. “The Western Antarctic land ice is on land which is deeper than sea level. Its “bed” tends towards the land. The danger therefore exists that these large ice masses will become unstable and will start to slide“, says Angelika Humbert. If the entire West Antarctic ice shield were to flow into the Ocean, this would lead to a global rise in sea level of around 3.3 metres. 

Info box: Shelf ice 

The shelf ice, which is 200 to 1200 metres, thick is created by glaciers sliding into the sea. It is therefore an extension of the Antarctic land ice which thins at the edges and floats on the sea. The ice shelf itself rests on the Antarctic continent, reaching a thickness of up to four kilometres and is largely frozen to the rock bottom. A special feature of the Western Antarctic is that large areas of land are below sea level. (AWI press release, july 9,2013)

Miscellanea Artico : News feature: 2013-197

June 10, 2013 Is a Sleeping Climate Giant Stirring in the Arctic? Flying low and slow above the wild, pristine terrain of Alaska's North Slope in a specially instrumented NASA plane, research scientist Charles Miller of NASA's Jet Propulsion Laboratory, Pasadena, Calif., surveys the endless whiteness of tundra and frozen permafrost below. On the horizon, a long, dark line appears. The plane draws nearer, and the mysterious object reveals itself to be a massive herd of migrating caribou, stretching for miles. It's a sight Miller won't soon forget. "Seeing those car  ibou marching single-file across the tundra puts what we're doing here in the Arctic into perspective," said Miller, principal investigator of the Carbon in Arctic Reservoirs Vulnerability Experiment (CARVE), a five-year NASA-led field campaign studying how climate change is affecting the Arctic's carbon cycle. "The Arctic is critical to understanding global climate," he said. "Climate change is already happening in the Arctic, faster than its ecosystems can adapt. Looking at the Arctic is like looking at the canary in the coal mine for the entire Earth system." Aboard the NASA C-23 Sherpa aircraft from NASA's Wallops Flight Facility, Wallops Island, Va., Miller, CARVE Project Manager Steve Dinardo of JPL and the CARVE science team are probing deep into the frozen lands above the Arctic Circle. The team is measuring emissions of the greenhouse gases carbon dioxide and methane from thawing permafrost -- signals that may hold a key to Earth's climate future. What Lies Beneath Permafrost (perennially frozen) soils underlie much of the Arctic. Each summer, the top layers of these soils thaw. The thawed layer varies in depth from about 4 inches (10 centimeters) in the coldest tundra regions to several yards, or meters, in the southern boreal forests. This active soil layer at the surface provides the precarious foothold on which Arctic vegetation survives. The Arctic's extremely cold, wet conditions prevent dead plants and animals from decomposing, so each year another layer gets added to the reservoirs of organic carbon sequestered just beneath the topsoil. Over hundreds of millennia, Arctic permafrost soils have accumulated vast stores of organic carbon - an estimated 1,400 to 1,850 petagrams of it (a petagram is 2.2 trillion pounds, or 1 billion metric tons). That's about half of all the estimated organic carbon stored in Earth's soils. In comparison, about 350 petagrams of carbon have been emitted from all fossil-fuel combustion and human activities since 1850. Most of this carbon is located in thaw-vulnerable topsoils within 10 feet (3 meters) of the surface. But, as scientists are learning, permafrost - and its stored carbon - may not be as permanent as its name implies. And that has them concerned. "Permafrost soils are warming even faster than Arctic air temperatures - as much as 2.7 to 4.5 degrees Fahrenheit (1.5 to 2.5 degrees Celsius) in just the past 30 years," Miller said. "As heat from Earth's surface penetrates into permafrost, it threatens to mobilize these organic carbon reservoirs and release them into the atmosphere as carbon dioxide and methane, upsetting the Arctic's carbon balance and greatly exacerbating global warming." Current climate models do not adequately account for the impact of climate change on permafrost and how its degradation may affect regional and global climate. Scientists want to know how much permafrost carbon may be vulnerable to release as Earth's climate warms, and how fast it may be released. CARVing Out a Better Understanding of Arctic Carbon Enter CARVE. Now in its third year, this NASA Earth Ventures program investigation is expanding our understanding of how the Arctic's water and carbon cycles are linked to climate, as well as what effects fires and thawing permafrost are having on Arctic carbon emissions. CARVE is testing hypotheses that Arctic carbon reservoirs are vulnerable to climate warming, while delivering the first direct measurements and detailed regional maps of Arctic carbon dioxide and methane sources and demonstrating new remote sensing and modeling capabilities. About two dozen scientists from 12 institutions are participating. "The Arctic is warming dramatically - two to three times faster than mid-latitude regions - yet we lack sustained observations and accurate climate models to know with confidence how the balance of carbon among living things will respond to climate change and related phenomena in the 21st century," said Miller. "Changes in climate may trigger transformations that are simply not reversible within our lifetimes, potentially causing rapid changes in the Earth system that will require adaptations by people and ecosystems." The CARVE team flew test flights in 2011 and science flights in 2012. This April and May, they completed the first two of seven planned monthly campaigns in 2013, and they are currently flying their June campaign. Each two-week flight campaign across the Alaskan Arctic is designed to capture seasonal variations in the Arctic carbon cycle: spring thaw in April/May, the peak of the summer growing season in June/July, and the annual fall refreeze and first snow in September/October. From a base in Fairbanks, Alaska, the C-23 flies up to eight hours a day to sites on Alaska's North Slope, interior and Yukon River Valley over tundra, permafrost, boreal forests, peatlands and wetlands. The C-23 won't win any beauty contests - its pilots refer to it as "a UPS truck with a bad nose job." Inside, it's extremely noisy - the pilots and crew wear noise-cancelling headphones to communicate. "When you take the headphones off, it's like being at a NASCAR race," Miller quipped. But what the C-23 lacks in beauty and quiet, it makes up for in reliability and its ability to fly "down in the mud," so to speak. Most of the time, it flies about 500 feet (152 meters) above ground level, with periodic ascents to higher altitudes to collect background data. Most airborne missions measuring atmospheric carbon dioxide and methane do not fly as low. "CARVE shows you need to fly very close to the surface in the Arctic to capture the interesting exchanges of carbon taking place between Earth's surface and atmosphere," Miller said. Onboard the plane, sophisticated instruments "sniff" the atmosphere for greenhouse gases. They include a very sensitive spectrometer that analyzes sunlight reflected from Earth's surface to measure atmospheric carbon dioxide, methane and carbon monoxide. This instrument is an airborne simulator for NASA's Orbiting Carbon Observatory-2 (OCO-2) mission to be launched in 2014. Other instruments analyze air samples from outside the plane for the same chemicals. Aircraft navigation data and basic weather data are also collected. Initial data are delivered to scientists within 12 hours. Air samples are shipped to the University of Colorado's Institute for Arctic and Alpine Research Stable Isotope Laboratory and Radiocarbon Laboratory in Boulder for analyses to determine the carbon's sources and whether it came from thawing permafrost. Much of CARVE's science will come from flying at least three years, Miller says. "We are showing the power of using dependable, low-cost prop planes to make frequent, repeat measurements over time to look for changes from month to month and year to year." Ground observations complement the aircraft data and are used to calibrate and validate them. The ground sites serve as anchor points for CARVE's flight tracks. Ground data include air samples from tall towers and measurements of soil moisture and temperature to determine whether soil is frozen, thawed or flooded. A Tale of Two Greenhouse Gases It's important to accurately characterize the soils and state of the land surfaces. There's a strong correlation between soil characteristics and release of carbon dioxide and methane. Historically, the cold, wet soils of Arctic ecosystems have stored more carbon than they have released. If climate change causes the Arctic to get warmer and drier, scientists expect most of the carbon to be released as carbon dioxide. If it gets warmer and wetter, most will be in the form of methane. The distinction is critical. Molecule per molecule, methane is 22 times more potent as a greenhouse gas than carbon dioxide on a 100-year timescale, and 105 times more potent on a 20-year timescale. If just one percent of the permafrost carbon released over a short time period is methane, it will have the same greenhouse impact as the 99 percent that is released as carbon dioxide. Characterizing this methane to carbon dioxide ratio is a major CARVE objective. There are other correlations between Arctic soil characteristics and the release of carbon dioxide and methane. Variations in the timing of spring thaw and the length of the growing season have a major impact on vegetation productivity and whether high northern latitude regions generate or store carbon. CARVE is also studying wildfire impacts on the Arctic's carbon cycle. Fires in boreal forests or tundra accelerate the thawing of permafrost and carbon release. Detailed fire observation records since 1942 show the average annual number of Alaska wildfires has increased, and fires with burn areas larger than 100,000 acres are occurring more frequently, trends scientists expect to accelerate in a warming Arctic. CARVE's simultaneous measurements of greenhouse gases will help quantify how much carbon is released to the atmosphere from fires in Alaska - a crucial and uncertain element of its carbon budget. Early Results The CARVE science team is busy analyzing data from its first full year of science flights. What they're finding, Miller said, is both amazing and potentially troubling. "Some of the methane and carbon dioxide concentrations we've measured have been large, and we're seeing very different patterns from what models suggest," Miller said. "We saw large, regional-scale episodic bursts of higher-than-normal carbon dioxide and methane in interior Alaska and across the North Slope during the spring thaw, and they lasted until after the fall refreeze. To cite another example, in July 2012 we saw methane levels over swamps in the Innoko Wilderness that were 650 parts per billion higher than normal background levels. That's similar to what you might find in a large city." Ultimately, the scientists hope their observations will indicate whether an irreversible permafrost tipping point may be near at hand. While scientists don't yet believe the Arctic has reached that tipping point, no one knows for sure. "We hope CARVE may be able to find that 'smoking gun,' if one exists," Miller said. Other institutions participating in CARVE include City College of New York; the joint University of Colorado/National Oceanic and Atmospheric Administration's Cooperative Institute for Research in Environmental Sciences, Boulder, Colo.; San Diego State University; University of California, Irvine; California Institute of Technology, Pasadena; Harvard University, Cambridge, Mass.; University of California, Berkeley; Lawrence Berkeley National Laboratory, Berkeley, Calif.; University of California, Santa Barbara; NOAA's Earth System Research Laboratory, Boulder, Colo.; and University of Melbourne, Victoria, Australia. NASA NEWS -

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Russia: Evacuation of Polar researches to start this week

 The Russian Government pays 65 million rubles to bring the crew of the floating research station “North Pole-40” safely back to land.

By

Trude Pettersen

May 27, 2013

Russia’s Prime Minister Dmitry Medvedev has approved the plans for evacuation of 16 persons and large amounts of materials from the floating research station “North Pole-40”, drifting close to the North Pole. As BarentsObserverreported, the ice floe carrying the station has started to break up and the scientists and equipment need to evacuated before long.

The nuclear-powered icebreaker “Yamal” is now preparing to leave for the Arctic Ocean on a rescue mission. The vessel is planned to leave Murmansk by the end of this week and will reach the station approximately two weeks later. The rescue mission is estimated to cost 65 million rubles (app €1.6 million).

The ice floe has now broken up in pieces that are 100 times 150 meters large, Head of the Federal Service for Hydrometeorology and Environmental Monitoring Aleksander Frolov says to Rossiyskaya Gazeta. The piece the research station is located on is about 2.5 meters thick. The air temperature in the area is -10 and rising.

The crew cannot be rescued by plane or helicopter, Frolov says. Because of ice ridging on the floe, it is not possible to build an airstrip for any plane, and the floe has drifted out of reach for helicopters.

The scientific station “North Pole-40” will continue its work in the Arctic even after it has been removed from the ice floe. An abandoned Polar station in Mys Baranova on Severnaya Zemlya is now being prepared to house the researchers and their equipment.

Russia has had floating research stations in the Arctic since 1937, when the first scientific drifting ice station in the world – “North Pole-1”, was established. From 1954 Soviet "North Pole" stations worked continuously, with one to three such stations operating simultaneously every year. In the post-Soviet era, Russian exploration of the Arctic by drifting ice stations was suspended for twelve years, and was resumed in 2003. (Barents Observer)

Seal of quality on the anniversary

(a cura di Alberto Marenga)

Osservazioni satellitari per il buco dell'Ozono

Satellites show that the recent ozone hole over Antarctica was the smallest seen in the past decade. Long-term observations also reveal that Earth’s ozone has been strengthening following international agreements to protect this vital layer of the atmosphere.

According to the ozone sensor on Europe’s MetOp weather satellite, the hole over Antarctica in 2012 was the smallest in the last 10 years.

The instrument continues the long-term monitoring of atmospheric ozone started by its predecessors on the ERS-2 and Envisat satellites.

Since the beginning of the 1980s, an ozone hole has developed over Antarctica during the southern spring – September to November – resulting in a decrease in ozone concentration of up to 70%.

Ozone depletion is more extreme in Antarctica than at the North Pole because high wind speeds cause a fast-rotating vortex of cold air, leading to extremely low temperatures.

Under these conditions, human-made chlorofluorocarbons – CFCs – have a stronger effect on the ozone, depleting it and creating the infamous hole.

Over the Arctic, the effect is far less pronounced because the northern hemisphere’s irregular landmasses and mountains normally prevent the build-up of strong circumpolar winds.

Reduced ozone over the southern hemisphere means that people living there are more exposed to cancer-causing ultraviolet radiation.

International agreements on protecting the ozone layer – particularly the Montreal Protocol – have stopped the increase of CFC concentrations, and a drastic fall has been observed since the mid-1990s.

However, the long lifetimes of CFCs in the atmosphere mean it may take until the middle of this century for the stratosphere’s chlorine content to go back to values like those of the 1960s.

The evolution of the ozone layer is affected by the interplay between atmospheric chemistry and dynamics like wind and temperature.

If weather and atmospheric conditions show unusual behaviour, it can result in extreme ozone conditions – such as the record low observed in spring 2011 in the Arctic – or last year’s unusually small Antarctic ozone 

Ancient microbes found in Antarctic lake

Nearly 65 feet beneath the icy surface of a remote Antarctic lake, scientists from NASA, the Desert Research Institute (DRI) in Reno, Nev., the University of Illinois at Chicago, and nine other institutions, have uncovered a community of bacteria existing in one of Earth's darkest, saltiest and coldest habitats.

Lake Vida, the largest of several unique lakes found in the McMurdo Dry Valleys, contains no oxygen, is mostly frozen and possesses the highest nitrous oxide levels of any natural water body on Earth. A briny liquid, which is approximately six times saltier than seawater, percolates throughout the icy environment where the average temperature is minus 8 degrees Fahrenheit. The international team of scientists published their findings online Nov. 26, in the Proceedings of the National Academy of Sciences Early Edition.

"This study provides a window into one of the most unique ecosystems on Earth," said Alison Murray, a molecular microbial ecologist and polar researcher at the DRI and the report's lead author. "Our knowledge of geochemical and microbial processes in lightless icy environments, especially at subzero temperatures, has been mostly unknown up until now. This work expands our understanding of the types of life that can survive in these isolated, cryoecosystems and how different strategies may be used to exist in such challenging environments."

Despite the very cold, dark and isolated nature of the habitat, the report finds the brine harbors a surprisingly diverse and abundant variety of bacteria that survive without a current source of energy from the sun. Previous studies of Lake Vida dating back to 1996 indicate the brine and its inhabitants have been isolated from outside influences for more than 3,000 years.

"This system is probably the best analog we have for possible ecosystems in the subsurface waters of Saturn's moon Enceladus and Jupiter's moon Europa," said Chris McKay, a senior scientist and co-author of the paper at NASA's Ames Research Center, Moffett Field, Calif.

Murray and her co-authors and collaborators, including Peter Doran, the project's principal investigator at the University of Illinois at Chicago, developed stringent protocols and specialized equipment for their 2005 and 2010 field campaigns to sample from the lake brine while avoiding contaminating the pristine ecosystem.

"The microbial ecosystem discovered at Lake Vida expands our knowledge of environmental limits for life and helps define new niches of habitability," said Adrian Ponce, co-author from NASA's Jet Propulsion Laboratory, Pasadena, Calif., who enumerated viable bacterial spore populations extracted from Lake Vida.

To sample unique environments such as this, researchers must work under secure, sterile tents on the lake's surface. The tents kept the site and equipment clean as researchers drilled ice cores, collected samples of the salty brine residing in the lake ice and assessed the chemical qualities of the water and its potential for harboring and sustaining life.

Geochemical analyses suggest chemical reactions between the brine and the underlying iron-rich sediments generate nitrous oxide and molecular hydrogen. The latter, in part, may provide the energy needed to support the brine's diverse microbial life.

Additional research is under way to analyze the abiotic, chemical interactions between the Lake Vida brine and its sediment, in addition to investigating the microbial community by using different genome sequencing approaches. The results could help explain the potential for life in other salty, cryogenic environments beyond Earth, such as purported subsurface aquifers on Mars.

(NASA news, nov.30,2012)

Amplified Grenhouse Effect Schifta North's Growing Seasoms

Amplified Greenhouse Effect Shifts North's Growing Seasons

March 10, 2013: Vegetation growth at Earth's northern latitudes increasingly resembles lusher latitudes to the south, according to a NASA-funded study based on a 30-year record of ground-based and satellite data sets.
In a paper published Sunday, March 10, in the journal Nature Climate Change, an international team of university and NASA scientists examined the relationship between changes in surface temperature and vegetation growth from 45 degrees north latitude to the Arctic Ocean. Results show temperature and vegetation growth at northern latitudes now resemble those found 4 degrees to 6 degrees of latitude farther south as recently as 1982.
"Higher northern latitudes are getting warmer, Arctic sea ice and the duration of snow cover are diminishing, the growing season is getting longer and plants are growing more," said Ranga Myneni of Boston University's Department of Earth and Environment. "In the north's Arctic and boreal areas, the characteristics of the seasons are changing, leading to great disruptions for plants and related ecosystems."

Of the 10 million square miles (26 million square kilometers) of northern vegetated lands, 34 to 41 percent showed increases in plant growth (green and blue), 3 to 5 percent showed decreases in plant growth (orange and red), and 51 to 62 percent showed no changes (yellow) over the past 30 years. Satellite data in this visualization are from AVHRR and MODIS. Credit: NASA's Goddard Space Flight Center Scientific Visualization Studio Myneni and colleagues used satellite data to quantify vegetation changes at different latitudes from 1982 to 2011. Data used in this study came from NOAA's Advanced Very High Resolution Radiometers (AVHRR) onboard a series of polar-orbiting satellites and NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) instruments on the Terra and Aqua satellites.
As a result of enhanced warming and a longer growing season, large patches of vigorously productive vegetation now span a third of the northern landscape, or more than 3.5 million square miles (9 million square kilometers). That is an area about equal to the contiguous United States. This landscape resembles what was found 250 to 430 miles (400 to 700 kilometers) to the south in 1982.

"It's like Winnipeg, Manitoba, moving to Minneapolis-Saint Paul in only 30 years," said co-author Compton Tucker of NASA's Goddard Space Flight Center in Greenbelt, Md.

The Arctic's greenness is visible on the ground as an increasing abundance of tall shrubs and trees in locations all over the circumpolar Arctic. Greening in the adjacent boreal areas is more pronounced in Eurasia than in North America.
An amplified greenhouse effect is driving the changes, according to Myneni. Increased concentrations of heat-trapping gasses, such as water vapor, carbon dioxide and methane, cause Earth's surface, ocean and lower atmosphere to warm. Warming reduces the extent of polar sea ice and snow cover, and, in turn, the darker ocean and land surfaces absorb more solar energy, thus further heating the air above them.
"This sets in motion a cycle of positive reinforcement between warming and loss of sea ice and snow cover, which we call the amplified greenhouse effect," Myneni said. "The greenhouse effect could be further amplified in the future as soils in the north thaw, releasing potentially significant amounts of carbon dioxide and methane."

To find out what is in store for future decades, the team analyzed 17 climate models. These models show that increased temperatures in Arctic and boreal regions would be the equivalent of a 20-degree latitude shift by the end of this century relative to a period of comparison from 1951-1980. However, researchers note that plant growth in the north may not continue on its current trajectory. The ramifications of an amplified greenhouse effect, such as frequent forest fires, outbreak of pest infestations and summertime droughts, may slow plant growth. Also, warmer temperatures alone in the boreal zone do not guarantee more plant growth, which also depends on the availability of water and sunlight.
"Satellite data identify areas in the boreal zone that are warmer and dryer and other areas that are warmer and wetter," said co-author Ramakrishna Nemani of NASA's Ames Research Center in Moffett Field, Calif. "Only the warmer and wetter areas support more growth."
"We found more plant growth in the boreal zone from 1982 to 1992 than from 1992 to 2011, because water limitations were encountered in the later two decades of our study," said co-author Sangram Ganguly of the Bay Area Environmental Research Institute and NASA Ames.
Data, results and computer codes from this study will be made available on NASA Earth Exchange (NEX), a collaborative supercomputing facility at Ames Research Center, Moffett Field, Calif. NEX is designed to bring scientists together with data, models and computing resources to accelerate research and innovation and provide transparency. (NASA Science march 10,2013)

Antarctic and Artic Insects Use Different Genetic Mechanisms to Cope With LAck of Water

Genomic techniques facilitate discovery that gene expression causes disparity

March 11, 2013

Although they live in similarly extreme ecosystems at opposite ends of the world, Antarctic insects appear to employ entirely different methods at the genetic level to cope with extremely dry conditions than their counterparts that live north of the Arctic Circle, according to National Science Foundation- (NSF) funded researchers.

Writing in the Proceedings of the National Academy of Sciences, the researchers concluded, "Polar arthropods have developed distinct... mechanisms to cope with similar desiccating conditions."

The researchers noted that aside from the significance of the specific discovery about the genetics of how creatures cope in polar environments, the new finding is important because it shows how relatively new and developing scientific techniques, including genomics, are opening new scientific vistas in the Polar Regions, which were once thought to be relatively uniform and, relatively speaking, scientifically sterile environments.

"It's great to have an Antarctic animal that has entered the genomic era," said David Denlinger, a distinguished professor of entomology at Ohio State University and a co-author of the paper. "This paper, which analyzed the expression of thousands of genes in response to the desiccating environment of Antarctica, is just one example of the power that the genomic revolution offers for advancing polar science. "

The collaborative research--which included contributions from scientists at Ohio State University, the Centre National de la Recherche Scientifique (National Center for Scientific Research) in France, Catholic University of Louvain in Belgium, Stanford University, and Miami University in Ohio--was supported in part by the Division of Polar Programs in NSF's Geosciences Directorate.

Polar Programs manages the U.S. Antarctic Program, through which it coordinates all U.S. research on the southernmost continent and aboard ships in the Southern Ocean as well as providing the necessary logistical support.

The finding also adds to the developing picture of the Polar Regions as having similarities and yet subtle and perhaps very important differences, previously undetected by science. NSF-funded scientists late last year, for example, published researchindicating that differing contributions of freshwater from glaciers and streams to the Arctic and Southern oceans may be responsible for the fact that the majority of microbial communities that thrive near the surface of the Polar oceans share few common members.

Although Antarctica's surrounding oceans and coastal margins are home to a variety of large creatures such as seals, penguins and whales, insect life is rare, except on the Antarctic Peninsula.

There, the Antarctic midge, Belgica antarctica, occupies its unique ecological niche.

The research team that produced the new findings collected specimens for their research from offshore islands near NSF's Palmer Station on Anvers Island in the Peninsula region.

Surrounded by an ocean, the Antarctic continent is a polar desert where creatures have adapted to life with infrequent access to liquid water. The researchers note that Antarctic midge larvae, for example, "are remarkably tolerant of dehydration, surviving losses of up to 70 percent of their body water."

They also note that, in general, "insects, in particular, are at high risk of dehydration because of their small body size and consequent high surface-area-to-volume ratio."

Among Antarctic insects, the ability to tolerate dehydration is an important evolutionary development, allowing the creatures to successful survive the cold and dry southern winter.

"The loss of water enhances acute freezing tolerance," they write. "In addition, overwintering midge larvae are capable of undergoing another distinct form of dehydration, known as cryoprotective dehydration.

Cryoprotective dehydration is a mechanism in which a gradual decrease in temperature in the presence of environmental ice "creates a vapor pressure gradient that draws water out of the body, thereby depressing the body fluid melting point and allowing larvae to remain unfrozen at subzero temperatures."

The researchers compared the midge's strategy to those of other terrestrial arthropods that cope with prolonged periods when water is lacking, including the Arctic springtailMegaphorura arctica and Folsomia candida, which are more widely distributed across the globe; both species are members of a group of arthropods, which are closely related to insects, known as Collembola.

The differences, they concluded, lie in the way that various genes express themselves.

After a detailed analysis of gene expression in the various species, the researchers concluded that "although B. antarcticaand M. arctica are adapted to similar environments, our analysis indicated very little overlap in expression profiles between these two arthropods."

They add that "these differences in expression patterns may reflect different strategies for combating dehydration; whereasB. antarctica shuts down metabolic activity and waits for favorable conditions to return, F. candida [instead] relies on active water-vapor absorption to restore water balance during prolonged periods of desiccation."

They further add that because of the taxonomic difference between the Antarctic midge and the collembolan species with which gene expression was compared, more work is needed "to better understand the evolutionary physiology of dehydration tolerance in this taxonomic family."

(NSF,march 11,2013)

Clearest evidence yet of polar ice losses

After two decades of satellite observations, an international team of experts brought together by ESA and NASA has produced the most accurate assessment of ice losses from Antarctica and Greenland to date. This study finds that the combined rate of ice sheet melting is increasing.
The new research shows that melting of the Antarctic and Greenland ice sheets has added 11.1 mm to global sea levels since 1992.

 This amounts to about 20% of all sea-level rise over the survey period.

About two thirds of the ice loss was from Greenland, and the remainder was from Antarctica.Although the ice sheet losses fall within the range reported by the Intergovernmental Panel on Climate Change in 2007, the spread of the estimate at that time was so broad that it was not clear whether Antarctica was growing or shrinking.

The new estimates are a vast improvement – more than twice as accurate – thanks to the inclusion of more satellite data, and confirm that both Antarctica and Greenland are losing ice.

The study also shows that the combined rate of ice sheet melting has increased over time and, altogether, Greenland and Antarctica are now losing more than three times as much ice, equivalent to 0.95 mm of sea-level rise per year, as they were in the 1990s, equivalent to 0.27 mm of sea level rise per year.  

The 47 experts combined observations from 10 different satellite missions to reconcile the differences between dozens of earlier ice sheet studies and produce the first consistent measurement of polar ice sheet changes. Earth observation satellites are key to monitoring the polar ice because they carry instruments that measure changes in the thickness of the ice sheets, fluctuations in the speed of the outlet glaciers and even small changes in Earth’s gravity field caused by melting ice.

As outlined in the paper ‘A Reconciled Estimate of Ice Sheet Mass Balance’ published today in Science, the researchers carefully matched time periods and survey areas, and combined measurements from European, Canadian, American and Japanese satellites. The measurement were acquired by instruments such as the radar altimeters and synthetic aperture radars flown on ESA’s ERS-1, ERS-2 and Envisat missions from 1991.

“The success of this venture is due to the cooperation of the international scientific community, and to the provision of precise satellite sensors by our space agencies,” said Professor Andrew Shepherd from the University of Leeds and one of the leaders of the study.“Without these efforts, we would not be in a position to tell people with confidence how Earth’s ice sheets have changed, and to end the uncertainty that has existed for many years.” The study also found variations in the pace of Ice sheet in Antarctica and Greenland.

“The rate of ice loss from Greenland has increased almost five-fold since the mid-1990s.

“In contrast, while the regional changes in Antarctic ice over time are sometimes quite striking, the overall balance has remained fairly constant – at least within the certainty of the satellite measurements we have to hand,” said co-leader of the study Dr Erik Ivins from NASA’s Jet Propulsion Laboratory.

The Ice Sheet Mass Balance Inter-comparison Exercise is a collaboration between 47 researchers from 26 laboratories, supported by ESA and NASA.

Europe’s Global Monitoring for Environment and Security programme will continue to monitor changes in the polar ice sheets during the coming decades, with the SAR and radar altimeter sensors on the Sentinel-1 and Sentinel-3 satellite series, scheduled to be launched from 2013 onwards.
 (ESA news, nov. 30,2012)
 

Novoportovskoye will boost Arctic oil shipping

The biggest oil field in the Yamal Peninsula will be ready for production in 2015. Most of the oil will be shipped out along the Northern Sea Route.

By

Atle Staalesen

February 13, 2013

The Novoportovskoye field holds 220 million tons of extractable oil and 260 billion cubic meters of gas and is under development by the Gazprom Neft company. The nearby terminal at Cape Kamenny in the Ob Bay is to be ready already in 2014, while field production launch is scheduled for 2015.

When ready, the Novoportovskoye field will result in a major increase in the level of oil shipments in Russian Arctic waters. All the oil is to be shipped out along the Northern Sea Route with the help of icebreakers. In addition, a new gas pipeline is to connect the field with Gazprom's pipe infrastructure in the region.

The field is located about 30 km inland from the Ob Bay, near the town of Novy Port. A public hearing on the project is currently underway in the town, Biztass.ru reports.

Gazprom Neft will in 2013 drill another three wells at the field. In 2012, a total of five wells were drilled, Oilru.com reports.

As previously reported, Gazprom Neft’s planned terminal at Cape Kammeny is located about 400 km south of the Sabetta Port, the site where Novatek is planning its Yamal LNG plant together with French energy major Total. A test sailing mission with the nuclear-powered icebreaker “Vaigach” in late 2011 showed that the site can be used for the purpose. The Ob waters are in winter covered by ice with a thickness of up to two meters and the ice-free season lasts only about three months.

Cryosat reveals major loss of Arctric sea ice

An international team of scientists using new measurements from ESA’s ice mission has discovered that the volume of Arctic sea ice has declined by 36% during autumn and 9% during winter between 2003 and 2012.
Satellite records show a constant downward trend in the area covered by Arctic sea ice during all seasons, but in particular in summer. The past six years have seen the lowest summer ice extent in three decades, eaching the lowest last September at about 3.61 million sq km.
A team of scientists led by University College London has now generated estimates of the sea-ice volume for the 2010–11 and 2011–12 winters over the Arctic basin using data from ESA’s CryoSat satellite.
This study has confirmed, for the first time, that the decline in sea ice coverage in the polar region has been accompanied by a substantial decline in ice volume.
The new CryoSat dataset shows the volume’s continuing decline observed from 2003 to 2008 by NASA’s ICESat satellite.
Since 2008, the Arctic has lost about 4300 cubic km of ice during the autumn period and about 1500 cubic km in winter.
The team confirmed CryoSat estimates using independent ground and airborne measurements carried out by ESA and international scientists during the last two years in the polar region, as well as by comparing measurements from NASA’s Operation IceBridge.
“The data reveal that thick sea ice has disappeared from a region to the north of Greenland, the Canadian Archipelago and to the northeast of Svalbard,” said Katharine Giles, co-author of the study‘CryoSat-2 estimates of Arctic sea ice thickness and volume’, recently published online in Geophysical Research Letters.
“Other satellites have already shown drops in the area covered by Arctic sea ice as the climate has warmed, but CryoSat allows scientists to estimate the volume of sea ice – a much more accurate indicator of the changes taking place in the Arctic,” added Tommaso Parrinello, CryoSat Mission Manager.
To do this, CryoSat’s high-resolution radar altimeter sends pulses of microwave energy down towards the ice.
The energy bounces off both the top sections of ice and the water in the cracks between. The difference in height between these two surfaces allows scientists to calculate the ‘freeboard’ – the height of ice above the water – and, as a result, volume of the ice cover.
While the researchers say two years of CryoSat data aren’t indicative of a long-term change, they speculate that the lower ice thickness and volume in the winter of 2012, compared to the winter of 2011, may have contributed to the record minimum ice extent during the 2012 autumn.
The findings are the result of an international collaboration between teams from University College London (UCL), ESA, the Jet Propulsion Laboratory, the University of Washington, York University, Alfred Wegener Institute for Polar and Marine Research, Woods Hole Oceanographic Institution, Morgan State University and the University of Maryland
The research was funded by the Natural Environment Research Council, ESA, the DLR German Aerospace Center, Alberta Ingenuity, the National Science Foundation, NASA and Office of Naval Research.
The lead author of this study was Professor Seymour Laxon, who passed away in early January.
Prof. Laxon was the Director of the Centre for Polar Observation and Modelling at UCL and a Principal Scientist for several ESA missions. He was part of the UCL team that proposed CryoSat to ESA in 1999, and was a key figure during the development and operational phases of the mission.
This was his first eagerly anticipated published work on CryoSat-derived sea ice record.
(ESA news, feb 3,2013)

Antartide. Temperature Mensili Dicembre 2012

Monthly Climate Summary for December 2012

South Pole Station, Antarctica

 Temperature:

Average temp............ -25.3°C / -13.5°F

 Departure from normal...  +2.5°C /  +4.5°F

 Maximum temp............ -21.1°C /  -6.0°F on day 25

Minimum temp............ -29.8°C / -21.6°F on days 01 and 17

Wind:

Average wind speed.......... 8.9 mph or 7.7 knots

 Prevailing wind direction... Grid Northeast or 030 degrees

Maximum wind speed.......... 28 mph or 24 knots on days 03 and 21

Maximum wind direction...... Grid Northeast

Average vectored wind....... 043 degrees at 5.3 knots

Station Pressure:

Average pressure........ 690.0 mb or 20.376 in. Hg

Departure from normal...  +1.9 mb or +0.056 in. Hg

Highest pressure........ 701.5 mb or 20.715 in. Hg on day 26

Lowest pressure......... 684.5 mb or 20.213 in. Hg on days 01, 02, and 17

Physio-altitude:

Average Physio-alt = 10253 ft / 3125 m

Highest Physio-alt = 10459 ft / 3188 m on days 01, 02, and 17

 Lowest Physio-alt  =  9827 ft / 2995 m on day 26

Sky Cover:

Average cloud cover (8ths)... 04

Days clear................... 07

Days partly cloudy........... 18

Days cloudy.................. 06

Sunshine:

Sunset on 23 March 2013

Average hours per day... 18.6

Percent of possible..... 78

Visibility... 1 day with a visibility of 1/4 mile or less.

Snowfall..... Trace; average net change at snow stakes +0.385 inches.

Balloon flight data:

Number of soundings for the month... 62

Average height of sounding.......... 26.8 mb or 25265 meters above msl

Highest sounding.................... 10.2 mb or 31848 meters above msl

                                     on the day 28 /00Z sounding

 Remarks:

00 soundings were missed.

61 soundings were terminated above 50 mb.

01 soundings were terminated between 50 and 100 mb.

00 soundings were terminated below 100 mb.

**RECORDS**

December 7th: The average daily wind speed of 2.8 kts/3.3 mph broke the previous lowest average daily wind speed record of 3.6 kts/4.1 mph set in 1997.

Prepared by: Timothy Markle/ Phillip Marzette/ Jeremiah Jolliff

Meteorology Department

Amundsen-Scott South Pole Station, Antarctica

720-568-1810 (satellite dependent)

720-568-1809 (satellite dependent)

X61810, X61809 (on-station)

Pol-Met@usap.gov

 (a cura di Alberto Marenga)

Alberto Marenga. Collaborazione

E' stata attivata un a collaborazione tra il blog e il Dott. Alberto Marenga volta a pubblicare i dati meteorologici mensili al Polo Sud.

Ricerche dell'ENI in Artide

L’Eni, Ente Nazionale Idrocarburi  Italiano, ha firmato a mosca un protocollo di intesa ed accordo per la valorizzazione congiunta dei giacimenti di gas e petrolio nel Mare di Barents, nell’Artico e nel Mar Nero con la Rosneft, prima società russa di produzione di petrolio.

L’accordo è stato firmato il 25 aprile 2012 a Mosca dagli amministratori delegati  delle due società, Paolo Scaroni e Eduard Khudainatov alla presenta di Putin, e  dell’Ambasciatore italiano in Russia, Antonio Zanardi Landi.

La Rosneft aveva la scorsa settimana firmato un accordo con la società statunitense Exxnmobil, in relazione allo sfruttamento di alcuni giacimenti di petroolio in Artide.

L’accordo, tra l’altro, prevede lo sviluppo congiunto di licenze esplorative situate offshore russo del Mare di barents e nel mar Nero., lo scambio di tecnologie e personale e l’acquisizione da parte di Rosneft di partecipazioni Eni a progetti internazionali.

Le sue società costituiranno tre joint venture partecipate da Eni con una quota di 33, 33 per cento per lo sviluppo congiunto delle licenze Fedynsky, e Tsentralmo-Barentsevsky situati nell’offshore russo del mare di Barents  e Zapadno-Cernomorsky, nell’offshore russo del mar nero. In ogni caso la società Rosneft rimarrà titolare delle licenze.

I PIU'  SINCERI

 AUGURI

 DI UN SERENO E FELICE

 2013