Is the ice at the South Pole melting?

Gravity field satellites observe for the first time the fluctuations of ice mass of the Antarctic ice sheet due to El Nino

2010-10-30

(Press-News.org) The change in the ice mass covering Antarctica is a critical factor in global climate events. Scientists at the GFZ German Research Centre for Geosciences have now found that the year by year mass variations in the western Antarctic are mainly attributable to fluctuations in precipitation, which are controlled significantly by the climate phenomenon El Nino. They examined the GFZ data of the German-American satellite mission GRACE (Gravity Recovery and Climate Experiment). The investigation showed significant regional differences in the western coastal area of the South Pole area.

Two areas in Antarctica are of particular interest because of their potential sensitivity to global climate change: the Antarctic Peninsula, which is currently experiencing a warming exceeding the global mean and the disappearance of large ice shelf areas, and the Amundsen Sector of West Antarctica, where currently the largest flow rates and mass loss of the Antarctic Ice Sheet is occurring. For some glaciers the ice thickness is decreasing rapidly, and glaciers and ice streams are notably retreating back into the interior. With 0.3 millimeters per year, both regions are currently contributing considerably to the global sea level change of about three millimeters per year.

In the study, the mass balance of both regions is reevaluated from gravity data of the satellite mission GRACE. As a result, the estimates were lower than those of conventional mass balance methods. "With the GRACE time series, it was for the first time possible to observe how the large-scale ice mass varies in the two areas due to fluctuations in rainfall from year to year," said the GFZ scientists Ingo Sasgen. It has long been known that the Pacific El Niño climate phenomenon and the snowfall in Antarctica are linked. The complementary piece to the warm phase El Nino, the cold phase known as La Nina, also affects the Antarctic climate: "The cooler La Nina years lead to a strong low pressure area over the Amundsen Sea, which favors heavy rainfall along the Antarctic Peninsula - the ice mass is increasing there. In contrast, the Amundsen area is dominated by dry air from the interior during this time. El Nino years with their warm phase lead to precisely the opposite pattern: reduced rainfall and mass loss in the Antarctic Peninsula, and an increase in the Amundsen Sectorfield, respectively" explains Professor Maik Thomas, head of the section "Earth System Modelling" at the German Research Centre for Geosciences (Helmholtz Association).

The recording of the entire ice mass of the South Pole and its variations is a central task in climate research and still raises many unanswered questions. In principle, the study could show that the continuous gravity data of the GRACE satellite mission contain another important medium-term climate signal.

INFORMATION: Sasgen, I. Dobson, H., Martinec, Z. and Thomas, M., "Satellite Gravimetry Observation of Antarctic Snow Accumulation Related to ENSO," Earth and Planetary Science Letters (2010), doi: 10.1016/j.epsl.2010.09 .015.

Images in printable resolution can be found at: http://www.gfz-potsdam.de/portal/gfz/Public Relations/M40-Bildarchiv/Bildergalerie_Satelliten/04 Gallery GRACE

ELSE PRESS RELEASES FROM THIS DATE:

Stereotactic radiotherapy slows pancreatic cancer progression for inoperable patients

2010-10-30

DETROIT – For pancreatic cancer patients unable to undergo surgery – the only known cure for this form of cancer – a highly targeted cancer radiation therapy may help slow cancer progression and lessen disease symptoms, according to researchers at Henry Ford Hospital in Detroit. Called stereotactic body radiotherapy (SBRT), the study found it was able to delay pancreatic cancer progression locally, on average, by almost six months. While, on average, the patients in the study lived about 10 months, one-third lived more than a year. Without any treatment – surgery, ...

Women's unique connection to nature is explored in special issue of Ecopsychology

2010-10-30

New Rochelle, NY, October 29, 2010—Women experience and interact with their natural surroundings in ways that differ from men. The way in which those differences affect a woman's sense of self, body image, and drive to protect and preserve the environment are explored in a thought-provoking special issue of Ecopsychology, a peer-reviewed, online journal published by Mary Ann Liebert, Inc. (www.liebertpub.com). The entire issue is available free online at www.liebertpub.com/eco Guest Editors Britain Scott, PhD, from the University of St. Thomas (St. Paul, MN) and Lisa ...

Parents' effort key to child's educational performance

2010-10-30

A new study by researchers at the University of Leicester and University of Leeds has concluded that parents' efforts towards their child's educational achievement is crucial – playing a more significant role than that of the school or child. This research by Professor Gianni De Fraja and Tania Oliveira, both in the Economics Department at the University of Leicester and Luisa Zanchi, at the Leeds University Business School, has been published in the latest issue of the MIT based Review of Economics and Statistics. The researchers found that parents' effort is more ...

Wartime urologic injuries require different mindset

2010-10-30

AUGUSTA, Ga. – Saving a soldier's life takes precedence over treating traumatic urologic injuries on the battlefield, a Medical College of Georgia researcher says. Injuries to the bladder, ureters, kidneys and external genitalia often require complex surgical treatment, said Dr. Arthur Smith, an MCG urologist. But during wartime, when those wounds are often combined with other life-threatening injuries, their treatment becomes secondary to lifesaving tactics. Smith made his comments at a lecture, Revised Management Strategies for Urologic Injuries During Wartime, at ...

Women with anorexia nervosa more likely to have unplanned pregnancies

2010-10-30

CHAPEL HILL, N.C. – A new study by University of North Carolina at Chapel Hill and Norwegian researchers has found that women with anorexia nervosa are much more likely to have both unplanned pregnancies and induced abortions than women who don't have the serious eating disorder. These results may be driven by a mistaken belief among women with anorexia that they can't get pregnant because they are either not having menstrual periods at all or are having irregular periods, said Cynthia M. Bulik, PhD, the study's lead author and director of the UNC Eating Disorders Program. "Anorexia ...

Is the shape of a genome as important as its content?

2010-10-30

If there is one thing that recent advances in genomics have revealed, it is that our genes are interrelated, "chattering" to each other across separate chromosomes and vast stretches of DNA. According to researchers at The Wistar Institute, many of these complex associations may be explained in part by the three-dimensional structure of the entire genome. A given cell's DNA spends most of its active lifetime in a tangled clump of chromosomes, which positions groups of related genes near to each other and exposes them to the cell's gene-controlling machinery. This structure, ...

Scientists seek urgent treatment for fatal sleeping sickness

2010-10-30

Urgently-needed new treatment for a parasitic disease is being investigated in research led at the University of Strathclyde in Glasgow, Scotland. Human African Trypanosomiasis, also known as sleeping sickness, affects between 50,000 and 70,000 people in Africa and South America. It is transmitted through the bite of the tsetse fly and attacks the nervous system and brain, leading to fever, headaches and disturbed sleep patterns. Without treatment, the disease is fatal but a new drug to tackle it is being developed in a project led at Strathclyde, with partners from ...

Raising giant insects to unravel ancient oxygen

2010-10-30

Boulder, CO, USA - The giant dragonflies of ancient Earth with wingspans of up to 70 centimeters (28 inches) are generally attributed to higher oxygen atmospheric levels in the atmosphere in the past. New experiments in raising modern insects in various oxygen-enriched atmospheres have confirmed that dragonflies grow bigger with more oxygen, or hyperoxia. However, not all insects were larger when oxygen was higher in the past. For instance, the largest cockroaches ever are skittering around today. The question becomes how and why do different groups respond to changes ...

Troubled islands: Hurricanes, oil spill and sea level rise

2010-10-30

Boulder, CO, USA - The islands flanking the outlet of the Mississippi River are not only facing losses due to sea level rise and local subsidence, according to one study, but new unknown impacts from oil recovery operations, say researchers working on another project. Both will be presenting their work on Nov. 1 and 2 at the meeting of the Geological Society of American in Denver. Some islands could disappear entirely in coming decades, exposing huge swaths of marshland to the waves of the open sea. On one side of the Mississippi River outlet, to the east of the river ...

Newly discovered gene enables fish to 'disappear'

2010-10-30

Researchers led by Vanderbilt's Roger Cone, Ph.D., have discovered a new member of a gene family that has powerful influences on pigmentation and the regulation of body weight. The gene is the third member of the agouti family. Two agouti genes have been identified previously in humans. One helps determine skin and hair color, and the other may play an important role in obesity and diabetes. The new gene, called agrp2, has been found exclusively in bony fish, including zebrafish, trout and salmon. The protein it encodes enables fish to change color dramatically to match ...

LAST 30 PRESS RELEASES:

The American Society of Tropical Medicine and Hygiene and the Bill & Melinda Gates Foundation announce new research fellowship in malaria genomics in honor of professor Dominic Kwiatkowski