Tag Archives: Antarctica

Remote Clouds Responsible for Climate Models’ Glitch in Tropical Rainfall

By Guest PostMarch 14, 2013EnvironmentAntarctica, atmospheric scientists, clouds, dargan frierson, equatorial africa, future pattern, global climate models, global climate predictions, Java, modern climate models, prediction, rain in zambia, rainfall, rainfall forecasts, rainfall patterns, shift, simulation of cloud, southern hemisphere, Southern Ocean, tropical island, tropical rainfall, university of washington, warmer ocean temperatures, yen ting hwang

It seems counterintuitive that clouds over the Southern Ocean, which circles Antarctica, would cause rain in Zambia or the tropical island of Java. But new research finds that one of the most persistent biases in global climate models – a phantom band of rainfall just south of the equator that does not occur in reality – is caused by poor simulation of the cloud cover thousands of miles farther to the south.

University of Washington atmospheric scientists hope their results help explain why global climate models mistakenly duplicate the inter-tropical convergence zone, a band of heavy rainfall in the northern tropics, on the other side of the equator. The study appears this week in the Proceedings of the National Academy of Sciences. (more…)

The Making of Antarctica’s Hidden Fjords

By Guest PostMarch 8, 2013Environmentantarctic ice sheet, Antarctica, antarctica topography, columbia university, cooling age, east antarctica, erosion rate, fjords, geologists, george e gehrels, geoscientist, geoscientists, glaciers, global climate, hidden fjords, ice sheet growth, lambert glacier, marine technician, mountains, national science foundation, ocean drilling program, pattern, peter w reiners, prydz bay, rock, rocks, sample, sea level change, sea-level rise, sediments, sidney r hemming, stuart n thomson, ty cobb, university of arizona

Antarctica’s topography began changing from flat to fjord-filled starting about 34 million years ago, according to a new report from a University of Arizona-led team of geoscientists.

Knowing when Antarctica’s topography started shifting from a flat landscape to one with glaciers, fjords and mountains is important for modeling how the Antarctic ice sheet affects global climate and sea-level rise. (more…)

Analysis of Greenland Ice Cores Adds to Historical Record and May Provide Glimpse into Climate’s Future

By Guest PostJanuary 30, 2013Environmentalpine research, Antarctica, Arctic, arctic sciences section, atmosphere, belgium, boulder, canada, change, China, climate, climate conditions, denmark, dorthe dahl-jensen, earth climate, eemian interglacial, eemian like, eemian period, france, future, future climate, Germany, global temperatures rise, greenland ice cores, greenland ice sheet, historical record, ice ages, ice sheet, Iceland, Japan, jim white, last interglacial period, national science foundation, neem, northern greenland, northern hemisphere, paleo climate models, sea-level rise, south korea, subsurface ice layers, Sweden, switzerland, the netherlands, united kingdom, united states, university of colorado, university of copenhagen, west antarctic

The International North Greenland Eemian Ice Drilling (NEEM) project results indicate that melting of Antarctic ice sheet may have contributed more to sea level rise than melting of the Greeland ice sheet some 100,000 years ago

A new study that provides surprising details on changes in Earth’s climate from more than 100,000 years ago indicates that the last interglacial–the period between “ice ages”–was warmer than previously thought and may be a good analog for future climate, as greenhouse gases increase in the atmosphere and global temperatures rise.

The research findings also indicate that melting of the massive West Antarctic ice sheet may have contributed more to sea-level rise at that time than melting of the Greenland ice sheet. (more…)

Study Shows Rapid Warming on the West Antarctic Ice Sheet

By Guest PostDecember 25, 2012Environmentandrew monaghan, Antarctic, Antarctica, below sea level, byrd station, climate change, contribution, data, david bromwich, discovery, earth, greenland, ice sheet, ice shelf, ice shelves, julien nicolas, larsen b, meteorological observation, ocean, ohio state university, polar night, sea-level rise, solar panels, southern hemisphere, surface melting, temperature, wais, wais glaciers, warming, west antarctic

COLUMBUS, Ohio — In a discovery that raises further concerns about the future contribution of Antarctica to sea level rise, a new study finds that the western part of the ice sheet is experiencing nearly twice as much warming as previously thought.

The temperature record from Byrd Station, a scientific outpost in the center of the West Antarctic Ice Sheet (WAIS), demonstrates a marked increase of 4.3 degrees Fahrenheit (2.4 degrees Celsius) in average annual temperature since 1958—that is, three times faster than the average temperature rise around the globe. (more…)

Climate Change Study Strengthens Link to Human Activities

By Guest PostDecember 5, 2012EnvironmentAntarctica, Arctic, atmospheric temperature, benjamin santer, berkeley lab, carbon dioxide, cfcs, chlorofluorocarbons, climate change, climate models, coolants, el niño, evidence, greenhouse gases, higgs boson, human factors, human influence, llnl, michael wehner, pacific decadal oscillation, phenomena, propellants, satellite data, simulations, southern oscillation, stratospheric temperature, tropospheric, tropospheric warming

Computer Models, Satellite Data Reveal Clearest Evidence Yet of Human Influence on Changing Temperatures

New research shows some of the clearest evidence yet of a discernible human influence on atmospheric temperature.

Published online in the Nov. 29 early edition of the Proceedings of the U.S. National Academy of Sciences, the study compared 20 of the latest climate models against 33 years of satellite data. When human factors were included in the models, they followed the pattern of temperature changes observed by satellite. When the same simulations were run without considering human influences, the results were quite different.

“We can only match the satellite record when we add in human influences on the atmosphere,” said Michael Wehner, a research scientist at Lawrence Berkeley National Laboratory (Berkeley Lab) Computational Research Division and a coauthor of the article, which involved colleagues from 16 other organizations and was led by Benjamin Santer, an atmospheric scientist at Lawrence Livermore National Laboratory (LLNL). (more…)

Ecologists Shed New Light on Effects of Light Pollution on Wildlife

By Guest PostDecember 3, 2012Environment, Naturealarm calls, animal behaviour, Antarctica, artificial light, asia, common redshank, data, earth, ecologist, electrical lighting, Europe, exeter, feeding habit, forth estuary, full moon, gas flare, grangemouth, light pollution, longannet, marshes, negative effect, nervous birds, oil refinery, power station, ross dwyer, satellite, scotland, sentinel, shorebirds, spring migration, teu hoo, uk coasts, university, us military, wildlife

Light pollution is often associated with negative effects on wildlife. Now, ecologists have found that by mimicking a perpetual full moon, the gas flares and electrical lighting along Scotland’s Forth estuary are helping shorebirds stock up on more food during the winter to fuel their spring migration.

The research is the first to use night-time light data from US military satellites to study animal behaviour.

Coasts and estuaries are among the most rapidly developing areas on Earth. Night-time satellite images of the planet show that except Antarctica, continents are ringed with halos of brightly-lit human development. But coasts are also key wildlife sites. Every year, millions of waterbirds arrive from the Arctic to overwinter on UK coasts, yet scientists remain largely in the dark about how these birds respond to the bright lights of coastal cities and industry. (more…)

Scientists Uncover Vast Differences in Earth’s Polar Ocean Microbial Communities

By Guest PostOctober 10, 2012Environmentalison murray, Antarctica, arctic ocean, biodiversity, biodiversity pattern, biogeographically, canada, changing climate, coast, community, continental, drainage basin, earth, environmental selection, flow, france, freshwater, glacial melt, global ocean, jean françois ghiglione, kevin bakker, marine, marine life, marine microbe, michigan, microbial community, microbial diversity, new zealand, ocean, oceanic circulation, oden, polar ocean, polar region, polar year, pole, sea ice, sloan foundation, southern, spain, structure, Sweden, swedish icebreaker, united states, university

ANN ARBOR— An international team of scientists, including a University of Michigan graduate student, has demonstrated that a clear difference exists between the marine microbial communities in the Southern and Arctic oceans, contributing to a better understanding of the biodiversity of marine life at the poles.

The most comprehensive comparison of microbial diversity at both of Earth’s polar oceans showed that about 75 percent of the organisms at each pole are different. This insight sheds light on newly recognized biodiversity patterns and reinforces the importance of studying Earth’s polar regions in the face of a changing climate. And it highlights the need for further research on the impacts of sea ice, seasonal shifts and freshwater input in both regions. (more…)

First Stars, Galaxies Formed more Rapidly than Expected

By Guest PostSeptember 9, 2012Scienceanalysis, anisotropy probe, Antarctica, astronomer, background, Berkeley, california, christian reichardt, cmb, cosmic microwave, cosmological evolution, data, earth axis, electron, Epoch, Galaxy, geographic, herschel satellite, high resolution, hydrogen atom, image, john carlstrom, kavli foundation, microwave, millimeter wavelength, national, neutral, neutral gas, oliver zahn, period, plasma, polar plateau, proton, radiation, reionization, s chandrasekhar, science foundation, south pole, star, telescope, ultraviolet light, universe, university, wilkinson

Analysis of data from the National Science Foundation’s South Pole Telescope, for the first time, more precisely defines the period of cosmological evolution when the first stars and galaxies formed and gradually illuminated the universe. The data indicate that this period, called the epoch of reionization, was shorter than theorists speculated — and that it ended early.

“We find that the epoch of reionization lasted less than 500 million years and began when the universe was at least 250 million years old,” said Oliver Zahn, a postdoctoral fellow at the Berkeley Center for Cosmological Physics at the University of California, Berkeley, who led the study. “Before this measurement, scientists believed that reionization lasted 750 million years or longer, and had no evidence as to when reionization began.” (more…)