March 21, 2007, 10:15 PM CT

Amount of Mercury Entering the Ocean

Scientists from the Woods Hole Oceanographic Institution (WHOI) have found a new and substantial pathway for mercury pollution flowing into coastal waters. Marine chemists have detected much more dissolved mercury entering the ocean through groundwater than from atmospheric and river sources.

Mercury is toxic to animals and humans in large concentrations, especially in the form known as methyl mercury, which accumulates in fish. To date, WHOI scientists examined total mercury, not the more biologically dangerous form, though that is a logical next step. These initial findings of mercury moving through the coastal groundwater system are significant for scientists trying to quantify the impact of mercury in the marine environment.

The lead author of the study is Sharon Bone, a former undergraduate summer student fellow and research assistant in the laboratory of WHOI marine chemist Matt Charette. Bone is now a first-year graduate student at the University of California at Berkeley.

The findings were published online on March 21 by the journal Environmental Science and Technology and will appear in a printed issue later this spring.

Mercury pollution comes mostly from industrial emissions to the atmosphere, particularly from coal burning. After getting into the air, mercury particles eventually precipitate with rain or snow onto the land or directly into the oceans. Inland deposits of mercury are also weathered and carried to the coast in runoff from streams and rivers, where they accumulate in the sediments that build up along the shoreline......... Posted by: Tyler      Read more         Source

March 21, 2007, 9:56 PM CT

Tool To Track Atmospheric Carbon Dioxide

Researchers from NOAA's Earth System Research Laboratory announced recently a new tool to monitor changes in atmospheric carbon dioxide and other greenhouse gases by region and source. The tool, called CarbonTracker, will enable its users to evaluate the effectiveness of their efforts to reduce or store carbon emissions.

The online data framework distinguishes between changes in the natural carbon cycle and those occurring in human-produced fossil fuel emissions. It also provides verification for researchers using computer models to project future climate change. Potential users include corporations, cities, states and nations assessing their efforts to reduce or store fossil fuel emissions around the world.

"NOAA encourages science that adds benefit to society and the environment. CarbonTracker does both," said retired Navy Vice Admiral Conrad Lautenbacher, Ph.D., undersecretary of commerce for oceans and atmosphere and NOAA administrator. "Increasingly, observations of the Earth are demonstrating a remarkable impact on our understanding of human and natural systems. We are transitioning this understanding gained from intensive research into operations that benefit the environment and the economy".

CarbonTracker distills an accurate assessment of greenhouse-gas increases or decreases. The resolution will increase to observe differences in concentration on finer geographical scales over time as data become available. Using the limited data that currently exist, the model can characterize emissions each month among U.S. regions, such as the West or the Southeast. As the observation network becomes denser, however, policymakers will be able to check the CarbonTracker Web site to compare emissions from urban centers. For instance, the resolution will be fine enough to determine the difference in net emissions from Sacramento as in comparison to San Francisco......... Posted by: Tyler      Read more         Source

March 21, 2007, 5:10 AM CT

Greenhouse gas animation using SCIAMACHY data

Based on three years of observations from the SCIAMACHY instrument aboard ESA's Envisat, researchers have produced the first movies showing the global distribution of the most important greenhouse gases - carbon dioxide and methane - that contribute to global warming.

The importance of cutting emissions from these 'anthropogenic', or manmade, gases has been highlighted recently with European Union leaders endorsing binding targets to cut greenhouse gases by at least 20 percent from 1990 levels by 2020. Further illustrating the urgency to combat global warming, Britain became the first country last week to propose legislation for cutting the gases.

Careful monitoring is essential to ensuring these targets are met, and space-based instruments are new means contributing to this. The SCIAMACHY (Scanning Imaging Absorption Spectrometer for Atmospheric Chartography) instrument, for instance, is the first space sensor capable of measuring the most important greenhouse gases with high sensitivity down to the Earth's surface because it observes the spectrum of sunlight shining through the atmosphere in 'nadir' looking operations.

Dr. Michael Buchwitz and Oliver Schneising from the Institute of Environmental Physics (IUP) at the University of Bremen in Gera number of, led by Prof. Dr. John P. Burrows produced these maps based on SCIAMACHY observations from 2003 to 2005......... Posted by: Tyler      Read more         Source

March 20, 2007, 10:16 PM CT

Prehistoric Hurricane Activity

Hurricanes Katrina and Rita focused the international spotlight on the vulnerability of the U.S. coastline. Fears that a "super-hurricane" could make a direct hit on a major city and cause even more staggering losses of life, land and economy triggered an outpouring of studies directed at every facet of this ferocious weather phenomenon. Now, an LSU professor takes us one step closer to predicting the future by drilling holes into the past.

Kam-biu Liu, George William Barineau III Professor in LSU's Department of Oceanography and Coastal Sciences, is the pioneer of a relatively new field of study called paleotempestology, or the study of prehistoric hurricanes. Liu, a long-time resident of Louisiana, became even more interested in the subject during the aftermath of Hurricane Katrina, when a national debate was sparked concerning hurricane intensity patterns and cycles.

"People were discussing the probability of a Category 5 hurricane making direct impact on New Orleans," said Liu. "That's tricky, because it's never actually happened in history. Even Katrina, though still extremely powerful, was only a Category 3 storm at landfall."

Currently, experts tend to agree that Atlantic hurricane activity fluctuates in cycles of approximately 20-30 years, alternating periods of high activity with periods of relative calm. But records of such events have only been kept for the last 150 years or so. What would happen, Liu wondered, if you looked back thousands of years? Would larger cycles present themselves?......... Posted by: Tyler      Read more         Source

Mon, 19 Mar 2007 04:20:20 GMT

US Government Report: This Winter Was the Warmest Worldwide

Environmentalists have another reason to worry about changing climates after a US government report said this winter was the warmest on record worldwideThis report comes barely a month after the Intergovernmental Panel on Climate Change warned that global warming, a man-made issue, is so severe that it would continue for centuries.

The National Oceanic and Atmospheric Administration came out with reports that the combined land and ocean temperatures in the Northern Hemisphere for the December- February period were 1.3 degrees Fahrenheit (0.72 Celsius) above average since record keeping began in 1880. Posted by: Irani      Read more     Source

Tue, 13 Mar 2007 02:26:36 GMT

What Makes Singapore More Vulnerable to Earthquake?

Are you planning to construct a building on a reclaimed lafind out first — how quake-resistant are buildings on reclaimed land? Then, think over again, especially if it is in a quake-prone area.

Fan Sau Cheong, an engineering professor at Singapores Nanyang Technological University said,

Reclaimed land is made up of sea sand, so buildings will be shaken up more violently during earthquakes as compared to those on non-reclaimed land, which is solid and will not be liquefied by the shake.

He informed that buildings on reclaimed land may shake twice to thrice the ones on natural land during earthquakes! It is because, sand in reclaimed land slides like liquid when saturated with water — a process called liquefaction.

Last week, about 150 buildings in Singapore were rattled by a 6.3 magnitude earthquake. Hundreds of people in the financial district had to flee their offices, though no buildings were damaged and nobody was hurt.

Is Singapores vulnerability to such earth-quake related disasters due to nearly 20 per cent of its land-scarce surface area being reclaimed from the sea? And if it is so, there is a justification of the needed worries on it.

Singapore has scores of tower blocks, hotels, factories and petrochemical plants standing on reclaimed land. And to look forward to, the city-state is planning development of a second financial centre, and that too, all on reclaimed land in the Marina Bay area!

Posted by: Irani      Read more     Source

March 8, 2007, 8:03 AM CT

Hurricane Can Form New Eyewall

Hurricanes can gain or lose intensity with startling quickness, a phenomenon never more obvious than during the historic 2005 hurricane season that spawned the remarkably destructive Katrina and Rita.

Scientists flew through Rita, Katrina and other 2005 storms trying to unlock the key to intensity changes. Now, data from Rita is providing the first documented evidence that such intensity changes can be caused by clouds outside the wall of a hurricane's eye coming together to form a new eyewall.

"The comparison between Katrina and Rita will be interesting because we got excellent data from both storms. Rita was the one that showed the eyewall replacement," said Robert Houze Jr., a University of Washington atmospheric sciences professor and lead author of a paper detailing the work in the March 2 edition of the journal Science.

"The implication of our findings is that some new approaches to hurricane forecasting might be possible," he said.

Houze and Shuyi Chen, an associate professor of meteorology and physical oceanography at the University of Miami Rosenstiel School of Marine and Atmospheric Science, lead a scientific collaboration called the Hurricane Rainband and Intensity Change Experiment. The project is designed to reveal how the outer rainbands interact with a hurricane's eye to influence the storm's intensity. Chen is a co-author of the Science paper, as are Bradley Smull of the UW and Wen-Chau Lee and Michael Bell of the National Center for Atmospheric Research in Boulder, Colo......... Posted by: Tyler      Read more         Source

March 8, 2007, 7:58 AM CT

Exploring Earth's Deepest Sinkhole

Researchers return this week to the world's deepest known sinkhole, Cenote Zacaton in Mexico, to resume tests of a NASA-funded robot called DEPTHX, designed to survey and explore for life in one of Earth's most extreme regions and potentially in outer space.

If all goes well with this second round of testing and exploration, the team will return in May for a full-scale exploration of the Zacaton system.

Sinking more than 1,000 feet, Zacaton has only been partially mapped and its true depth remains unknown.

During eight years of research, doctoral student Marcus Gary and hydrogeology professor Jack Sharp from The University of Texas at Austin's Jackson School of Geosciences discovered the system's unusual hydrothermal nature is analogous to liquid oceans under the icy surface of Jupiter's moon Europa.

Technology developed to explore the sinkholes could be applied to future space probes of Europa, where researchers think that deep cracks and holes in the ice offer a chance of finding extraterrestrial life.

The technology could also be used to explore Earth's ice-bound polar lakes, which hold clues to the origins of life on Earth.

Microbes which appear to be new to science have been discovered floating in deep water and lining rocks in Zacaton. Far below sunlight's ability to penetrate, they may get their energy from nutrients welling up from hot springs. Gary and others speculate that previously undocumented life may await discovery in the murky depths......... Posted by: Tyler      Read more         Source

March 6, 2007, 3:37 PM CT

Amazonian Basin Not Well-Populated

There's a scholarly debate brewing about whether pre-Columbian Amazonian populations settled in large numbers across Amazonia and created the modern forest setting that a number of conservationists take to be 'natural.'.

This view has become fashionable among a number of archaeologists and anthropologists, and is challenged in a recent paper from Dr. Mark Bush of the Florida Institute of Technology. The findings of Bush's research may rekindle a debate has major implications for land use and policy-setting in the rain forest.

"We don't contradict that there were major settlements in key areas flanking the Amazon Channel -- there could have been millions of people living there," says Mark Bush, a British-born paleo-ecologist who travels to extremely remote rain forest locations to collect core samples from ancient lakes. He then analyzes those samples for pollen and charcoal and thus is able to conclude with a high degree of accuracy the extent of human settlement in that region.

"What we do say is that when you start to look away from known settlements, you may see very long-term local use," he says. "These people didn't stray very far from home, or from local bodies of water for several thousands of years. We looked at clusters of lakes and landscapes where people lived, and asked, did they leave their homesite to farm around other nearby lakes? No they didn't. These findings argue for a very localized use of Amazonian forest resources outside the main, known, archaeological areas"......... Posted by: Tyler      Read more         Source

March 5, 2007, 8:44 PM CT

Atlantic Ocean Warming and Stronger Hurricanes

Atmospheric researchers have uncovered fresh evidence to support the theory that global warming has contributed to the emergence of stronger hurricanes in the Atlantic Ocean. But the trend doesn't hold up in the world's other oceans.

Researchers funded by the National Science Foundation (NSF) and affiliated with the University of Wisconsin-Madison and NOAA's National Climatic Data Center (NCDC) in Asheville, N.C., reported the findings in the journal Geophysical Research Letters. The work should help clarify two studies last year that drew connections between global warming and increasingly intense hurricanes.

"Documenting trends in hurricane intensity is made more difficult by sparse observations and has led to debates about whether the trends are real, or are artifacts of observations," says Jay Fein, program director in NSF's division of atmospheric sciences. "This study has directly addressed this point by using, for the first time, a new satellite data set to look at hurricane trends".

For decades, hurricane scientists found it difficult to work with the inconsistent nature of hurricane data. Before the advent of weather satellites, researchers were forced to rely on scattered ship reports and sailor logs to stay abreast of storm conditions. The advent of weather satellites during the 1960s dramatically improved the situation, but the technology has changed so rapidly that newer satellite records are barely consistent with older ones......... Posted by: Tyler      Read more         Source