July 22, 2008, 8:12 PM CT

System to Forecast Flash Floods

People living near vulnerable creeks and rivers along Colorado's Front Range may soon get advance notice of potentially deadly floods, thanks to a new forecasting system being tested this summer by the National Center for Atmospheric Research (NCAR) in Boulder, Colo.

Known as the NCAR Front Range Flash Flood Prediction System, it combines detailed atmospheric conditions with information about stream flows to predict floods along specific streams and catchments.

"The goal is to provide improved guidance about the likelihood of a flash flood event a number of minutes out to an hour or two before the waters start rising," says NCAR scientist David Gochis, one of the developers of the new forecasting system. "We want to increase the lead time of a forecast, while decreasing the uncertainty about whether a flood will occur".

Funding to create the system came from the National Science Foundation (NSF), which is NCAR's sponsor, as well as the National Oceanic and Atmospheric Administration.

"This project is an excellent example of using basic research findings to improve forecasts important to saving lives," said Cliff Jacobs, program director in NSF's Division of Atmospheric Sciences.

The Front Range, because of its steep topography and intense summer storms, is uncommonly vulnerable to summertime flash floods. Such floods have claimed the lives of hundreds of people and accounted for hundreds of millions of dollars in damages throughout the region's history......... Posted by: Tyler      Read more         Source

July 21, 2008, 9:39 PM CT

Key to saving the world's lakes

After completing one of the longest running experiments ever done on a lake, scientists from the University of Alberta, University of Minnesota and the Freshwater Institute, contend that nitrogen control, in which the European Union and a number of other jurisdictions around the world are investing millions of dollars, is not effective and in fact, may actually increase the problem of cultural eutrophication.

The dramatic rise in cultural eutrophicationthe addition of nutrients to a body of water due to human activity that often causes huge algal blooms, fish kills and other problems in lakes throughout the worldhas resulted from increased deposits of nutrients to lakes, largely from human sewage and agricultural wastes.

For 37 years scientists looked at Lake 227, a small lake in the Canadian Shield at the Experimental Lakes Area (ELA) in Ontario, Canada, and examined the best ways to control the cultural eutrophication process of lakes by varying the levels of phosphorous and nitrogen added to the lake.

"What we found goes against the practices of the European Union and a number of researchers around the world," said David Schindler, professor of ecology at the University of Alberta and one of the leading water scientists in the world. "Controlling nitrogen does not correct the polluted lakes, and in fact, may actually aggravate the problem and make it worse"......... Posted by: Tyler      Read more         Source

July 20, 2008, 2:54 PM CT

Saharan dust storms sustain life in Atlantic Ocean

Research at the University of Liverpool has found how Saharan dust storms help sustain life over extensive regions of the North Atlantic Ocean.

Working aboard research vessels in the Atlantic, researchers mapped the distribution of nutrients including phosphorous and nitrogen and investigated how organisms such as phytoplankton are sustained in areas with low nutrient levels.

They observed that plants are able to grow in these regions because they are able to take advantage of iron minerals in Saharan dust storms. This allows them to use organic or 'recycled' material from dead or decaying plants when nutrients such as phosphorous an essential component of DNA in the ocean are low.

Professor George Wolff, from the University's Department of Earth and Ocean Sciences, explains: "We observed that cyanobacteria a type of ancient phytoplankton are significant to the understanding of how ocean deserts can support plant growth. Cyanobacteria need nitrogen, phosphorous and iron in order to grow. They get nitrogen from the atmosphere, but phosphorous is a highly reactive chemical that is scarce in sea water and is not found in the Earth's atmosphere. Iron is present only in tiny amounts in sea water, even though it is one of the most abundant elements on earth......... Posted by: Tyler      Read more         Source

July 17, 2008, 9:32 PM CT

Digital cameras, remote satellites measure crop water demand

Horticultural crops account for almost 50% of crop sales in the United States, and these crops are carefully managed to ensure good quality. But more information is needed about the crops' growth and response to seasonal and climatic changes so that management practices such as irrigation can be precisely scheduled. Existing research can be difficult to generalize because of variations in crops, planting densities, and cultural practices.

Determining growth stage, size, and water needs are particularly important for horticultural crops because most crops are grown in limited water environments and require irrigation. The measurement of "canopy light interception" is a primary means of determining water and irrigation needs. Fractional canopy cover (CC) is a relatively easily measured property that is a good indicator of light interception. Canopy cover, the percent of the soil surface covered by plant foliage, is an important indicator of stage of growth and crop water use in horticultural crops. Methods of using remote sensors to determine canopy cover in major crops have been studied for years, but the studies have not included most horticultural crops.

Thomas J. Trout, Research Leader at the U.S. Department of Agriculture's Agricultural Research Service, along with colleagues from the NASA Earth Science Division, recently published a study that addresses the relationship of remotely sensed normalized difference vegetation index (NDVI) relative to canopy cover of several major horticultural crops in commercial fields......... Posted by: Tyler      Read more         Source

July 15, 2008, 10:32 PM CT

Corporations Can Profit From Being Environmentally Friendly

Though a number of policymakers have argued that environmental regulations can negatively impact an organization's bottom line, a new study by George Mason University researcher Nicole Darnall shows that companies that develop green production processes can not only offset the costs of regulations, but can also reap further benefits.

The study, which looked at more than 2,600 manufacturing facilities operating in seven different countries, showed that more stringent environmental policies are correlation to diminished company profits. However, organizations that improve their environmental performance by enhancing their internal efficiencies and developing new green products and technologies can offset the cost of regulation or even accrue a net gain.

"The primary reason why the United States and a number of other countries do not have national climate change policy and do not implement more stringent environmental legislation is due to the costs the regulations would impose on firms," says Darnall, assistant professor of environmental science and policy. "The results of this study are important because realizing that these costs can be offset-or eliminated entirely-is further evidence that policymakers could support the advancement of more ambitious environmental policy goals without putting undue financial burdens on corporations"......... Posted by: Tom      Read more         Source

July 15, 2008, 9:35 PM CT

Scattered nature of Wisconsin's woodlands

If a warmer Wisconsin climate causes some northern tree species to disappear in the future, it's easy to imagine that southern species will just expand their range northward as soon as the conditions suit them.

The reality, though, may not be nearly so simple. A model developed by University of Wisconsin-Madison forest ecologists Robert Scheller and David Mladenoff suggests that while certain northern species, such as balsam fir, spruce and jack pine, are likely to decline as the state's climate warms, oaks, hickories and other southern Wisconsin trees will be slow to replace them.

Why? Not only is warming expected to outpace the speed at which southern trees can migrate northward, but barriers to dispersal - especially agricultural lands - will also likely delay their progress, says Mladenoff.

"The result is that northern forest biomass in the future - that is, the standing amount of forest - could decrease, because the trees that are there now will be experiencing less than optimal conditions," he says. "And the southern species aren't going to fill in as quickly as we'd like." He and Scheller report their findings in the current issue of Climate Research

Mladenoff explains that trees "move" into new areas by producing seeds, which are then carried over short distances by wind, birds or mammals. Under the right conditions, dispersed seeds then grow into seedlings and eventually mature trees, which produce their own seeds to start the process all over again......... Posted by: Tyler      Read more         Source

July 15, 2008, 9:29 PM CT

Future snowmelt in West twice as early as expected

As per a new study, global.

warming could lead to larger changes in snowmelt in the western United States than was previously thought, possibly increasing wildfire risk and creating new water management challenges for agriculture, ecosystems and urban populations.

Researchers, including a Purdue University professor of earth and atmospheric sciences, discovered that a critical surface temperature feedback is twice as strong as what had been projected by earlier studies.

The high-resolution climate model used by the team was better able to reproduce the complex topography of the western United States and capture details of the effect of snow cover on the climate system, as well as the historical record of runoff.

The findings will be published in an upcoming issue of Geophysical Research Letters and are now available online at the journal's Web site.

Noah Diffenbaugh, senior author of the paper and an associate professor of earth and atmospheric sciences at Purdue, said the influence of melting snow on regional climate is far greater than that of increased greenhouse gases alone.

"The heat trapping from elevated greenhouse gases triggers the warming, but the additional warming caused by the loss of snow is what really creates the big changes in surface runoff," said Diffenbaugh, who also is a member of Purdue's Climate Change Research Center. "Researchers have known about this general effect for years. The big surprise here is how much the complex topography plays a role, essentially doubling the threat to water resources in the West"......... Posted by: Tyler      Read more         Source

July 14, 2008, 5:12 PM CT

Potential Effects Of Volcanic Eruptions

For the first time, scientists have taken a detailed look at what lies beneath all of Iceland's volcanoes - and found a world far more complex than they ever imagined.

They mapped an elaborate maze of magma chambers - work that could one day help researchers better understand how earthquakes and volcanic eruptions occur in Iceland and elsewhere in the world.

Knowing where magma chambers are located is a key first step to understanding the chemical composition of the molten rock that is flowing within them - and of the gases that are released when a volcano erupts, explained Daniel Kelley, doctoral student in earth sciences at Ohio State University.

Kelley and Michael Barton, professor of earth sciences at Ohio State, have determined that the volcanoes in Iceland are likely to have explosive eruptions that shoot debris far into the atmosphere. That's because the magma moves very quickly to the surface from deep within the magma chambers. Fast-moving magma propels sulfur and ash out of a volcano and high into the atmosphere, where it can spread around the planet.

"One of the reasons we're trying to understand these volcanoes is to determine exactly what the chances are of a large eruption there. We know that a large eruption in Iceland would not only have devastating local effects, but potential global effects as well - by affecting the climate," Barton said......... Posted by: Tyler      Read more         Source

July 14, 2008, 5:00 PM CT

China can't fully fix air quality problem for Olympics

The outlook for air quality in Beijing during the Olympics is borderline, and there's little that the Chinese government can do to improve it. That's the conclusion drawn by a University of Rhode Island atmospheric chemist who analyzed pollution data collected regularly for the last five years by Chinese scientists.

"There is both a local component and a regional component to the pollutants that cause unhealthy air in Beijing, and the severity of their effects are driven by weather fronts and winds," said Kenneth Rahn, a retired URI professor who travels to China several times a year to help researchers at Tsinghua University interpret their data. "Since it's controlled by the weather, it will be a matter of luck whether the bad air periods correspond with days of outdoor Olympic events".

Locally generated pollutants in Beijing consist primarily of organic matter from transportation, factories and cooking, while regional sources of pollution include ammonium sulfates and ammonium nitrates from coal-burning power plants, industry and transportation sources, which are easily transported long distances in the atmosphere, as per Rahn.

"The air pollution pattern in Beijing is unusual, with high and low concentrations that can differ by a factor of 50 to 100," Rahn said. "When the winds shift to the north and bring in clear air from Mongolia, the air can be relatively clean, though that's not the norm during the summer. But when winds are from the south, where there is a large population and lots of industrial activity, the air can be especially hazardous"......... Posted by: Tyler      Read more         Source

July 10, 2008, 9:27 PM CT

Wilkins Ice Shelf hanging by its last thread

The Wilkins Ice Shelf is experiencing further disintegration that is threatening the collapse of the ice bridge connecting the shelf to Charcot Island. Since the connection to the island in the image centre helps to stabilise the ice shelf, it is likely the break-up of the bridge will put the remainder of the ice shelf at risk.

This animation, comprised of images acquired by Envisat's Advanced Synthetic Aperture Radar (ASAR) between 30 May and 9 July 2008, shows the break-up event which began on the east (right) rather than the on west (left) like the prior event that occurred last month. By 8 July, a fracture that could open the ice bridge was visible.

As per the image acquired on 7 July 2008, Dr Matthias Braun from the Center for Remote Sensing of Land Surfaces at Bonn University estimates the area lost on the Wilkins Ice Shelf during this break-up event is about 1350 km² with a rough estimate of 500 to 700 km² in addition being lost if the bridge to Charcot Island collapses.

This break-up is puzzling to researchers because it has occurred in the Southern Hemispheric winter and does not have characteristics similar to two earlier events that occurred in 2008, which were comparable to the break-up of the Larsen-A and -B ice shelves.

"The scale of rifting in the newly-removed areas seems larger, and the pieces are moving out as large bergs and not toppled, finely-divided ice melange," said Ted Scambos from the National Snow and Ice Data Center who uses ASAR images to track the area......... Posted by: Tyler      Read more         Source