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Photosynthetic Trends In Northern Circumpolar High Latitudes
As per Andrew Bunn, lead author of the paper and a post-doctoral fellow at the Center, "This research suggests that the high latitudes might not be responding to climate change as previously thought. If the ability of boreal forests to capture and store carbon in a warmer world is not as great as we've previously supposed, then we will have to think differently about how the planet will respond to continuing emissions of carbon dioxide." All land surfaces above 50 degree N, excluding the glaciers of Greenland, were included in this study. Growing seasons were defined as May to August though early and late growing season periods were also considered. Three primary data sets derived from polar-orbiting satellites were used. Overall, tundra areas show marked greening over the entire growing season. These patterns were consistent with relatively simple climate response seen in related work in North America, where areas responded to summer maximum temperatures while the response of forest vegetation was more complex. Boreal forests patterns indicate significant greening in May and June, with gains offset by substantive browning in July and August......... Posted by: Jessica Permalink Looking At Hurricane Cloud Tops For Windy Clues
By looking at how high up the rain is forming within clouds, researchers can estimate whether the hurricane's surface winds will strengthen or weaken. They have found that if rain is falling from clouds that extend up to 9 miles high, and that rain continues for at least one out of three hours, a hurricane's surface winds are likely going to get stronger. To see into the cloud tops, NASA researchers developed a precise mathematical method or a technique with the very precise rain measurements from the radar onboard the Tropical Rainfall Measuring Mission (TRMM) satellite. Once this technique was developed it was applied to data collected by National Weather Service radars on the ground. "Thanks to the precise measurements from TRMM, we've found a new way to use data that's collected all the time by weather radars on the ground," said Owen Kelley, scientist at NASA's Goddard Space Flight Center, Greenbelt, Md. Kelley and researchers John Stout of NASA Goddard and Jeff Halverson of the University of Maryland Baltimore County calculated statistics that suggest forecasters could use TRMM's rain-height observations to improve existing observations and computer model forecasts of hurricane winds. "The trick is to keep an eye on the height of rain that radars see when a hurricane approaches within 200 miles of the coast," Kelley said......... Posted by: Tyler Permalink Source Scientists Study How Heart Mountain Shifted"Moving mountains" has come to mean doing the impossible. Yet at least once in the past, one mountain relocated a fair distance away. This feat took place around 50 million years ago, in the area of the present-day border between Montana and Wyoming. Heart Mountain was part of a larger mountain range when the 100 km (62 mile) long ridge somehow became detached from its position and shifted about 100 km to the southwest. This "migrating mountain" has garnered interest from geologists and geophysicists around the world who have tried to solve the mystery behind the largest known instance of land movement on the face of any continent. Dr. Einat Aharonov of the Weizmann Institute's Environmental Sciences and Energy Research Department, working in collaboration with Dr. Mark Anders of Columbia University in New York, recently published a paper in the scientific journal Geology that offers an explanation for the phenomenon.Aharonov and Ander's explanation is based on dikes - vertical cracks in the rock that fill with hot lava boiling up from deep in the earth. In Heart Mountain, these dikes formed a passage for the lava, three kilometers deep, through the limestone aquifer (a porous, water-soaked layer). There, the sizzling lava would have heated the water to extreme temperatures, causing tremendous fluid pressures. The researchers developed a mathematical model (based on the number of dikes in the mountain and their structure) that allowed them to calculate the temperatures and pressures that would have been created deep within the base of the mountain. The results showed that the infiltrating hot lava would have turned the water in the aquifer layer into a sort of giant pressure cooker, releasing enough force to move Heart Mountain from its original spot to its present site......... Posted by: Tyler Permalink Source Global Warming May Have Damaged Coral Reefs Forever
Large sections of coral reefs and much of the marine life they support may be wiped out for good, say the international team of researchers, who surveyed 21 sites and over 50,000 square metres of coral reefs in the inner islands of the Seychelles in 1994 and 2005. Their report is the first to show the long-term impact of the 1998 event where global warming caused Indian Ocean surface temperatures to increase to unprecedented and sustained levels, killing off (or 'bleaching') more than 90 per cent of the inner Seychelles coral. The team, led by the University of Newcastle upon Tyne, and which comprises scientists from the UK, Australia and the Seychelles, publishes its findings today, Monday May 15, in the Proceedings of the National Academy of Sciences. The research showed that, while the 1998 event was devastating in the short term, the main long-term impacts are down to the damaged reefs being largely unable to reseed and recover. A number of simply collapsed into rubble which became covered by unsightly algae......... Posted by: Tyler Permalink Source Equatorial African Icecaps To Disappear
Lonnie Thompson, professor of geological sciences, reported that at least one-third of the massive ice field atop Tanzania's Mount Kilimanjaro in Africa has disappeared, or melted, in the last dozen years. About 82 percent of the ice field has been lost since it was first mapped in 1912. And the Peru's Quelccaya ice cap in the Southern Andes Mountains has shrunk by at least 20 percent since 1963. More troubling however, Thompson said, is the observation that the rate of retreat for one of the main glaciers flowing out from the ice cap, Qori Kalis, has been 32 times greater in the last three years than it was in the period between 1963 and 1978. Thompson, a researcher with Ohio State's Byrd Polar Research Center, reported the results of two decades of studies by his research team, which has surveyed tropical ice caps and retrieved and analyzed ice cores from South America, Africa, China, Tibet and other locations around the globe. He presented his findings during the annual meeting of the American Association for the Advancement of Science in San Francisco......... Posted by: Tyler Permalink Source How did cactuses evolve?
Caption: Neoraimondia herzogiana, a member of the leafless, stem-succulent Cactoideae, growing in central Bolivia. Credit: E.J. Edwards
"The cactus form is often heralded as a striking example of the tight relationship between form and function in plants," write the authors. "A succulent, long-lived photosynthetic system allows cacti to survive periods of extreme drought while maintaining well-hydrated tissues." Recent molecular phylogenetic work has confirmed that Pereskia, a genus that consists of 17 species of leafy shrubs and trees, is where the earliest cactus lineages began. Using field studies and environmental modeling, Edwards and Donoghue found that the Pereskia species already showed water use patterns that are similar to the leafless, stem-succulent cacti. "[Our] analyses suggest that several key elements of cactus ecological function were established previous to the evolution of the cactus life form," explain the authors. "Such a sequence may be common in evolution, but it has rarely been documented as few studies have incorporated physiological, ecological, anatomical, and phylogenetic data."........ Posted by: Jessica Permalink Source Pollution, Greenhouse Gases And Climate Clash In South Asia
A photo from Beijing, China, in March 2005 illustrates one of the many pollution hazes over major urban areas.
As per a research findings reported in the May 15 issue of the American Meteorological Society's Journal of Climate, Chul Eddy Chung and V. Ramanathan of Scripps Oceanography describe their analysis of sea-surface temperatures and a range of other data from the Indian Ocean region. In the analysis, they found that cooler-than-normal temperatures in the northern part of the ocean have weakened the natural climate circulation and monsoon conditions in the region, resulting in reduced rainfall over India and increased rainfall over the Sahel area south of the Sahara in Africa. As the tropical Indian Ocean heats up due to greenhouse gases, the authors say, the northern Indian Ocean, which is adjacent to highly populated regions, is not warming as quickly as the rest of the ocean, resulting in increased drought conditions that could hold repercussions for more than 2 billion people in South Asia. These conditions impact a range of industries and resources, from agriculture to freshwater availability......... Posted by: Tyler Permalink Source Pollutant Haze Heats The Arctic
The effect makes the Arctic 2 degrees to 3 degrees Fahrenheit warmer during polluted, cloudy episodes than it would be if the air was clean, concludes the study by Tim Garrett, an assistant professor of meteorology, and Chuanfeng Zhao, a doctoral student in meteorology. "The Arctic is warming very quickly, particularly compared with the rest of the world, due to the greenhouse effect caused by carbon dioxide from factories and cars," Garrett says. "Now we are finding there is another way pollution can warm up the Arctic. Particulate pollution from factories and cars can be transported long distances to the Arctic, where it changes clouds so that they become more effective blankets, trapping more heat and further aggravating climate warming." Arctic haze has been seen in the Arctic since the Industrial Revolution began about 1750. "Whalers and explorers noticed what looked like pollution and couldn't figure out where it was coming from," Garrett says. The Inuit (Eskimos) called it "poo-jok."........ Posted by: Tyler Permalink Source Importance Of Fungi In Arctic Nitrogen Cycle
It has long been known when soil nitrogen is in short supply, mycorrhizal fungi (those living symbiotically on the roots of plants) transfer nutrients to their host plants in exchange for plant sugars derived from photosynthesis, but the rates of transfer have never been quantified in the field. John and Erik Hobbie's study, reported in the April 2006 issue of the journal Ecology, quantifies the role. of mycorrhizal fungi in nitrogen cycling for the first time through measurements of the natural abundance of nitrogen isotopes in soils, mushrooms and plants. The scientists tested their technique using data from the Arctic LTER (Long Term Ecological Research) site near Toolik Lake, Alaska, in the northern foothills of the Brooks Range......... Posted by: Tyler Permalink Hurricane Linked To Long-term Mental Distress
The researchers, sociology doctoral student and lead author David Russell and professors John Taylor and Donald Lloyd, presented their findings at the 2006 annual meeting of the Southern Sociological Society held recently in New Orleans. Although the short-term mental health consequences of Hurricane Andrew have been documented, this study of adolescents is the first to show that it had long-term effects on mental health. "We found that people who experienced prior stressful events and who had pre-existing symptoms of psychological distress were more adversely affected by exposure to hurricane-related stressful events," Russell said. "Based on our findings, we believe intervention efforts should include assessments of the prior experiences and psychological well-being of disaster victims. Doing so will aid response workers in identifying those most at risk for developing post-disaster psychological problems". The findings suggest that the mental health consequences of Hurricane Katrina, which struck the Gulf Coast on Aug. 29, 2005, will be even greater. Although the storms were similar in strength, the human and economic costs associated with Katrina far exceeded those of Andrew. Deaths associated with Katrina were more than 50 times greater than those attributed to Andrew, and economic analysts predict that the total economic cost of Katrina will surpass $200 billion, which is more than five times the cost of Andrew......... Posted by: Tyler Permalink Source |
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Heart Mountain North of Cody, Wyoming
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