A hemispherewide phenomenon – and not just regional forces – has caused record-breaking amounts of freshwater to accumulate in the Arctic’s Beaufort Sea.
Frigid freshwater flowing into the Arctic Ocean from three of Russia’s mighty rivers was diverted hundreds of miles to a completely different part of the ocean in response to a decades-long shift in atmospheric pressure associated with the phenomenon called the Arctic Oscillation, according to findings published in the Jan. 5 issue of Nature. (more…)
*Berkeley Lab scientists part of team that analyzed 19 state-of-the-art climate models.*
While the worst drought since the Dust Bowl of the 1930s grips Oklahoma and Texas, scientists are warning that what we consider severe drought conditions in North America today may be normal for the continent by the mid-21st century, due to a warming planet.
A team of scientists from the Lawrence Berkeley National Laboratory (Berkeley Lab), Lawrence Livermore National Laboratory (LLNL), and the National Oceanic and Atmospheric Administration (NOAA) came to this conclusion after analyzing 19 different state-of-the-art climate models. Looking at the balance between precipitation and evapotranspiration—the movement of water from soil to air—they found that no matter how rainfall patterns change over the next 100 years, a warming planet leads to drought. Their results were published in the December 2011 issue of the American Meteorological Society’s Journal of Hydrometerology. (more…)
*Charles P. Sonett, the first head of the UA’s department of planetary sciences, died at the age of 87. Sonett was involved in spacecraft missions that dramatically advanced our understanding of the solar system and beyond, including the Pioneer Program, the Explorer Program and the Apollo Program.*
Charles “Chuck” P. Sonett, a founding faculty member and the first department head of the University of Arizona’s department of planetary sciences, died on Sept. 30. He was 87.
As a space exploration pioneer, Sonett was involved in numerous spacecraft programs, including the Pioneer Program, the Explorer Program and the Apollo Program – missions that dramatically advanced our understanding of the solar system, its planets and moons and beyond. (more…)
Washington, DC — Scientists have long debated about the impact on global climate of water evaporated from vegetation. New research from Carnegie’s Global Ecology department concludes that evaporated water helps cool the earth as a whole, not just the local area of evaporation, demonstrating that evaporation of water from trees and lakes could have a cooling effect on the entire atmosphere. These findings, published September 14 in Environmental Research Letters, have major implications for land-use decision making.
Evaporative cooling is the process by which a local area is cooled by the energy used in the evaporation process, energy that would have otherwise heated the area’s surface. It is well known that the paving over of urban areas and the clearing of forests can contribute to local warming by decreasing local evaporative cooling, but it was not understood whether this decreased evaporation would also contribute to global warming (more…)
GAINESVILLE, Fla. — After a 10,000-year absence, wildfires have returned to the Arctic tundra, and a University of Florida study shows that their impact could extend far beyond the areas blackened by flames.
In a study published in the July 28 issue of the journal Nature, UF ecologist Michelle Mack and a team of scientists including fellow UF ecologist Ted Schuur quantified the amount of soil-bound carbon released into the atmosphere in the 2007 Anaktuvuk River fire, which covered more than 400 square miles on the North Slope of Alaska’s Brooks Range. The 2.1 million metric tons of carbon released in the fire — roughly twice the amount of greenhouse gases put out by the city of Miami in a year — is significant enough to suggest that Arctic fires could impact the global climate, said Mack, an associate professor of ecosystem ecology in UF’s department of biology. (more…)
*Evidence that early Antarctic Circumpolar Current development affected global climate*
Thirty-eight million years ago, tropical jungles thrived in what are now the cornfields of the American Midwest and furry marsupials wandered temperate forests in what is now the frozen Antarctic.
The temperature differences of that era, known as the late Eocene, between the equator and Antarctica were half what they are today. (more…)
*Increased Agulhas “leakage” significant player in global climate variability*
The Agulhas Current which runs along the east coast of Africa may not be as well known as its counterpart in the Atlantic, the Gulf Stream. But now researchers are taking a closer look at this current and its “leakage” from the Indian Ocean into the Atlantic Ocean–and what that may mean for climate change.
In results of a study published in this week’s issue of the journal Nature, a team of scientists led by University of Miami Rosenstiel School of Marine & Atmospheric Science Oceanographer Lisa Beal, suggests that Agulhas leakage could be a significant player in global climate variability. (more…)
WASHINGTON — Researchers looking at corals in the western tropical Pacific Ocean have found signs of a profound shift in the depth where warm surface water and colder deeper water meet—a shift predicted by computer models of global warming.
The finding is the first physical evidence supporting what climate modelers have been predicting as the effects of global climate change on the subsurface ocean circulation. (more…)
