*Significant amount of carbon in land is leaking into streams and rivers, then to the atmosphere*
Rivers and streams in the United States are releasing substantially more carbon dioxide into the atmosphere than previously thought.
This according to researchers publishing their results in the current issue of the journal Nature Geoscience. (more…)
ANN ARBOR, Mich.— The solar wind sandblasts the surface of planet Mercury at its poles, according to new data from a University of Michigan instrument on board NASA’s MESSENGER spacecraft.
The sodium and oxygen particles the blistering solar wind kicks up are the primary components of Mercury’s wispy atmosphere, or “exosphere,” the new findings assert. Through interacting with the solar wind, they become charged in a mechanism that’s similar to the one that generates the Aurora Borealis on Earth. (more…)
The blanket of sea ice that floats on the Arctic Ocean appears to have reached its lowest extent for 2011, the second lowest recorded since satellites began measuring it in 1979, according to the University of Colorado Boulder’s National Snow and Ice Data Center.
The Arctic sea ice extent fell to 1.67 million square miles, or 4.33 million square kilometers on Sept. 9, 2011. This year’s minimum of 1.67 million square miles is more than 1 million square miles below the 1979-2000 monthly average extent for September — an area larger than Texas and California combined. (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…)
*New computer modeling study, led by a Berkeley Lab scientist, could help revise understanding of permafrost’s role in global warming*
Billions of tons of carbon trapped in high-latitude permafrost may be released into the atmosphere by the end of this century as the Earth’s climate changes, further accelerating global warming, a new computer modeling study indicates.
The study also found that soil in high-latitude regions could shift from being a sink to a source of carbon dioxide by the end of the 21st century as the soil warms in response to climate change. (more…)
A NASA-led research team has confirmed what Walt Disney told us all along: Earth really is a small world, after all.
Since Charles Darwin’s time, scientists have speculated that the solid Earth might be expanding or contracting. That was the prevailing belief, until scientists developed the theory of plate tectonics, which explained the large-scale motions of Earth’s lithosphere, or outermost shell. Even with the acceptance of plate tectonics half a century ago, some Earth and space scientists have continued to speculate on Earth’s possible expansion or contraction on various scientific grounds.
Now a new NASA study, published recently in Geophysical Research Letters, has essentially laid those speculations to rest. Using a cadre of space measurement tools and a new data calculation technique, the team detected no statistically significant expansion of the solid Earth. (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…)
*Melting ice sheets contributed much more to rising sea levels than thermal expansion of warming ocean waters during the Last Interglacial Period, a UA-led team of researchers has found. The results further suggest that ocean levels continue to rise long after warming of the atmosphere levels off.*
Thermal expansion of seawater contributed only slightly to rising sea levels compared to melting ice sheets during the Last Interglacial Period, a University of Arizona-led team of researchers has found.
The study combined paleoclimate records with computer simulations of atmosphere-ocean interactions and the team’s co-authored paper is accepted for publication in Geophysical Research Letters. (more…)
