A new study reorders the timing and reveals the climate impact of nearly 300 major volcanic eruptions worldwide, dating back to the early Roman period.
The analysis, published July 8 in the journal Nature, resolves longstanding inconsistencies between historic atmospheric sulfate data taken from ice cores and corresponding temperature data derived from tree rings and other sources. The new chronology of volcanic eruptions reveals that such eruptions had a significant and repeated impact on global climate.(more…)
With a $3.9 million grant from the U.S. Department of Energy, a UA-led international collaboration studies how microbes release greenhouse gases as they gain access to nutrients in the soil thawing under the influence of warmer global temperatures.
The U.S. Department of Energy has awarded $3.9 million to an international collaboration led by University of Arizona ecologists Scott Saleska and Virginia Rich to study how microbes release greenhouse gases as they access nutrients in thawing permafrost soils under the influence of a warmer climate. (more…)
Using an innovative satellite technique, NASA scientists have determined that a previously unmapped type of wildfire in the Amazon rainforest is responsible for destroying several times more forest than has been lost through deforestation in recent years.
In the southern Amazon rainforest, fires below the forest treetops, or “understory fires,” have been hidden from view from NASA satellites that detect actively burning fires. The new method has now led to the first regional estimate of understory fire damages across the southern Amazon. (more…)
Antarctica’s topography began changing from flat to fjord-filled starting about 34 million years ago, according to a new report from a University of Arizona-led team of geoscientists.
Knowing when Antarctica’s topography started shifting from a flat landscape to one with glaciers, fjords and mountains is important for modeling how the Antarctic ice sheet affects global climate and sea-level rise. (more…)
EAST LANSING, Mich. — Warmer oceans in the future could significantly alter populations of phytoplankton, tiny organisms that could have a major impact on climate change.
In the current issue of Science Express, Michigan State University researchers show that by the end of the 21st century, warmer oceans will cause populations of these marine microorganisms to thrive near the poles and may shrink in equatorial waters. Since phytoplankton play a key role in the food chain and the world’s cycles of carbon, nitrogen, phosphorous and other elements, a drastic drop could have measurable consequences. (more…)
UD’s Wang contributes invited paper on cloud microphysics
Lian-Ping Wang, professor of mechanical engineering and joint professor of physical ocean science and engineering at the University of Delaware, recently published an invited critical review paper in the 2013 volume of the Annual Review of Fluid Mechanics, a high impact journal for the fluid mechanics community.
Co-authored with Wojciech Grabowski, a senior scientist from the National Center for Atmospheric Research (NCAR), the paper, titled “Growth of Cloud Droplets in a Turbulent Environment,” addresses a classic cloud physics problem of how cloud turbulence affects the growth of tiny cloud droplets. (more…)
Scientists from the Woods Hole Oceanographic Institution (WHOI) have conducted a new study to measure levels of carbon at various depths in the Arctic Ocean. The study, recently published in the journal Biogeosciences, provides data that will help researchers better understand the Arctic Ocean’s carbon cycle—the pathway through which carbon enters and is used by the marine ecosystem. It will also offer an important point of reference for determining how those levels of carbon change over time, and how the ecosystem responds to rising global temperatures.
“Carbon is the currency of life. Where carbon is coming from, which organisms are using it, how they’re giving off carbon themselves—these things say a lot about how an ocean ecosystem works,” says David Griffith, the lead author on the study.“If warming temperatures perturb the Arctic Ocean, the way that carbon cycles through that system may change.” (more…)
Earth’s clouds got a little lower — about one percent on average — during the first decade of this century, finds a new NASA-funded university study based on NASA satellite data. The results have potential implications for future global climate.
Scientists at the University of Auckland in New Zealand analyzed the first 10 years of global cloud-top height measurements (from March 2000 to February 2010) from the Multi-angle Imaging SpectroRadiometer (MISR) instrument on NASA’s Terra spacecraft. The study, published recently in the journal Geophysical Research Letters, revealed an overall trend of decreasing cloud height. Global average cloud height declined by around one percent over the decade, or by around 100 to 130 feet (30 to 40 meters). Most of the reduction was due to fewer clouds occurring at very high altitudes. (more…)
