Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Scientists Reveal Soot’s Role in Climate Change

18.08.2008
Soot, or aerosols, can have both heating and cooling effects on clouds. Weizmann Institute scientists and colleagues have now developed a model of this complex relationship, showing when aerosols rising into the clouds will result in heating or cooling. Their findings may help convey the true climatic consequences of fires and industrial fuels.

Tons of soot are released into the air annually as forest fires rage from California to the Amazon to Siberia and Indonesia.

Climate scientists have generally assumed that the main effect of smoke on climate is cooling, as the floating particles can reflect some solar energy back to space as well as increasing cloud size and lifespan. But new research by scientists at the Weizmann Institute of Science; the University of Maryland, Baltimore County (UMBC); and NASA may cause them to rethink soot’s role in shaping the Earth’s climate.

Airborne particles such as soot – known collectively as aerosols – rise into the atmosphere where they interact with clouds. Understanding what happens when the two meet is extremely complicated, in part because clouds are highly dynamic systems that both reflect the sun’s energy back into space, cooling the upper atmosphere, and trap heat underneath, warming the lower atmosphere and the Earth’s surface. Aerosols, in turn, can have both heating and cooling effects on clouds. On the one hand, water droplets form around the aerosol particles, which may extend the cloud cover. On the other hand, particles, especially soot, absorb the sun’s radiation, stabilizing the atmosphere and thus reducing cloud formation.

Dr. Ilan Koren and Hila Afargan of the Weizmann Institute’s Environmental Sciences and Energy Research Department, together with colleagues from UMBC and NASA’s Goddard Space Flight Center in Maryland, have, for the first time, developed an analytical model that puts all of these factors together to show when aerosols rising into the clouds will heat things up and when they will cool them off. The scientists tested their model on data from the Amazon, finding it reflected the true situation on the ground so accurately they could rule out the possibility that random changes in cloud cover – rather than aerosols from burning forests – were at work.

Their findings, which appear in the August 15, 2008 issue of Science, reveal that adding small quantities of aerosols into a clean environment can indeed produce a net cooling effect. As more and more particles enter the cloud layer, however, the effect progressively switches from cooling to heating mode. The researchers also found that the extent of the original cloud cover is important. A completely overcast sky prevents the sun’s rays from reaching the aerosols, so the result may be additional cooling of the atmosphere and the Earth’s surface. But the larger the ratio of open sky to clouds, the more aerosol particles absorb radiation, thus hastening the heating of the remaining cloud cover, reducing cloud cover, and heating the system.

An accurate model of the intricate relationship between clouds and aerosols has been a key missing piece in the picture of human-induced climate change. The scientists believe their findings may help both climate modelers and policy makers to understand the true climatic consequences of burning trees or sooty industrial fuels.

Dr. Ilan Koren’s research is supported by the Sussman Family Center for the Study of Environmental Sciences; the Fusfeld Research Fund; and the Samuel M. Soref and Helene K. Soref Foundation.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

Jennifer Manning | Newswise Science News
Further information:
http://www.acwis.org

More articles from Ecology, The Environment and Conservation:

nachricht Scientists team up on study to save endangered African penguins
16.11.2017 | Florida Atlantic University

nachricht Climate change: Urban trees are growing faster worldwide
13.11.2017 | Technische Universität München

All articles from Ecology, The Environment and Conservation >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>