Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

National Oceanic and Atmospheric Administration University of Colorado Joint Release

22.07.2008
The Arctic may get some temporary relief from global warming if the annual North American wildfire season intensifies, according to a new study.

Smoke transported to the Arctic from northern forest fires may cool the surface for several weeks to months at a time, according to the most detailed analysis yet of how smoke influences the Arctic climate relative to the amount of snow and ice cover.

"Smoke in the atmosphere temporarily reduces the amount of solar radiation reaching the surface. This transitory effect could partly offset some of the warming caused by the buildup of greenhouse gases and other pollutants," says lead author Robert Stone of the University of Colorado and NOAA Cooperative Institute for Research in Environmental Sciences (CIRES).

He and his colleagues report their findings tomorrow, 22 July 2008, in the Journal of Geophysical Research-Atmospheres, a publication of the American Geophysical Union (AGU).

How much solar energy is prevented from reaching the surface depends on the smoke's opacity, the elevation of the sun above the horizon, and the brightness of the surface, according to the study.

Stone and his colleagues analyzed the short-term climate impact of numerous wildfires that swept through Alaska and western Canada in 2004. That summer, fires burned a record 26,000 square kilometers (10,000 square miles) of Alaska's interior and another 31,000 square kilometers (12,000 square miles) in western Canada. A NOAA climate observatory near Barrow, Alaska, provided the data for the study.

Smoke observed at Barrow was so thick that, at times, visibility dropped to just over 1.6 kilometers (1 mile). The aerosol optical depth (AOD), a measure of the total absorption and scattering of solar radiation by smoke particles, rose a hundredfold from typical summer values.

Smoke in the atmosphere tends to cool the snow-free tundra while warming the smoke layer itself, the authors found. Smoke has an even greater cooling effect over the darker, ice-free ocean and less over bright snow.

"The heating of the smoke layer and cooling of the surface can lead to increased atmospheric stability, which in turn may keep clouds from forming," said Stone. "We think that this influence of smoke aerosol on clouds further affects the balance of radiation reaching the surface in the Arctic."

Research observatories as far away as Greenland and the Svalbard archipelago north of Norway also recorded elevated AOD values over several weeks during the 2004 summer, suggesting that the climate footprint of the North American wildfires was far-reaching.

Smoke from the same fires also was observed as far south as the Gulf of Mexico.

To conduct their analysis, Stone and colleagues looked at how a range of smoky conditions might change the amount of solar radiation reaching the Earth's surface. Models showed that the cooling caused by future forest fires would depend on the severity of the fire season and on the geographic dispersion of smoke.

The authors cautioned, however, that the full climate impact of Arctic aerosols, including smoke particles, is still not entirely clear.

For one thing, smoke particles captured within clouds or deposited on snow may change the brightness of these objects, further affecting the amount of solar radiation absorbed by the surface.

Also, aerosols such as smoke affect the absorption and scattering not only of solar radiation, but also of longwave or thermal radiation within the atmosphere. The impact of aerosols on longwave radiation, which dominates at night and during the long, dark winter season in the Arctic, has yet to be quantified.

Peter Weiss | American Geophysical Union
Further information:
http://www.agu.org/

More articles from Ecology, The Environment and Conservation:

nachricht Upcycling 'fast fashion' to reduce waste and pollution
03.04.2017 | American Chemical Society

nachricht Litter is present throughout the world’s oceans: 1,220 species affected
27.03.2017 | Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung

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: Making lightweight construction suitable for series production

More and more automobile companies are focusing on body parts made of carbon fiber reinforced plastics (CFRP). However, manufacturing and repair costs must be further reduced in order to make CFRP more economical in use. Together with the Volkswagen AG and five other partners in the project HolQueSt 3D, the Laser Zentrum Hannover e.V. (LZH) has developed laser processes for the automatic trimming, drilling and repair of three-dimensional components.

Automated manufacturing processes are the basis for ultimately establishing the series production of CFRP components. In the project HolQueSt 3D, the LZH has...

Im Focus: Wonder material? Novel nanotube structure strengthens thin films for flexible electronics

Reflecting the structure of composites found in nature and the ancient world, researchers at the University of Illinois at Urbana-Champaign have synthesized thin carbon nanotube (CNT) textiles that exhibit both high electrical conductivity and a level of toughness that is about fifty times higher than copper films, currently used in electronics.

"The structural robustness of thin metal films has significant importance for the reliable operation of smart skin and flexible electronics including...

Im Focus: Deep inside Galaxy M87

The nearby, giant radio galaxy M87 hosts a supermassive black hole (BH) and is well-known for its bright jet dominating the spectrum over ten orders of magnitude in frequency. Due to its proximity, jet prominence, and the large black hole mass, M87 is the best laboratory for investigating the formation, acceleration, and collimation of relativistic jets. A research team led by Silke Britzen from the Max Planck Institute for Radio Astronomy in Bonn, Germany, has found strong indication for turbulent processes connecting the accretion disk and the jet of that galaxy providing insights into the longstanding problem of the origin of astrophysical jets.

Supermassive black holes form some of the most enigmatic phenomena in astrophysics. Their enormous energy output is supposed to be generated by the...

Im Focus: A Quantum Low Pass for Photons

Physicists in Garching observe novel quantum effect that limits the number of emitted photons.

The probability to find a certain number of photons inside a laser pulse usually corresponds to a classical distribution of independent events, the so-called...

Im Focus: Microprocessors based on a layer of just three atoms

Microprocessors based on atomically thin materials hold the promise of the evolution of traditional processors as well as new applications in the field of flexible electronics. Now, a TU Wien research team led by Thomas Müller has made a breakthrough in this field as part of an ongoing research project.

Two-dimensional materials, or 2D materials for short, are extremely versatile, although – or often more precisely because – they are made up of just one or a...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Fighting drug resistant tuberculosis – InfectoGnostics meets MYCO-NET² partners in Peru

28.04.2017 | Event News

Expert meeting “Health Business Connect” will connect international medical technology companies

20.04.2017 | Event News

Wenn der Computer das Gehirn austrickst

18.04.2017 | Event News

 
Latest News

Wireless power can drive tiny electronic devices in the GI tract

28.04.2017 | Medical Engineering

Ice cave in Transylvania yields window into region's past

28.04.2017 | Earth Sciences

Nose2Brain – Better Therapy for Multiple Sclerosis

28.04.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>