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 Global threat to primates concerns us all
19.01.2017 | Deutsches Primatenzentrum GmbH - Leibniz-Institut für Primatenforschung

nachricht Reducing household waste with less energy
18.01.2017 | FIZ Karlsruhe – Leibniz-Institut für Informationsinfrastruktur GmbH

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: Traffic jam in empty space

New success for Konstanz physicists in studying the quantum vacuum

An important step towards a completely new experimental access to quantum physics has been made at University of Konstanz. The team of scientists headed by...

Im Focus: How gut bacteria can make us ill

HZI researchers decipher infection mechanisms of Yersinia and immune responses of the host

Yersiniae cause severe intestinal infections. Studies using Yersinia pseudotuberculosis as a model organism aim to elucidate the infection mechanisms of these...

Im Focus: Interfacial Superconductivity: Magnetic and superconducting order revealed simultaneously

Researchers from the University of Hamburg in Germany, in collaboration with colleagues from the University of Aarhus in Denmark, have synthesized a new superconducting material by growing a few layers of an antiferromagnetic transition-metal chalcogenide on a bismuth-based topological insulator, both being non-superconducting materials.

While superconductivity and magnetism are generally believed to be mutually exclusive, surprisingly, in this new material, superconducting correlations...

Im Focus: Studying fundamental particles in materials

Laser-driving of semimetals allows creating novel quasiparticle states within condensed matter systems and switching between different states on ultrafast time scales

Studying properties of fundamental particles in condensed matter systems is a promising approach to quantum field theory. Quasiparticles offer the opportunity...

Im Focus: Designing Architecture with Solar Building Envelopes

Among the general public, solar thermal energy is currently associated with dark blue, rectangular collectors on building roofs. Technologies are needed for aesthetically high quality architecture which offer the architect more room for manoeuvre when it comes to low- and plus-energy buildings. With the “ArKol” project, researchers at Fraunhofer ISE together with partners are currently developing two façade collectors for solar thermal energy generation, which permit a high degree of design flexibility: a strip collector for opaque façade sections and a solar thermal blind for transparent sections. The current state of the two developments will be presented at the BAU 2017 trade fair.

As part of the “ArKol – development of architecturally highly integrated façade collectors with heat pipes” project, Fraunhofer ISE together with its partners...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Sustainable Water use in Agriculture in Eastern Europe and Central Asia

19.01.2017 | Event News

12V, 48V, high-voltage – trends in E/E automotive architecture

10.01.2017 | Event News

2nd Conference on Non-Textual Information on 10 and 11 May 2017 in Hannover

09.01.2017 | Event News

 
Latest News

Helmholtz International Fellow Award for Sarah Amalia Teichmann

20.01.2017 | Awards Funding

An innovative high-performance material: biofibers made from green lacewing silk

20.01.2017 | Materials Sciences

Ion treatments for cardiac arrhythmia — Non-invasive alternative to catheter-based surgery

20.01.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>