Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Sun-warmed air pollution flows east from Asia

15.03.2007
Most of the atmosphere-warming soot transported at high altitudes over the West Coast in spring comes from Asia, a new study estimates. That continent generates more than 75 percent of the high-flying contamination, which is a type of particulate pollution known as black carbon.

By absorbing sunlight, black-carbon particles heat the upper atmosphere while also reducing radiation at the surface. The new data indicates that the warming is winning out.

"The soot heating of the atmosphere exceeds the surface dimming and, as a result, the long-range, transported soot amplifies the global warming due to increase in carbon dioxide," says Professor V. Ramanathan at the Scripps Institution of Oceanography, UC San Diego. He and Scripps graduate student Odelle Hadley led the study, published online today in the Journal of Geophysical Research (Atmospheres). Other scientists at Scripps and the University of Iowa, Iowa City, also contributed to the study.

The black carbon transported from Asia in spring equals 77 percent of the black carbon emitted into the troposphere from North America during that season, the team also finds. The researchers used computer simulations and measurements of pollution taken in March and April of 2004 at the surface and at various elevations. Mostly soot, black carbon comes from automobile exhaust, agricultural burning and other sources.

Although the transported black-carbon pollution is an extremely small component of air pollution at land surface levels, it has a significant heating effect on the atmosphere at altitudes above two kilometers (7,000 feet). The particles influence the Pacific Ocean region, which drives much of Earth’s climate. "That’s the primary concern we have with these aerosols," said Hadley. "They can really affect global climate."

In a follow-on study funded by the California Energy Commission (CEC), Hadley, Ramanathan, and fellow Scripps climate scientist Craig Corrigan--who is also a coauthor on the black-carbon transport study--are now investigating how much carbon might be incorporated into precipitation. The study will also examine potential consequences for melt rates of snowpack in California’s Sierra Nevada mountains. Results from that study are expected by the end of this year.

The newly reported measure of black-carbon influx from Asia "is a startling finding by itself, but its potential importance is magnified by the fact that black carbon is believed to have a disproportional impact on regional climate," said Guido Franco, technical lead for climate-change research at the CEC’s Public Interest Energy Research (PIER) program.

The black-carbon investigators compared predictions from a computer model called the Chemical Weather Forecast System (CFORS) to rarely available, in-flight data collected over the Eastern Pacific Ocean and to surface data from 30 West Coast meteorological stations.

Transport of Asian black carbon peaks in the spring when cold Arctic fronts dip to lower latitudes and loft warmer air to higher levels in the atmosphere. The eastward flow of the contaminants is part of a worldwide transport of aerosols, which remain aloft at high altitudes for up to two weeks.

Black carbon concentrations diminish as the pollution moves farther away from its sources in cities and farmlands in countries like China and India. However, over the Pacific Ocean, the particles are in sufficient concentration to have a warming effect on the upper atmosphere of between 2.04 and 2.55 watts per square meter, a prediction based on output from other computer models besides CFORS. By contrast, the black-carbon-induced dimming at the surface amounts to only -1.45 to -1.47 watts per square meter.

On a regional level, the amount of warming, or positive radiative forcing, the black carbon causes in the skies over the Pacific is about 40 percent of that attributed to the carbon dioxide increase of the last century, said Ramanathan. It likely has measurable effects on a variety of other physical and biological conditions in the areas of the Pacific over which the particulate pollution passes.

"We have to find out if this amplification is just restricted to spring time or is happening through out the year," Ramanathan says.

Scripps Oceanography researchers Greg Roberts and Guillaume Mauger, and Iowa’s Gregory Carmichael and Youhua Tang also took part in the study.

The National Science Foundation, the National Oceanic and Atmospheric Administration (NOAA), and the California Energy Commission funded the work.

Peter Weiss | AGU
Further information:
http://www.agu.org

More articles from Earth Sciences:

nachricht Sediment from Himalayas may have made 2004 Indian Ocean earthquake more severe
26.05.2017 | Oregon State University

nachricht Devils Hole: Ancient Traces of Climate History
24.05.2017 | Universität Innsbruck

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can the immune system be boosted against Staphylococcus aureus by delivery of messenger RNA?

Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.

Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....

Im Focus: A quantum walk of photons

Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.

The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....

Im Focus: Turmoil in sluggish electrons’ existence

An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.

We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...

Im Focus: Wafer-thin Magnetic Materials Developed for Future Quantum Technologies

Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.

Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...

Im Focus: World's thinnest hologram paves path to new 3-D world

Nano-hologram paves way for integration of 3-D holography into everyday electronics

An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Marine Conservation: IASS Contributes to UN Ocean Conference in New York on 5-9 June

24.05.2017 | Event News

AWK Aachen Machine Tool Colloquium 2017: Internet of Production for Agile Enterprises

23.05.2017 | Event News

Dortmund MST Conference presents Individualized Healthcare Solutions with micro and nanotechnology

22.05.2017 | Event News

 
Latest News

How herpesviruses win the footrace against the immune system

26.05.2017 | Life Sciences

Water forms 'spine of hydration' around DNA, group finds

26.05.2017 | Life Sciences

First Juno science results supported by University of Leicester's Jupiter 'forecast'

26.05.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>