Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Transported Black Carbon a Significant Player in Pacific Ocean Climate

15.03.2007
Soot and other particulate pollution from Asian sources make up more than 75 percent of black carbon transported at high altitudes, according to a Scripps Institution of Oceanography, UC San Diego-led study

More than three-quarters of the particulate pollution known as black carbon transported at high altitudes over the West Coast during spring is from Asian sources, according to a research team led by Professor V. Ramanathan at Scripps Institution of Oceanography, UC San Diego.

Though the transported black carbon, most of which is soot, is an extremely small component of air pollution at land surface levels, the phenomenon has a significant heating effect on the atmosphere at altitudes above two kilometers (6,562 feet).

As the soot heats the atmosphere, however, it also dims the surface of the ocean by absorbing solar radiation, said Ramanathan, a climate scientist at Scripps, and Odelle Hadley, a graduate student at the Center for Atmospheric Sciences at Scripps. The two are lead authors of a research paper appearing in the March 14 issue of the Journal of Geophysical Research.

The dual effect carries consequences for the Pacific Ocean region that drives much of Earth's climate.

"That's the primary concern we have with these aerosols," said Hadley. "They can really affect global climate."

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

The researchers found that transported black carbon from Asian sources is equal to 77 percent of North American black carbon emissions in the troposphere during the spring. In a follow-on study funded by the California Energy Commission (CEC), Hadley, Ramanathan and fellow Scripps climate scientist Craig Corrigan are now studying how much carbon might be incorporated into precipitation and what the effects on melt rates of Sierra Nevada snow pack could be.

The measure of high black carbon concentration from Asian sources "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. "Fortunately, we have already started to address this issue with Scripps and more studies are being planned."

The researchers compared rarely available in-flight data collected during the spring 2004 Cloud Indirect Effects Experiment (CIFEX), a component of which was a series of atmospheric meteorological measurements made during flights originating in Eureka, Calif. The team combined that information with data from 30 West Coast meteorological stations and compared it with computer predictions made by the Chemical Weather Forecast System (CFORS).

Transport of Asian black carbon, particulate pollution generated by automobile exhaust, agricultural burning and other sources, is heaviest in spring when cold Arctic fronts dip to lower latitudes and loft warmer air to higher levels in the atmosphere. It is part of a worldwide transport of aerosols that sees them remain aloft at high altitudes for up to two weeks.

Black carbon concentrations diminish as they move farther away from their sources in cities and farmlands in countries such as China and India. However, over the Pacific Ocean, the particles are in sufficient concentration to have a heating effect on the upper atmosphere, a prediction based on output from other computer models besides CFORS. At the same time, the radiation-absorbing particles dim skies at the surface.

On a regional level, that amount of heating, or positive radiative forcing, the black carbon causes in the skies over the Pacific is about 40 percent of the forcing that has been 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.

"It was a major surprise," said Ramanathan, Hadley's adviser at Scripps. "When we came up with the preliminary results, we had to check it and recheck it."

Results from Hadley's study of black carbon's snow pack effects are expected by the end of this year.

Authors of the Journal of Geophysical Research article besides Hadley and Ramanathan include Corrigan, Greg Roberts and Guillaume Mauger at Scripps Oceanography and Gregory Carmichael and Youhua Tang of the University of Iowa.

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

Robert Monroe | EurekAlert!
Further information:
http://www.ucsd.edu
http://scrippsnews.ucsd.edu/article_detail.cfm?article_num=777

All articles from Earth Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Unraveling the nature of 'whistlers' from space in the lab

A new study sheds light on how ultralow frequency radio waves and plasmas interact

Scientists at the University of California, Los Angeles present new research on a curious cosmic phenomenon known as "whistlers" -- very low frequency packets...

Im Focus: New interactive machine learning tool makes car designs more aerodynamic

Scientists develop first tool to use machine learning methods to compute flow around interactively designable 3D objects. Tool will be presented at this year’s prestigious SIGGRAPH conference.

When engineers or designers want to test the aerodynamic properties of the newly designed shape of a car, airplane, or other object, they would normally model...

Im Focus: Robots as 'pump attendants': TU Graz develops robot-controlled rapid charging system for e-vehicles

Researchers from TU Graz and their industry partners have unveiled a world first: the prototype of a robot-controlled, high-speed combined charging system (CCS) for electric vehicles that enables series charging of cars in various parking positions.

Global demand for electric vehicles is forecast to rise sharply: by 2025, the number of new vehicle registrations is expected to reach 25 million per year....

Im Focus: The “TRiC” to folding actin

Proteins must be folded correctly to fulfill their molecular functions in cells. Molecular assistants called chaperones help proteins exploit their inbuilt folding potential and reach the correct three-dimensional structure. Researchers at the Max Planck Institute of Biochemistry (MPIB) have demonstrated that actin, the most abundant protein in higher developed cells, does not have the inbuilt potential to fold and instead requires special assistance to fold into its active state. The chaperone TRiC uses a previously undescribed mechanism to perform actin folding. The study was recently published in the journal Cell.

Actin is the most abundant protein in highly developed cells and has diverse functions in processes like cell stabilization, cell division and muscle...

Im Focus: Lining up surprising behaviors of superconductor with one of the world's strongest magnets

Scientists have discovered that the electrical resistance of a copper-oxide compound depends on the magnetic field in a very unusual way -- a finding that could help direct the search for materials that can perfectly conduct electricity at room temperatur

What happens when really powerful magnets--capable of producing magnetic fields nearly two million times stronger than Earth's--are applied to materials that...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Within reach of the Universe

08.08.2018 | Event News

A journey through the history of microscopy – new exhibition opens at the MDC

27.07.2018 | Event News

2018 Work Research Conference

25.07.2018 | Event News

 
Latest News

Staying in Shape

16.08.2018 | Life Sciences

Diving robots find Antarctic seas exhale surprising amounts of carbon dioxide in winter

16.08.2018 | Earth Sciences

Protein droplets keep neurons at the ready and immune system in balance

16.08.2018 | Life Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>