Scientists using one of the nation's newest and most capable research aircraft are launching a far-reaching field project this month to study plumes of airborne dust and pollutants that originate in Asia and journey to North America.
The plumes are among the largest such events on Earth, so great in scope that scientists believe they might affect clouds and weather across thousands of miles while interacting with the Sun's radiation and playing a role in global climate.
Known as PACDEX (Pacific Dust Experiment), the project will be led by scientists at the National Center for Atmospheric Research (NCAR) and the Scripps Institution of Oceanography. NCAR's main sponsor, the National Science Foundation (NSF), will provide most of the funding. The first mission will be launched in late April, depending on weather patterns in Asia. It will continue for two months.
To study the changes in the plumes as they move through the atmosphere from Japan to the western United States, the PACDEX team will deploy the NSF Gulfstream-V aircraft, which is operated and maintained by NCAR. This newly configured plane has a range of about 6,000 miles and can cruise from just a few hundred feet above Earth's surface to over 50,000 feet. These features enable scientists to study the plumes across thousands of miles and at different levels of the atmosphere.
"Aerosol pollutants, such as those to be studied in PACDEX, account for the largest uncertainties in climate forcing," said Jay Fein, program director in NSF's Division of Atmospheric Sciences, which funded the experiment. "PACDEX is addressing this challenging and societally relevant science question."
While many particles in the plumes, such as sulfates, cool the planet by blocking solar radiation from reaching Earth, some particles such as black carbon absorb sunlight as well and therefore may amplify the effects of global warming. PACDEX will help scientists refine computer models
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Contact: Cheryl Dybas
cdybas@nsf.gov
703-292-7734
National Science Foundation
19-Apr-2007