Using satellite imaging and measurements from research aircraft, scientists this summer hope to gain a clearer understanding of significant changes in ecosystems and air quality taking place in central and southern Africa following major social, economic and political shifts in recent years.
A state-of-the-art University of Washington research aircraft will be a key element in the Southern Africa Regional Science Initiative (SAFARI 2000) campaign, taking low-altitude readings that will be correlated to data from a high-flying NASA aircraft and from a satellite that is part of NASA's Earth Observing System.
Equipment on board the UW aircraft, Husky One, will measure concentrations of various gases, including carbon dioxide, carbon monoxide, ozone, nitrogen oxides and sulfuric oxide, said atmospheric sciences professor Peter Hobbs, who heads the UW's Cloud and Aerosol Research Group. The aircraft will fly below 10,000 feet, measuring pollutants in a subcontinent-sized plume that starts in southern Africa and travels in a counterclockwise rotation thousands of miles to the east, north and finally west, out over the southern Atlantic Ocean.
Trace gases and suspended particles, or aerosols, are pumped into that rotation from three primary sources: fossil-fuel burning and other industrial activities; agricultural fires, wildfires and domestic hearth fires; and natural processes.
In recent years the region not only has faced increased fossil-fuel emissions but also has experienced some of the most extensive biomass burning in the world, most of it linked to savanna burning, firewood consumption and agricultural practices.
"The whole area of southern Africa is going through tremendous change," Hobbs said.
To help understand the ramifications of that change, he and other researchers aboard Husky One will examine pollution at or near its sources in the counterclockwise rotation, then study how the emissions are modified physically and chemically as they age and move farther from their sources.
"It's the aged pollutants that have the most affect on regional and global climate, not local pollutants," Hobbs said.
Husky One, a Convair 580 turboprop, will be outfitted with a variety of special equipment for the SAFARI 2000 campaign. Researchers aboard the aircraft will come from several institutions, including NASA, the University of Montana and Brigham Young University. The aircraft can accommodate about a dozen researchers.
"When fully instrumented like this, it's probably the best equipped plane in the world for studying aerosols, gases, clouds and radiation," Hobbs said.
About 15 UW faculty, staff and graduate students will accompany Hobbs on the SAFARI campaign, which runs from Aug. 13 through Sept. 22. Typical research flights are about five hours, Hobbs said. The aircraft initially will be based in Pietersburg, South Africa, then later in the campaign will fly out of Lusaka, Zambia, and Walvis Bay, Namibia.
"This will allow us to characterize the subcontinental plume at three major points," Hobbs said.
The UW's Cloud and Aerosol Research Group is among the world's largest teams studying atmospheric aerosols and clouds. The group was the first to take airborne measurements from the mammoth ash cloud following the violent eruption of Mount St. Helens in 1980, and also studied the effects of huge oilfield fires in Kuwait during the Gulf War in 1991.
Husky One, commissioned in 1998 to replace an older Convair, already has been flown for the Surface Heat Budget of the Arctic Ocean (SHEBA) project and used as a means of verifying satellite data measuring clouds in the atmosphere over the Marshall Islands in the South Pacific Ocean. Next winter it will be used to study storms, clouds and precipitation in the Pacific Northwest.
For more information, contact Hobbs at 206-543-6027 or phobbs@atmos.washington.edu
Cloud and Research Group home page: http://cargsun2.atmos.washington.edu
A print-quality photograph of the Husky One aircraft being pushed out of its hangar may be downloaded through this release at http://www.washington.edu/newsroom/news