Boulder scientists this summer will take part in a major NASA airborne science campaign aimed at better understanding the impacts of air pollution and weather patterns over a vast portion of North America.

The multimillion-dollar effort, called Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveyors, or SEAC4RS, is led by University of Colorado professor Brian Toon.

With help from 250 scientists, engineers, students and flight personnel from five NASA research centers, the National Center for Atmospheric Research, the National Oceanic and Atmospheric Administration and 15 universities, including CU, the project aims to look at Earth's atmosphere from top to bottom.

"These missions are how you do experiments in the atmosphere," said Toon, an atmospheric and oceanic sciences professor and veteran of 10 such NASA missions. "It's one thing to sit in an office and hypothesize, and it's another to go out into the atmosphere and see what is actually going on."

The research team will rely on a variety of scientific instruments aboard three aircraft: a NASA high-altitude ER-2; a Boulder-based Spec Inc. Learjet equipped with advanced sensors for measuring cloud properties; and a NASA DC-8 operating as a flying laboratory.

Toon said the mission's numerous goals include measuring the impacts of biogenic emissions -- or atmospheric emissions from plants and animals -- on the atmosphere over the southeastern U.S., as well as the atmospheric and climate change impact of smoke from large forest fires.


It will also focus on the transfer of air pollution and other substances carried from Earth's surface up into the atmosphere by storms like hurricanes and how those substances then interact with the ozone layer. Toon said the North American monsoon -- a weather pattern that forms near the American Southwest and then rotates clockwise into the Gulf of Mexico, across Central America and northern South America and back up the Pacific Coast -- also occurs during the study period.

"Both the hurricanes and this big circulation are full of all kinds of thunderstorms, and the thunderstorms are taking warm air from the ground and pushing it into the high atmosphere," Toon said. "We would like to know what hurricanes are pushing into the upper atmosphere and what the North American monsoon is pushing to the upper atmosphere."

Sebastian Schmidt, a research scientist for CU's Laboratory for Atmospheric and Space Physics, is participating in the mission, focusing on the combined effect of clouds and aerosols, such as fire smoke plumes and urban pollution, on solar radiation. He will take measurements from instruments aboard the high-altitude ER-2 aircraft as well as the DC-8, which can fly below or through an area of interest, to see how clouds and aerosol behave when in close proximity to each other.

While NASA satellites can measure the impacts of clouds and aerosols separately, they have trouble distinguishing between the two when they are in close proximity to one another. Schmidt's data will measure the accuracy of NASA satellites and help develop new techniques for gathering data about clouds and aerosols.

"The set of instruments that is going to be deployed on these aircraft ... have all of these capabilities that are not yet available in space," Schmidt said. "In a way, this is a pre-study for future satellite instruments, and the results that will come out of these experiments will have an impact on what instruments will be put up there."

Also working on the mission is associate CU chemistry and biochemistry professor Jose Jimenez, a fellow with the Cooperative Institute for Research in Environmental Sciences. He said the long-distance capabilities of the DC-8 aircraft will be beneficial in helping track smoke plumes from fires as they move across the continent.

"We consider ourselves to be very lucky to be able to work with this NASA team," he said.
