SEAC4RS (pronounced "seekers") stands for?take a deep breath?the Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys. The project is described as NASA's most "complex airborne science campaign of the year," and campaign leader Brian Toon, a professor of atmospheric and oceanic sciences at University of Colorado-Boulder, is at the helm.
"It'll be exciting to get into the field and see what opportunities occur," Toon tells PopMech. "We have a lot of instruments here, so there's a high probability of discovering something new and interesting."
Toon, along with about 250 scientists, flight personnel, engineers, and students from 15 different universities will travel to Houston for the project and will operate out of NASA's Ellington Field. Planes outfitted with climate-gauging sensors will fly missions every other day from Aug.7 to the end of September. The project's primary goal is studying the atmospheric affects of emissions, both natural and man-made.
"In summertime across the United States, emissions from large seasonal fires, metropolitan areas, and vegetation are moved upward by thunderstorms and the North American Monsoon," Toon says. "When these chemicals get into the stratosphere they can affect the whole earth."
In Search of a Monsoon
The beginnings of SEAC4RS extend to the 1990s. NASA originally selected Thailand and Southeast Asia as the best location for SEAC4RS because of the perfect coalescence of emissions, biomass burning, and the Asian Monsoon. The mission was scheduled for summer 2012, but confusion about the project's purpose between the Thai government and NASA led to unfounded suspicions of possible espionage.
"Every rumor you could think of about what was happening occurred," Toon says. "We just couldn't get the people's permission in time to figure out the logistics for something like this."
The canceled program shifted its gaze to the southern United States and the North American Monsoon, an anticyclone which circles clockwise down the Gulf of Mexico, cuts across the Central America, and travels up the Pacific coast. "That's one of two areas where a lot of water is moving upward into the stratosphere," Toon says.
Flying Labs
Science this sophisticated needs a little more than weather balloons, program manager Hal Maring says. "The real driver here is the science. So we use the aircraft that most appropriately gives us the kind of sampling we need."
NASA will be flying a DC-8 passenger aircraft converted into a flying laboratory, complete with 26 sensors; an ER-2, the scientific cousin to the U-2 spy plane; and a Learjet from SPEC, Inc., outfitted to capture detailed cloud measurements. Jos?-Luis Jim?nez, a professor at CU-Boulder and participant in the SEAC4RS project, says that if you want to picture these flying labs, imagine a passenger plane with all the seats ripped out and replaced with scientific equipment. Instead of a packed-like-sardines coach-class seats, there are computer displays and crates of science equipment to fill the sides, with a narrow path between. Instruments and sensors poke outside plane fuselage like strange antennae.
These aircraft will work in conjunction with NASA satellites, as well as ground instruments, to get to most detailed atmospheric images possible while also improving NASA's satellite capabilities. The DC-8 and ER-2 fly only 8 hours every other day, so on off-days, flight planning will create more precision and less guesswork. "We will look at the science we learned from previous flights and try to figure out the best way to use the plane the next day," Toon says.
Aerosols
A lot of this science depends on the aerosol, a tiny particle in the atmosphere that can obscure visibility and cause climate change. Within the last decade, these particles have been discovered to be much more complex, sometimes with tens of thousands of compounds in them, Toon says. Understanding these particles, as well as organic gases, and how they interact with the atmosphere is what Toon hopes to find out. "Every cloud droplet forms on an aerosol particle, so if people make more aerosol particles, it's going to affect the number of drops in clouds," Toon says. "They change the properties of the clouds."
Despite the advanced gadgetry and an overwhelming workforce, Maring describes SEAC4RS research as pretty basic. But understanding how the atmosphere reacts to emissions can indirectly improve how scientists are able to predict air quality, and could provide a knowledge boost in unexpected places. "We'll learn about how efficiently these convective systems move material from near the surface up into the upper atmosphere, and, chemically, what goes on, and what impact that has," Maring says.
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