Smoke from wildfires in California and Colorado can make it hotter in Budapest. Isoprene, a naturally occurring hydrocarbon, rising in a summer mist from the forests of the Southeastern U.S., can damage the ozone layer that protects earth from harmful ultra violet radiation.
NASA’s Earth Science Division will employ three different aircraft and a fleet of satellites over the Southeastern U.S. this summer to collect data for a project called SEAC4RS, Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys. Quite a mouthful, meaning the researchers will examine the process of how localized pollutants change the composition of thunderstorms and invade the upper atmosphere, and how that impacts the global climate cycle.
In a prior study conducted by scientists at NASA’s Pacific Northwest Laboratory in June, 2012, it was found that locally-occurring contaminants such as car exhaust, factory smoke, and methane from cow manure rise with heat updrafts into the clouds of summer thunderstorms. Sucked up in the form of tiny aerosol particles, local pollutants mix with the water in the cloud when it condenses to form a thunderhead. The pollution then acts to divide the water droplets inside the storm cloud, making them too small to create rain. Polluted storm clouds, instead of bringing cool rain, become heat traps, gradually reflecting stored heat back to earth.
In the new SEAC4RS study, earth’s atmosphere will be probed from top to bottom with aircraft, satellite, and ground-based sensors at the critical time of year when regional air pollution and natural emissions pump gases and particles high into the atmosphere, with potentially global consequences for Earth’s climate.
Brian Toon of the University of Colorado, the study’s lead scientist, states, “In summertime across the United States, emissions from seasonal fires, metropolitan areas, and vegetation are moved upward by thunderstorms and the North American Monsoon. When these chemicals get into the stratosphere, they can affect the whole Earth. They may also influence thunderstorm behavior. We hope to better understand how all these things interact.”
Data will be collected from specialized instruments on (1) a fleet of formation-flying satellites known as NASA’s A-Train, (2) an ER-2 high-altitude aircraft that flies to the edge of space, (3) a DC-8 flying at lower levels, and (4) a specialty aircraft that measures cloud properties. A network of ground-based sensors will also be used.
By analyzing the collected data, the scientists expect to achieve a more precise understanding of how manmade and natural pollutants affect global climate: What happens when polluted clouds travel with a weather system? Which pollution particles are absorbed by clouds, and which go directly into the stratosphere, and in what amounts? What happens when the jet stream carries stratospheric pollution around the world? Knowing more about this process should help us find more and better ways to reduce emissions and slow the pace of global warming.