Known predominantly for its exploration of space, NASA also leads research efforts to improve our understanding of Earth’s atmosphere.
NASA may not initially leap to mind as an agency with an environmental mission, but since 1975, they have been charged with monitoring and conducting research on Earth’s upper atmosphere to maintain its chemical and physical integrity. Their research has substantially shaped our understanding of stratospheric ozone and the factors influencing our global climate.
Although land-based measurements of overhead ozone were invaluable to identify the depth of the seasonal ozone hole formation over Antarctica in 1985, data from NASA satellites which overfly the entire globe are the only way to survey the geographic size of the ozone hole on a daily basis. Instruments on NASA’s Aura satellite continue to collect data to observe the annual variation in global ozone levels and to monitor the results of international efforts to eliminate chlorofluorocarbons and return ozone concentrations to their original levels. More than thirty years of data may be viewed at http://ozonewatch.gsfc.nasa.gov/index.html.
In response to a shrinking budget for planetary exploration in the 1970’s, NASA shifted its focus to explore our own planet and issues of global change, including changing land use, ocean productivity and pollution. Currently, data from NASA’s Terra and Aqua satellites are providing the first comprehensive measurements of global aerosol levels. These aerosols, which may be produced by natural sources such as dust storms and volcanoes or from human activity such as burning fossil fuels, are a contributing factor to climate change, but without these new satellite data, it has been difficulty to evaluate the specific impact of aerosols reliably. The NASA satellites also collect data to monitor shrinking Arctic and land ice levels as well as rising sea levels, carbon dioxide concentrations, and global temperatures. The latest annual data are available at http://climate.nasa.gov/
NASA’s exploration of the chemistry of planet Earth may be as significant and important as their exploration of our solar system and beyond.