Although originally designed to measure atmospheric water vapor and temperature profiles for weather forecasting, data from the Atmospheric Infrared Sounder (AIRS) instrument on NASA's Aqua spacecraft are now also being used by scientists to observe atmospheric carbon dioxide. Scientists from NASA; the National Oceanic and Atmospheric Administration; the European Center for Medium-Range Weather Forecasts; the University of Maryland, Baltimore County; Princeton University, Princeton, New Jersey; and the California Institute of Technology (Caltech), Pasadena, Calif., are using several different methods to measure the concentration of carbon dioxide in the mid-troposphere (about eight kilometers, or five miles, above the surface).
This visualization shows Aqua/AIRS mid-tropospheric carbon dioxide from July 2003. Low concentrations, 360 ppm, are shown in blue and high concentrations, 385 ppm, are shown in red. Notice that despite carbon dioxide's high degree of mixing, the regional patterns of atmospheric sources and sinks are still apparent in mid-troposphere carbon dioxide concentrations. This pattern of high carbon dioxide in the Northern Hemisphere (North America, Atlantic Ocean, and Central Asia) is consistent with model predictions.