Both images in the slide show the global spreading of carbon dioxide on the Earth globe as it follows the large scale patterns of the atmospheric general circulations. The color codes in these two images are different in order to account for the carbon dioxide increase from 2003 to 2007. The 2003 carbon dioxide image is the first global image to be derived from space observations. If the color bar for 2003 were to be used for 2007, the resulting 2007 map would be saturated with reddish colors, and the fine structure of the distribution of carbon dioxide obscured.
The Atmospheric Infrared Sounder, AIRS, in conjunction with the Advanced Microwave Sounding Unit, AMSU, senses emitted infrared and microwave radiation from Earth to provide a three-dimensional look at Earth's weather and climate. Working in tandem, the two instruments make simultaneous observations all the way down to Earth's surface, even in the presence of heavy clouds. With more than 2,000 channels sensing different regions of the atmosphere, the system creates a global, three-dimensional map of atmospheric temperature and humidity, cloud amounts and heights, greenhouse gas concentrations, and many other atmospheric phenomena. Launched into Earth orbit in 2002, the AIRS and AMSU instruments fly onboard NASA's Aqua spacecraft and are managed by NASA's Jet Propulsion Laboratory in Pasadena, Calif., under contract to NASA. JPL is a division of the California Institute of Technology in Pasadena.
More information about AIRS can be found at http://airs.jpl.nasa.gov.