CALIPSO is a joint satellite mission between NASA and the French Space Agency, CNES, that combines an active lidar instrument with passive infrared and visible imagers to probe the vertical structure and properties of optically thin clouds and aerosols. The CALIPSO lidar (named CALIOP) is polarization-sensitive and operates at dual wavelengths of 532 and 1064 nm. It has a sampling rate of 20.16 Hz to produce about 1.74 million profiles each day. The profile vertical resolution is 30 and 60 m for the 532 and 1064 nm channels, respectively. CALIPSO was launched on April 28, 2006 with the cloud profiling radar system on the CloudSat satellite, and orbits in formation with three other satellites in the A-Train constellation. Added information on CALIPSO and its data products is available at www-calipso.larc.nasa.gov.

Observations from CALIOP reveal rich and, at times, complex distributions of clouds and aerosols over the globe. CALIPSO's new profile information on depolarization and color ratio provides further insight into the composition of these distributions by identifying the frequency of occurrence of ice, water and mixed phase clouds as well as aerosol types (dust, smoke, sea salt, and urban pollution). Significant highlights of the mission include the first comprehensive view of aerosol and clouds over the arctic and Antarctica during the polar night, a detailed examination of the occurrence of visible and subvisible cirrus in the tropics and subtropics, a characterization of the altitude, depth and location of layers of enhanced aerosol loading and a 3D view of polar stratospheric clouds over Antarctica. This presentation will provide a mission overview and will highlight some of these results. It will feature seasonally averaged cloud and aerosol observations obtain by and with comparisons with other satellite sensors (e.g., CloudSat and MODIS).