Atmospheric profiles over land and ocean from AMSU

An optimal estimation, simultaneous retrieval of water vapor profile, temperature profile, cloud liquid water and surface emissivity from Advanced Microwave Sounding Unit observations is presented. The major innovation in the method is the ability to perform retrievals over land surfaces. A global matchup radiosonde and AMSU dataset was created for September 2003 and used to evaluate the retrieval performance. Comparisons of retrieved total precipitable water to Global Positioning System (GPS) results are also shown.

The sensitivity of this retrieval to formulations in the land surface emissivity first guess and covariance constraints is investigated. A new formulation for cloud liquid water over both land and ocean is developed. By performing a simultaneous retrieval of the atmosphere and surface, the profiling and emissivity results synergistically reinforce each other.

The AMSU-A and AMSU-B instruments from onboard NOAA-16 and –17 are the primary data inputs currently. DMSP SSMIS data will be tested with the retrieval system once available. In addition to the comparison with rawinsondes and GPS sites, sample maps of retrieved moisture and temperature fields will be presented.