Improved Monitoring of Inter-annual Temperature Variability Using AIRS/AMSU Observations

AIRS/AMSU was launched on EOS Aqua in May 2002 and started producing useful data in September 2002. EOS is primarily a mission for studying inter-annual variability of the Earth's surface and atmospheric geophysical parameters for the purpose of improving understanding of climate processes. Surface skin temperature and atmospheric temperature profiles are among many geophysical parameters derived from analysis of AIRS/AMSU observations. The Goddard DAAC had previously analyzed AIRS/AMSU observations starting from September 2002 using the AIRS Science Team Version 4 retrieval algorithm. The AIRS Science Team Version 5 retrieval algorithm became operational at the Goddard DAAC in July 2007 for use in processing AIRS/AMSU data subsequent to that time, and also for reprocessing all the old AIRS/AMSU data. Version 5 contains substantial improvements in capabilities compared to Version 4, especially with regard to improved spatial coverage of retrievals deemed acceptable for generation of climate data sets. These differences in methodology will be briefly described, and results will be shown demonstrating that inter-annual differences of surface and atmospheric temperatures obtained using the Version 5 algorithm are superior to those found in the previous AIRS data record obtained with the Version 4 algorithm.