Abstract
A continuous hyperspectral infrared radiance record of the Earth's emission started with AIRS in 2002 in the 1:30 orbit, followed by IASI in 2007 in the 9:30 orbit. The follow-on to AIRS, CrIS, began operation in early 2012, also in the 1:30 orbit. The AIRS record will soon span 13 years, long enough to start providing climate-level information. Both Cris and IASI are operational programs, slated to continue for 15+ years or more, so the importance of these sensors for climate studies will continue to grow. We discuss here the utility, and construction, of an homogenous radiance record from these sensors that could provide a well understood climate record with known error characteristics. Issues reviewed will include spectral response normalization, inter-calibration, and data sub-setting. Approaches to independently access individual instrument stability at the climate level will be introduced using optimal estimation retrievals of geophysical variability from radiance time derivatives taken over decadal time periods.
An Infrared Radiance Climate Record Combining EOS-AIRS, S-NPP/JPSS CrIS, and METOP IASI
A continuous hyperspectral infrared radiance record of the Earth's emission started with AIRS in 2002 in the 1:30 orbit, followed by IASI in 2007 in the 9:30 orbit. The follow-on to AIRS, CrIS, began operation in early 2012, also in the 1:30 orbit. The AIRS record will soon span 13 years, long enough to start providing climate-level information. Both Cris and IASI are operational programs, slated to continue for 15+ years or more, so the importance of these sensors for climate studies will continue to grow. We discuss here the utility, and construction, of an homogenous radiance record from these sensors that could provide a well understood climate record with known error characteristics. Issues reviewed will include spectral response normalization, inter-calibration, and data sub-setting. Approaches to independently access individual instrument stability at the climate level will be introduced using optimal estimation retrievals of geophysical variability from radiance time derivatives taken over decadal time periods.