An Infrared Radiance Climate Record Combining AIRS and CrIS

Abstract:

A continuous hyperspectral infrared radiance record of the Earth's
emission started with AIRS in 2002 in the 1:30 orbit, supplemented
since 2012 with the SNPP-CrIS sensor, which is the first of at least
three planned sensors. This series of sensors is now well into their
second decade of operation, and will soon provide a wide range of
climate trends. Here we describe an approach for deriving climate
level trends in a homogenous radiance record that starts with AIRS
and is continued with the CrIS series of sensors. This approach
converts the L1b AIRS radiance record to the CrIS sensor grid and
spectral resolution, providing a long-term radiance record with
accuracies limited by the stability of the individual instrumnents,
our ability to convert AIRS radiances to the CrIS spectral grid, and
the corrections for radiometric offsets between these sensors. We
will examine decadal radiance trends, which are converted to
geophysical trends using a simple, all-sky, optimal estimation
retrieval with traceable error characteristics. These results will be
compared to zonally averaged temperature and water vapor profile
otrends derived from the ERA Interim reanalysis, the MERRA reanalysis,
and the NASA AIRS Level 3 products.