A Fast and Efficient Method for Deriving 20 years of Climate Data Records from Multiple Satellite IR Sounders

Hyperspectral observations from satellite-based sensors provide high information content for the Earth’s atmospheric and surface properties. Deriving Climate Data Records (CDRs) from multiple IR sounders such AIRS on Aqua, CrIS on S-NPP, NOAA20 and JPSS-2, IASI on Metop A, B, and C from current operational products faces several challenges. First it is a time-consuming process to generate level-2 data products since modern hyperspectral satellite sensors have millions of observations each day with thousands of spectral channels for each observation. Additionally, differences in radiative transfer models and retrieval algorithms used to process level 2 data can lead to errors in the climate products when fusing data from different satellite sensors. We developed a Climate Fingerprinting Sounder Product (ClimFiSP) algorithm, which uses a single set of radiative kernels a robust spectral fingerprinting method to performs retrievals using spatiotemporally averaged L1 hyperspectral radiances directly. The ClimFiSP algorithm provides accurate data fusion CDR products from multiple satellite sensors. We have applied this method to both AIRS and CrIS (on SNPP and on NOAA 20) data and generated two decades climate data records at 0.5 by 0.5 degree grid on global scale. We plan to add IASI to the CDR data set in the future. The ClimFiSP CDR products will be released for public access in the first quarter of 2025 at the NASA Goddard Earth Sciences (GES) Data and Information Services Center (DISC). These long-term CDRs include: 1) vertical profiles of atmospheric temperature, water vapor, ozone, and carbon monoxide; 2) height, temperature, particle size, and optical depths for ice and water clouds, and 3) surface skin temperature and surface emissivity spectra.
In this presentation, decadal climate trends derived from satellite observations and from the EMCWF reanalysis will be compared. Emphasis will be given for the comparison results in the Polar regions. Examples of polar vortex break up will be presented.