Estimation of outgoing longwave radiation from Atmospheric Infrared Sounder radiance measurements

Abstract

This study demonstrates the ability to use Atmospheric Infrared Sounder (AIRS) hyperspectral radiance measurements and collocated Clouds and the Earth's Radiant Energy System outgoing longwave fluxes to estimate top‐of‐atmosphere outgoing longwave radiation (OLR) from AIRS radiance measurements. The first 35 principal component scores of AIRS radiances from its 1707 pristine channels are used as predictors, and the regression coefficients are generated in eight regimes of AIRS view angle to account for angular dependence of the AIRS radiance observations. Tests on an independence test ensemble show that the accuracy of the AIRS OLR is near zero and the precision is less than 3 Wm−2 for all scenes and 2 Wm−2 for uniform scenes. The AIRS OLR precision for uniform scenes is much higher than the High‐Resolution Infrared Sounder OLR of 5 Wm−2 for similar comparisons with the Earth Radiation Budget Experiment OLR. The same technique of empirical regression OLR can be applied to other hyperspectral sounders such as the Cross‐track Infrared Sounder that will be on board the National Polar‐Orbiting Operational Environmental Satellite System and the Infrared Atmospheric Sounding Interferometer on the European Meteorological Polar‐orbiting satellites.

Validation of Near-Real-Time NOAA-20 CrIS Outgoing Longwave Radiation with Multi-Satellite Datasets on Broad Timescales

“…To evaluate CrIS OLR products, the package utilizes an approach that uses the Aqua CERES OLR as the absolute reference and the Aqua AIRS OLR as the third transfer. Previous analyses of Aqua CERES and AIRS OLR have shown that they are stable over the time period of this study [13,14], and are therefore suitable for our validation analysis. Included in our validation analysis are the two CrIS OLR products evaluated with the NUCAPS: the SNPP CrIS OLR and the NOAA-20 CrIS OLR.…”

“…Satellite OLR products are generated mainly from broadband [6][7][8][9], multispectral [10,11], and hyperspectral datasets [12][13][14]. The Clouds and Earth's Radiant Energy System (CERES) instruments are examples of broadband sensors that directly measure reflected solar radiation and Earth-emitted radiation from TOA to the surface, thus providing records of spatial and temporal variations of ERB components.…”

“…In our validation analysis, the datasets were chosen to be Aqua CERES OLR, SNPP CrIS OLR, and NOAA-20 CrIS OLR (to be validated). Similar to previous OLR product validation analyses [13,14], the Aqua CERES OLR products were treated as the truth [26]. The NOAA-20 OLR products will be compared with the validated SNPP CrIS OLR products to ensure the CrIS product consistency.…”

The Atmospheric Infrared Sounder (AIRS) on the NASA Aqua Spacecraft: a general remote sensing tool for understanding atmospheric structure, dynamics, and composition

“…The results show a mean difference of 0.3 W/m 2 from CERES with a standard deviation of 2.7 W/m 2 . These results indicate that AIRS can be used to monitor CERES and serve as a backup in the event of failure 16 , but more importantly, the AIRS provides attribution of the observed OLR to changes in geophysical variables such as temperature profile, water vapor profile and dust aerosols.…”

Satellite based remote sensing of weather and climate: recent achievements and future perspectives

“…As a result, the Clouds and Earth Radiant Energy System (CERES) sensor was designed to provide radiation fluxes at the surface and at levels throughout the atmosphere and to investigate the cloud‐radiation feedback on the Earth's climate system (Wielicki et al , 1996; Loeb et al , 2001; Geier et al , 2003). Huang et al (2008) and Sun et al (2010) used collocated AIRS hyperspectral radiance measurements and CERES outgoing long wave fluxes to estimate TOA OLR from AIRS radiance measurements.…”