Comparison of a Modeled Spectra from the Hyperspectral Radiative Transfer Model (HRTM) with Spectra Measured by the Cross-Track Infrared Sounder (CrIS)

Clouds are an important component of the Earth’s energy budget. Clouds and aerosols, their distribution in the atmosphere, and their radiative properties, are key uncertainties in our understanding of climate change and our future in a warming environment. The Hyperspectral Radiative Transfer Model (HRTM) was developed as a fast and accurate simulator of scattering and absorbing atmospheres (see Wang et al, 2015: J. Atmo. Sci.). The current iteration of the model has the ability to input user defined profiles and to simulate scenes with water clouds, ice clouds, and aerosols in multiple user-defined layers within an atmospheric column. The current spectral resolution of HRTM is 0.1 cm^-1 with a spectral coverage of 700 cm^-1 to 1300 cm^-1. In preparation for future extensions of HRTM and to assess its abilities, we are conducting a radiative closure study of modeled spectra (in cloudy and clear skies) with measured spectra from the Cross-track Infrared Sounder (CrIS). Input to HRTM includes atmospheric profiles extracted from the Modern-Era Retrospective Analysis for Research and Applications-2 (MERRA-2). Agreement will be assessed through calculation of the model-measurement residual in conjunction with model and measurement uncertainties. Preliminary results will be presented.