Performance Evaluation of Radiation Parameterization in KIAPS-GM

Radiation plays an important role in the atmospheric physical processes where horizontal and vertical thermal state are determined through the absorption, reflection, and emission of solar and terrestrial radiation. Also, radiation, clouds, aerosols, and surface processes interact with each other in a very complicated way and it makes difficult to assess all the effect quantitatively. Thus, radiation is also very important process in numerical weather prediction model or climate model because fluxes and temperature tendencies are calculated through the radiative process and they affect other processes in the model. Simulating these processes in the numerical weather prediction model or climate model is very challenging and numerous efforts have been made. Currently, Korea Institute of Atmospheric Prediction Systems (KIAPS) is developing a state-of-the-art global numerical weather prediction model (KIAPS-GM) and Rapid Radiative Transfer Model for General Circulation Models (RRTMG) based radiation parameterization is developed for the KIAPS-GM physics package. In this study, radiative fluxes and temperature tendencies from KIAPS-GM are compared and evaluated using observations and other reanalysis data to check model performances. Also, various factors which interact with radiation such as clouds, aerosols, and surface processes are analyzed to assess the effect on radiation qualitatively and quantitatively. These analyses will provide the basis for the development of faster, more realistic, and more accurate radiation parameterization for KIAPS-GM.