Comparisons of cloud microphysics schemes implemented in KIAPS-GM

The Korea Institute of Atmospheric Prediction System-Global Model (KIAPS-GM) is a global numerical weather prediction (NWP) system with the element-based dynamical core on cubed-sphere grids. Initial version of the basic physics package as a part of the KIAPS-GM has been developed, including the radiation, cloud macrophysics/microphysics, convection, planetary boundary layer, gravity wave drag, and land surface. For cloud microphysics parameterization, we have implemented three different schemes in the 3-dimensional framework of KIAPS-GM; Weather Research and Forecasting model (WRF) Single-Moment 6-class microphysics scheme (WSM6, Hong and Lim 2006), WRF Double-Moment 6-class microphysics scheme (WDM6, Lim and Hong 2010), and single-moment bulk microphysics scheme based on Wilson and Ballard (1990). Performances by three different cloud microphysics schemes have been evaluated, based on spatiotemporal distribution and intensity of cloud and precipitation fields as well as computational efficiency, with comparing the characteristics and systematic biases between single-moment and double-moment methods. One of key uncertainties in cloud microphysics parameterization is the representation of hydrometeor size distribution function, particularly for the ice phase. The sensitivity analysis is executed with size distribution parameters for hydrometeors (e.g., intercept parameter, maximum and minimum values for slope parameter) to figure out their impacts on cloud microphysics.