Development of Double Moment Scheme in Very High Resolution WRF Model and Evaluate the Existing Microphysics Process and New Scheme for High-Impact Weather System

This research examines the performance of the WRF Single-Moment (WSM) cloud microphysics for high-impact weathers in Korea on an idealized tested and real case runs. In addition, further special ingredient of the microphysics, that is, WRF-Double-Moment (WDM) bulk microphysics will be developed and tested its properties. Hong et al.(2004) has suggested ice microphysical processes, in order to overcome the deficiencies in widely used bulk parameterization schemes of cloud and precipitation in mesoscale models and Global Climate Models (GCMs). The concept of HDC was implemented into the WRF model as WSMMPs (WRF-single-moment-microphysics scheme). Now, we need more detailed cloud and precipitation process like Double-Moment microphysics scheme, as the grid size become smaller.

In this study, we conduct the further examination of WSMMPs performance and comparing with other cloud schemes in the WRF model for two dimensional idealized hill cases. And the real cases of heavy rainfall events over Korea on 14-15 July 2001 and 5-7 August 2002 are selected. The WRF model is set up with three nesting domains for each case. In ideal results, WSMMPs show stabilities in very high resolution up to 0.5km while the PLIN and Kessler schemes show unstable feature. And the performance of the WSM6 scheme has examined in detail against the widely used Purdue Lin scheme (PLIN) in real case simulations. In comparison of the graupel schemes (WSM6 vs. PLIN), both produce similar pattern in terms of distribution of precipitation and banded shape, but rainfall amount is reduced when WSM6 was used. And the location of major precipitation band from the PLIN experiment is shifted northward as the resolution becomes high. The performance of new WDMMPs and further analyses for the reasoning will be shown in the workshop.