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In the Weather Research and Forecasting (WRF) Double-Moment 6-class (WDM6) cloud microphysics scheme, hydrometeors are characterized by fixed densities, mass?diameter relations, and fall velocity?diameter relations, which prevents the representation of intermediate solid-phase hydrometeors such as between snow and graupel (or graupel and hail). To improve the ice microphysical processes in WDM6, this study introduces a double-moment treatment for solid-phase hydrometeors and a prognostic graupel density formulation. The graupel density is prognosed based on the predicted graupel volume mixing ratio and can range from 100 to 900 kg m??. Furthermore, new fall velocity?diameter relations are derived to account for density variations, enabling the representation of density-dependent fall velocities. A generalized double-moment normalization method is also implemented in WDM6 to reduce variability in particle size distributions. The performance of the newly proposed WDM6 scheme is evaluated using observational data from the International Collaborative Experiment for Pyeongchang Olympics and Paralympics (ICE-POP 2018) field campaign over the Korean Peninsula and from the Boseong surface weather observation site. This presentation will introduce the improvements and validation results of the revised WDM6 scheme, as well as the observational data collected during the intensive field campaign that supported the development and evaluation of the cloud microphysics parameterization.
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