A Double‐Moment SBU‐YLIN Cloud Microphysics Scheme and Its Impact on a Squall Line Simulation

Abstract

A double‐moment version of the SBU‐YLIN cloud microphysical scheme in WRF is introduced. It predicts the mass and number mixing ratios of cloud droplet, rain, cloud ice, and precipitating ice. In addition, a number of physical processes, like rain evaporation, collection between rain and snow are also optimized in the new scheme. The scheme is evaluated and compared with the original one‐moment scheme for a squall line case. We found that the double‐moment approach gives a better representation of rain evaporation, which is critical for the development, morphology, and evolution of the simulated squall line, especially for the enhanced trailing stratiform cloud and leading convective line. The relationship between key microphysical processes and squall line dynamics is investigated to identify the driving mechanisms of the descending rear inflow, cold pool, and slantwise updraft. Furthermore, formation of the transition zone in the simulated squall line strongly depends on the flexible description of ice particle properties, such as size, degree of riming and fall speed.

Towards Ensemble-Based Kilometer-Scale Climate Simulations over the Third Pole Region

“…Gray cells indicate that the correspondent physics option has been changed compared to the WRF reference setup (Table 1. Name MYNN2.5 [101,116,117] MYJ [118,119] MYNN3 [101,116,117] BouLac [120] QNSE, [121] UW CAM [122] Shin-Hong [123] GMB [124] Noah LSM 1 [125] WDM7 [126] WDM6 [127] Morrison [128] Ylin [129] CAM [ 2 Multi-scale Kain-Fritsch deep convection scheme.…”

Combining Triple‐Moment Ice With Prognostic Liquid Fraction in the P3 Microphysics Scheme: Impacts on a Simulated Squall Line

“…Since the cold pool is mainly driven by melting and rain evaporation, the cold pool parameters are investigated to study the impacts of mixed‐phase particles on microphysical processes. The methods to compute the cold pool speed vary between studies (e.g., Bryan et al., 2006; Fan et al., 2017; Jouan & Milbrandt, 2019; Morrison et al., 2015; Zhao et al., 2021). Many previous studies, including with real cases, compute the cold pool properties over some region where the perturbation of potential temperature is less than −1 or −2 K or over a selected small region behind the gust front.…”

“…The new version is tested in the context of mesoscale model simulation, with a 1‐km horizontal grid spacing, of a mid‐latitude squall line and is compared to simulations with simpler configurations of P3, including with 2‐moment ice, with and without mixed‐phase particles, and 3‐moment ice without mixed‐phase particles. Numerical simulations of a squall line help to identify the impacts of microphysics on storm dynamics, development and persistence, while allowing to study the impacts of parameterization on both the convective and the stratiform parts of the precipitation simultaneously (e.g., Adams‐Selin et al., 2013a, 2013b; Bao et al., 2019; Cao et al., 2022; Han et al., 2019; Jensen et al., 2018; Li et al., 2021; Liu et al., 1997; Morrison et al., 2009, 2015; Wen et al., 2017; Wu et al., 2013; Zhao et al., 2021). This study examines how explicitly representing mixed‐phase particles impacts melting, sublimation, and evaporation, since these processes are critical for generating cold pools that drive the propagation of squall lines (e.g., Dawson et al., 2010; Houze, 2018; Tao et al., 1995).…”

Investigating the Effect of Aerosol Uncertainty on Convective Precipitation Forecasting in South China's Coastal Area

“…Yin et al. (2018) suggest that latent heating is an important factor in governing the intensity of convection, while rain evaporation is also suggested as a critical process due to its effect on regulating cold pool intensity (Qian et al., 2018; Zhao et al., 2021; Zhou et al., 2022). Zhao et al.…”