Comparison of two double-moment microphysics schemes in aspects of warm-rain droplet spectra and raindrop budget

Hengchi Lei,Jiaxu Guo,Jiefan Yang,Di Chen

doi:10.1080/16742834.2019.1664882

Abstract

ABSTRACTSimulation results of the WDM6 scheme and the Thompson scheme, both of which are commonly-used double-moment bulk microphysics schemes, are compared within the Weather Research and Forecast...

Highlights

Microphysics parameterization determines the evolution of hydrometeors, affects latent heat release, and interacts with dynamics
The objective of this paper is to explore the differences in droplet spectra and the microphysical causes of the differences between two commonly used double-moment bulk schemes in the Weather Research and Forecasting (WRF) model (Skamarock and Klemp 2008) through a budget analysis
The simulation basically agrees with observations in terms of rainfall location and accumulated precipitation when either of the two schemes is used, there are notable differences in the aspects of surface precipitation, warm-rain droplet size distributions (DSDs) and droplet number concentration, among others

Summary

Introduction

Microphysics parameterization determines the evolution of hydrometeors, affects latent heat release, and interacts with dynamics. Simulations of different microphysics schemes were compared with remote-sensing observations with respect to the aspects of reflectivity, differential reflectivity, and microwave brightness temperature, among others, to analyze the characteristics of droplet spectra without explaining the cause of droplet spectra differences (Gao et al 2011; Jankov et al 2011; Molthan and Colle 2012; Johnson et al 2016). Few of these studies concentrated on droplet number concentrations, spectra and identifying microphysical causes of differences between microphysics schemes. The objective of this paper is to explore the differences in droplet spectra and the microphysical causes of the differences between two commonly used double-moment bulk schemes in the WRF model (Skamarock and Klemp 2008) through a budget analysis

Model configuration

Precipitation

Hydrometeors

Budget analysis of raindrops

Summary