Large Eddy Simulation of Microphysics and Influencing Factors in Shallow Convective Clouds
Zhuangzhuang Zhou,
Chongzhi Yin,
Chunsong Lu,
Xingcan Jia,
Fang Ye,
Yujun Qiu,
Muning Cheng
Affiliations
Zhuangzhuang Zhou
Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD) and Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing 210044, China
Chongzhi Yin
Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD) and Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing 210044, China
Chunsong Lu
Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD) and Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing 210044, China
Xingcan Jia
Institute of Urban Meteorology, Chinese Meteorological Administration, Beijing 100089, China
Fang Ye
College of Meteorology and Oceanography, National University of Defense Technology, Changsha 410000, China
Yujun Qiu
Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters (CIC-FEMD) and Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological Administration, Nanjing University of Information Science and Technology, Nanjing 210044, China
Muning Cheng
Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment Technology, School of Environmental Sciences and Engineering, Nanjing University of Information Science and Technology, Nanjing 210044, China
A flight of shallow convective clouds during the SCMS95 (Small Cumulus Microphysics Study 1995) observation project is simulated by the large eddy simulation (LES) version of the Weather Research and Forecasting Model (WRF-LES) with spectral bin microphysics (SBM). This study focuses on relative dispersion of cloud droplet size distributions, since its influencing factors are still unclear. After validation of the simulation by aircraft observations, the factors affecting relative dispersion are analyzed. It is found that the relationships between relative dispersion and vertical velocity, and between relative dispersion and adiabatic fraction are both negative. Furthermore, the negative relationships are relatively weak near the cloud base, strengthen with the increasing height first and then weaken again, which is related to the interplays among activation, condensation and evaporation for different vertical velocity and entrainment conditions. The results will be helpful to improve parameterizations related to relative dispersion (e.g., autoconversion and effective radius) in large-scale models.