The Probability Density Function Related to Shallow Cumulus Entrainment Rate and Its Influencing Factors in a Large-Eddy Simulation

作     者：Lei ZHU Chunsong LU Xiaoqi XU Xin HE Junjun LI Shi LUO Yuan WANG Fan WANG Lei ZHU;Chunsong LU;Xiaoqi XU;Xin HE;Junjun LI;Shi LUO;Yuan WANG;Fan WANG

作者机构：Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)and Key Laboratory for Aerosol-Cloud-Precipitation of China Meteorological AdministrationNanjing University of Information Science and TechnologyNanjing 210044China Nanjing Joint Institute for Atmospheric SciencesNanjing 210019China College of Aviation MeteorologyCivil Aviation Flight University of ChinaGuanghan 618307China Collaborative Innovation Center for Western Ecological SafetyLanzhou UniversityLanzhou 730000China Department of GeographyHong Kong Baptist UniversityHong Kong SAR 999077China 

出 版 物：《Advances in Atmospheric Sciences》 (大气科学进展（英文版）)

年 卷 期：2024年第41卷第1期

页      面：173-187页

核心收录：

学科分类：07[理学] 0706[理学-大气科学] 0701[理学-数学] 070101[理学-基础数学] 

基　　金：supported by the National Natural Science Foundation of China(Grant Nos.42175099,42027804,42075073) the Innovative Project of Postgraduates in Jiangsu Province in 2023(Grant No.KYCX23_1319) supported by the National Natural Science Foundation of China(Grant No.42205080) the Natural Science Foundation of Sichuan(Grant No.2023YFS0442) the Research Fund of Civil Aviation Flight University of China(Grant No.J2022-037) supported by the National Key Scientific and Technological Infrastructure project“Earth System Science Numerical Simulator Facility”(Earth Lab) 

主　　题：large-eddy simulation cumulus clouds entrainment rate probability density functions spatial and temporal distribution 

摘      要：The process of entrainment-mixing between cumulus clouds and the ambient air is important for the development of cumulus *** obtaining the entrainment rate(λ)is particularly important for its parameterization within the overall cumulus parameterization *** this study,an improved bulk-plume method is proposed by solving the equations of two conserved variables simultaneously to calculateλof cumulus clouds in a large-eddy *** results demonstrate that the improved bulk-plume method is more reliable than the traditional bulk-plume method,becauseλ,as calculated from the improved method,falls within the range ofλvalues obtained from the traditional method using different conserved *** probability density functions ofλfor all data,different times,and different heights can be well-fitted by a log-normal distribution,which supports the assumed stochastic entrainment process in previous *** analysis demonstrate that the relationship betweenλand the vertical velocity is better than other thermodynamic/dynamical properties;thus,the vertical velocity is recommended as the primary influencing factor for the parameterization ofλin the *** results of this study enhance the theoretical understanding ofλand its influencing factors and shed new light on the development ofλparameterization.