AN SENSITIVITY SIMULATION ABOUT CLOUD MICROPHYSICAL PROCESSES OF TYPHOON CHANCHU

With the Reisner-2 bulk microphysical parameterization of the fifth-generation Pennsylvania State University-U.S.National Center for Atmospheric Research(PSU-NCAR)Mesoscale Model(MMS),this paper investigates the microphysical sensitivities of Typhoon Chanchu.Four different microphysical sensitivity experiments were designed with an objective to evaluate their respective impacts in modulating intensity forecasts and microphysics budgets of the typhoon.The set of sensitivity experiments were conducted that comprised(a)a control experiment(CTL),(b)NEVPRW from which evaporation of rain water was suppressed,(c)NGP from which graupel was taken,and(d)NMLT from which melting of snow and graupel was removed.We studied the impacts of different cloud microphysical processes on the track,intensity and precipitation of the typhoon,as well as the kinematics,thermodynamics and vertical structural characteristics of hydrometeors in the inner core of the typhoon.Additionally,the budgets of the cloud microphysical processes in the fine domain were calculated to quantify the importance of each microphysical process for every sensitivity experiment.The primary results are as follows:(1)It is found that varying cloud microphysics parameters produce little sensitivity in typhoon track experiments.(2)The experiment of NGP produces the weakest storm,while the experiment of NMLT produces the strongest storm,and the experiment of NEVPRW also produces stronger storms than CTL.(3)Varying parameters of cloud microphysics have obvious impacts on the precipitation,kinematics,and thermodynamics of the typhoon and the vertical structural characteristics of hydrometeors in the typhoon's inner core.(4)Most budgets of cloud microphysics in NMLT are larger than in CTL,while they are 20%-60% smaller in NEVPRW than in CTL.