Numerical Simulation Analysis Of Thunderstorm Weather In Sichuan Basin Based On WRF Electrical Coupling Model

This paper simulates the strong thunderstorm weather process that occurred in Sichuan on August 18,2010,and obtained the corresponding dynamic and microphysical output fields.The electric discharge physical process is introduced in the WRF mode Morrison two-parameter microphysical scheme to better utilize the WRF mesoscale model for numerical prediction of lightning activity.The results show:(1)The lightning distribution of the mode output is close to the observed lightning distribution.The location of the strong precipitation center is in line with the actual situation.The WRF can reflect the strong convective weather very well.The unstable parameter characteristics CAPE value and CIN value can indicate that the ground flash frequency changes with time,and can spatially indicate the center of the large flash density.(2)The echo large value area with combined reflectivity greater than 45 dBZ can indicate the ground flash area,and the vertical updraft strong energy indicates the increase of ground flashing activity.The thunderstorm cold outflow is conducive to convection strengthening,forming a local cyclonic vortex.Promote the formation of strong convective weather,and the formation of cold pools contributes to the advance warning of strong thunderstorms.The relative helicity of the storm and the helicity of the ascending airflow can indicate the center of the strong convective weather.The potential vortex is enhanced and the unstable energy is gradually enhanced,which is conducive to the occurrence torm can indicate that the flash frequency changes with time,and can spatially indicate the center of the large flash density.(3)The maximum mixing ratio of strontium particles in the charge separation region is consistent with the trend of the frequency of the ground flash with time.In the spatial distribution,the maximum position of the strontium,ice crystal and snow particles correspond to the center position of the large value of the ground flash density,and both can indicate the area where the ground flash occurs.The collision of bismuth particles with ice crystal grains and snow particles mainly occurs in the6-8km region and separates to generate negative charges.The ruthenium particlescarry negative charge density after collision and separation,and the ice crystal particles collide and separate positive charge,and the graup particle number concentration vertical height position It plays a key role in collision separation of microphysical particles.The charge structure is a positive charge region carried by the ice crystal grains and snow particles in the upper part,and a dipole structure in the negative charge region carried by the ruthenium particles in the lower part.The positive charge region is mainly located at 6-11 km,and the lower negative charge region is located at 3-6 km.The vertical distribution of the particles of the aqueous particles has a key influence on the formation of the charge structure in the thunderstorm cloud.The peak evolution of the particle content has a certain indication effect on the ground flash.(4)The simulation results show that the mode microphysical and power output fields can indicate the time and location of the ground flash activity,and have certain early warning and forecasting effects.