Multi-source Data Analysis Of Danzhou Tornado And Kaiyuan Tornado

Tornadoes occur in severe convective weather with small scale and rapid development.Doppler weather radar has high temporal and spatial resolution,which is conducive to monitoring and early warning the mesoscale weather system and evolution of tornado.In order to study the structure and evolution of the tornado,this paper analyses the evolution process of tornado in Danzhou,Hainan and Kaiyuan,Liaoning by using dual polarization Doppler weather radar data,Doppler weather radar data and MICAPS data.The differences of the weather background and thermal factors between Danzhou tornado in Hainan and Kaiyuan tornado in Liaoning are compared and analyzed.The tornado cyclones are located in the easterly and westerly systems,and occur in the early morning and afternoon respectively.The main factor for the formation of Danzhou tornado is the dynamic uplift.The thermal factor of Kaiyuan tornado is the main factor.The sea surface nearby brings sufficient water vapor to the low level,thus forming the unstable characteristics of strong convective weather,Compared with Danzhou tornado,Kaiyuan tornado’s "bee waist" image features and the instability of the surrounding area are more obvious and lasting.This provides more basis for the potential prediction of strong convective weather such as tornado..When diagnosing the atmospheric physical quantity of severe convective weather,this paper not only uses the T-log P diagram to analyze the convection index,but also uses the wind vector-potential temperature(V-3?)diagram to analyze the characteristics of the atmospheric energy structure of severe convective weather such as tornadoes.The two tornadoes are characterized by the super low temperature layer at the top of troposphere and the strong cooling layer in the middle layer,.Compared with the base data of single polarization Doppler radar,the dual polarization parameters of dual polarization radar can obtain more information.The analysis of velocity echo before and after Tornado highlights the evolution of mesocyclone and tornado vortex characteristics(TVS)and characteristics.The velocity pair is clear,and the tornado develops from the air to the ground.It is found that the velocity pair of TVs is anticyclone when the tornado reaches the ground,which verifies the three-dimensional structure of the tornado vortex tube.Compared with the single polarization information of Kaiyuan tornado,the dual polarization parameters of Danzhou tornado can display the tornado fragment characteristics(TDS),and can better monitor the tornado position and intensity It provides key information for Doppler Weather Radar to monitor and early warn tornado evolution...