Abstract:
This thesis analyzes the thunderstorm occurred on Aug 31,2011 based on weather radar data of Shangri-La airport together with routine aerological observation data,satellite cloud picture data and lightning positioning system data ,and the result shows,the outer-ring northeast wind of the high pressure in the east and ?the outer-ring northeast wind of the tropical depression in the southeast coast and the southerly wind of tropical depression in the bay of Bengal accumulate vapor and instability energy for the thunderstorm this time,and consequently lead to the thunderstorm triggered by active atmospheric convection in Shangri-La which locates in southeast Tibetan Plateau;and the analysis of radar echoes shows that the centric intensity is up to 55dBz when the thunderstorm occurs;thunderstorm belt is around the area where the negative micro second wave flashover is of the highest value.The thunderstorm this time also tested the lightening identifying indicator based on radar data,which is 40dBz radar echo get to -10℃ stratification height.Compared with lightning positioning data,this lightening identifying indicator is proved to be capable of detecting the lightening area correctly.
In radar echo chart,small clouds with strong echoes embedded in extensive stratiform clouds combine with each other to strengthen and form a more typical monomer clouds,Doppler radial velocity variations can better reveal the characteristics of the occurrence and development trend of lightning.adverse wind region is the thunderstorm central area,which is the central area of heavy rain and of lightening area as well.Therefore,monitoring the adverse wind region can better the prompt detection of thunderstorm warning MCS clouds in satellite images merge into one another and form typical strong convective cloud,and larger the scale,lower the brightness temperature,and the cloud has been strengthened.These preliminary indicators should have some value on the thunderstorm weather analysis in southeastern Tibetan Plateau.