Study On The Application Of Lightning Data In GRAPES Cloud Analysis System

The GRAPES Cloud Analysis System(GRAPES_gcas)is a system that combines Doppler weather radar data,satellite data and ground cloud observation data to adjust cloud information generated by the model.The research and application of GRAPES can make the initial field of numerical model contain cloud information,which is one of the great important improvements of the technique of modern numerical forecasting.Currently,lightning location data has not been used in the GRAPES_gcas.The research on the application of lightning location data in numerical forecasting in China is not enough now.Firstly,the existing cloud analysis system is used to simulate the sevier weather process and analyze the lightning location data at the same time.The method of applying lightning location data to the cloud analysis system has been raised in this paper.Finally,this paper analyzes the application of cloud analysis system through comparative numerical experiments including various observation data,and focuses on the application of ADTD lightning location data research.The conclusions are as follows:(1)The lightning rate is converted into three-dimensional reflectivity based on the empirical relationship.Along with the Doppler radar reflectivity 3D network puzzle data,it is used to adjust and analyze the cloud micro-physical variables such as cloud water and cloud ice in the initial field by the cloud analysis system in GRAPES.(2)In response to two different strong convective activities in the area of Shanxi and Shandong in June 2016 and south of China,several sets of different numerical tests based on different observed data are designed.Firstly,the direct influence of adding lightning location information to radar reflectivity during cloud analysis is compared and analyzed.Secondly,the changes of cloud micro-physical variables(cloud water,cloud ice and snow)are compared and analyzed at the initial time of the model.Finally,the forecast effect of model precipitation is compared..And on this basis,further batch tests were conducted.The results show that:(a)After added the radar reflectivity data,the initial water species of the model are calculated more accurately in the initial field of the model by the cloud analysis system;(b)The agent radar reflectivity converted from lightning location data has a certain complementary effect to the original radar reflectivity which makes the initial field of the model more similar to the real situation.(c)From the perspective of model precipitation,GRAPES cloud analysis can significantly improve the simulation effect of precipitation within 6 hours with radar data.The addition of lightning location data can also improve the rainfall simulation of magnitude above mid-rain.(d)When it comes to a one-week batch experiment,the result shows that the lightning located data can play a positive role in the prediction of precipitation when convective weather features are obvious and the lightning rate is high.That is to say,the addition of lightning location data has a positive effect on the prediction results of the model.(3)As the result,the research in this paper shows that the application of lightning location information is a further improvement and Supplement to the GRAPES cloud analysis system with Chinese independent intellectual property rights.It provides a valuable reference and basis for the further application of lightning location information in China's numerical forecasting.It should be of significance in improving the initial field and the accuracy of prediction in grapes model,especially in severe convective weather.