Application Study of Radar Data in Lightning Warning
Cheng Bin · Journal of Chengdu University of Information Technology · 2011
The data obtained by Doppler radar,radiosonde and lightning location system from 41 convective cells,which occurred in the periods of July-August 2009 and June 2010,within 200km of the Qihe radar station were analyzed to study the lightning warning indicator.The characteristics of radar parameters ahead of lightning occurrence were studied by statistical method.The best predictor of the cloud-to-ground(CG) lightning was found to be a-40dBz reflectivity level detected at an altitude with an environmental temperature of-10℃,with an average leading time of 21 min.The percent of doom(POD),false alarm rate(FAR) and critical success index(CSI) are 96%,14% and 83%,respectively.Echo tops reaching or exceeding 10 km and vertically integrated liquid water content(VIL) exceeding 8.5kg·m-2 were necessary conditions prior to or at the time of the first CG lightning occurrence.When the three parameters(radar reflectivity,echo top height and VIL) were analyzed synthetically,it is found that the best predictor of the onset of CG lightning was a-25dBz reflectivity at an altitude with an environmental temperature of-20℃,which could effectively reduce the FAR and improve the CSI.