Lightning Monitoring With Doppler Weather Radar And Lightning Location Systems SAFIR 3000 And ADTD

This research is based on the data of the Doppler weather radar and thelightning location systems (SAFIR3000, ADTD) in Wuhan neighborhood. Afteranalyzing the lightning data widely, we can draw some conclusions as the follow:(1) The Z (the ratio of IC number and CG number) average is higher in thesouthern Wuhan than in the northern Wuhan, diurnal variation reaches maximum at05-06 A.M. and minimum at 19-20 P.M. The variation of Z has a close relation withthe influence of underlying surface on thunderstorms intensity. The typical electricalstructure of thunderclouds in Wuhan is a dipole type: main positive at the top, mainnegative in the middle, and lower positive at the bottom.(2) The yearly variation of the monthly flash number is a type with a primarypeak and a secondray peak, the first peak (secondray) occurs in April and the second(primary) in August. Diurnal variation of lightning number presents a pair of peakstoo, which shows more oceanic characteristics in the southern region than in thenorthern region. More Lightning activities are there in the south than in the north, inthe east than in the west. Flash density value distribution is much associated withwaters and mountains, and the main high flash density area falls in the southern area.The thermal island effect of Wuhan city is also important for informing the spatialdistribution of flash density value. The yearly and the monthly variation of ICnumber with altitude (6km above) are single peak type, with maximum at about 9kmand 10% or more few of IC total number beyond 15km because of the existence ofstratosphere.(3) The correlation between atmospheric instability parameters and lightningactivities is different in Wuhan area than in Beijing area, which indicates that theinfluence of atmospheric instability on lightning may vary from one region toanother.(4) The correlation between flash number and area of CAPPI radar echo'sintensity is much good, varying with altitude or intensity, which indirectly reflectsthe physical processes of electrical action in thunderclouds. The correlation betweencurrent CG number and area of recent CAPPI radar echo's intensity is obviouslyweaker than the correlation calculated by previous radar data of 7-19 minutes before,and the result calculated by previous radar data of 13 minutes before is the best. Inaddition, the area of CAPPI radar echo's intensity (45dBz) at -10℃layer of 7-19minutes before has a strong correlation with current CG number, which may resultfrom descending of main negative layer in altitude. Environmental winds can affect electric charge distribution in thunderclouds, leading to the position changing of ICor of CG. It makes forecasting of lightning more difficult, and at the end stage ofthunderstorms development, the characteristicses of CG-scatter, and few count-makethings worse. Analyses also show some probability for forecasting of lightning usingradar echo tops data.