Echo Analysis Of Dual Polarization Radar For Artificial Precipitation Reduction In Nanjing Youth Olympic Games Opening And Closing Ceremonies

For the assessment effect of artificial reducing precipitation operation on major games venues, the operation effect within the August 16 and 28, 2014 Nanjing Youth Olympic Games opening and closing ceremony of are analyzed with the data of dual polarization Doppler radar data(C-Pol NUIST),radiosonde and surface precipitation. Convective cells echo are tracked using the TREC (Tracking Radar Echoes by Correlation) method. The changes of intensity echo ratio in the upstream and downstream of operation points are statistical. We analyze echo characteristics as reflectivity factor (dBZ), radial velocity(Vr), echo top height (ET), differential reflectivity factor Zdr and correlation coefficient of ?_hv. Atmospheric structure characteristics are analyzed with wind vector-potential temperature (V-30) plot. Research results show that the echo intensity and echo top are decreased within 30 min after operation. It has more strong rainfall in both short periods in intermittent of seeding catalyst and after operation. The study conclusion can provide the decision-making basis for the optimal operation time, the work place and the effect of artificial rain reduction.1. Using the cross correlation method to track the echo monomer, and the change of echo intensity ratio at the upstream and downstream of the operating point. It was found that the echo intensity was weakened after about 30 minutes, but the echo intensity was increased rapidly during the intermission.2. With the operation process of echo features of dual polarization Doppler radar reflectivity, radial velocity, echo top, differential Zdr and ?hv. It is found that the use of aircraft for warm cloud operation can affect the water vapor content in the middle atmosphere, but the effect of atmospheric 5km is not obvious.3.Analysis of the atmospheric structure characteristics of V-30 representation.The results show that the water vapor content in the atmosphere below 500hPa can be rapidly reduced after the rain enhancement operation and the rain reduction operation. After the continuous operation of the closing ceremony, it still has a certain impact on the strong echo, which can cause an empty area in the center of the strong echo area, so as to achieve the effect of reducing rainfall near the Olympic center.