Research on a hailstorm process in Chongqing based on multi-source observation data
In order to understand the thermodynamic evolution characteristics of the convective system before and after the occurrence of hailstorm,and strengthen the application of new detection data in hailstorm monitoring and early warning,a strong hailstorm weather process occurring in the western of Chongqing in the early morning of April 18,2014 was analyzed by using the observation data of mi-crowave radiometer,wind profiler radar and Doppler radar.The results show that the hailstorm process was a typical strong convective weather forced by low-level warm advection,and the radar echo overhanging characteristics and radial velocity convergence were obvi-ous.Before the occurrence of the hailstorm,the temperature and humidity retrieved by microwave radiometer data increased signifi-cantly.From 1.0 to 3.0 hours before the occurrence of hailstorm,K index,850 hPa and 500 hPa pseudo-equivalent potential tempera-ture differenc(θse850-500),CAPE(Convective Available Potential Energy),vertical wind shear from 0 to 3 km(SHR0-3)etc.increased sig-nificantly with time.The atmospheric refractive index structure constant(Cn2)increased to its peak within 0.2 to 0.5 hours before the oc-currence of hailstorm,and the vertical velocity observed by wind profile radar in middle and lower layers,fluctuated significantly with height.The commonness of the parameters of multiple hail processes show that the brightness temperature of 25.00 GHz,Cn2 and the area of atmospheric refractive index structure constant(SCn2)of microwave radiometer had a significant increase trend within half hour before the occurrence of hail,and SCn2 was greater than the threshold of-500 dB·km within 10 minitutes before the occurrence of hail-storm.The vertical integral liquid water and the vertical velocity difference from the ground to the high altitude reached the maximum when the hail fell on the ground,and the Cn2 jumped to the threshold value of-120 dB in the middle and low layers.All the characteris-tics mentioned above have a good indication for identifying the occurrence of hail.
万方数据
维普
