Abstract:
Based on the CINRAD/SA radar observations in Beijing and Tianjin, the radar echo evolution characteristics of convective cells A and B in a severe convective storm affecting Beijing on 30 June 2021, are analyzed herein. The variation in various physical parameters and the number of grid points of different reflectivity intensity grades in different stages of cell development are analyzed before and after operation in the statistical area, obtaining the evolution characteristics of cells with different strengths under different operating conditions. The results show that cell B is a normal convective cloud cluster (lifetime=3 h). After the large dose operation (74 rockets and 58 antiaircraft guns are effectively operated within 24 min) in the early stage of development, cell B has good characteristics of inhibiting cell development. Parameters such as mean reflectivity, storm body height, and vertically integrated liquid water at different heights of the storm body show a downward trend. The number of grid points of the stronger echo (30–60 dB
Z) and the weaker echo (20–30 dB
Z) decreases and rapidly increases, respectively, and the convection structure weakens overall. Cell A is a supercell (lifetime=5.5 h), and no obvious inhibition effect is apparent in the initial stage because of an insufficient operating dose (15 rockets are effectively operated within 30 min). Near the mature stage, continuous high-dose operations are performed (105 rockets and 182 antiaircraft guns are effectively operated within 80 min). Although characteristics similar to echo B are also observed, the average reflectivity, cloud top height, strong echo thickness, vertically integrated liquid water, and other parameters in the upper layer decrease; further, the number of grid points decreases in the higher-reflectivity intensity range (50–70 dB
Z) and increases and lasts for approximately 30 min in the lower-reflectivity intensity range (30–50 dB
Z). However, the overall work suppression effect on supercell A is subtle.