Study on the Mechanism of Anti-Hail by Explosion Based on X-Band Dual-Polarized Phased Array Radar

Hail is a significant meteorological hazard in China, particularly during spring and summer, causing extensive damage to agricultural production. Anti-hail artillery has been widely used to mitigate hail damage, but its physical effects have not been well-supported by field observations. This study evaluates the physical impacts of anti-hail explosions using high-resolution, rapid-scanning X-band dual-polarized phased array radar data from an anti-hail artillery operation in Linfen, Shanxi. The results show that radar reflectivity, differential reflectivity and specific differential phase are not highly sensitive to the effects of explosions, but radar reflectivity can indicate cumulative changes in the cloud structure. In contrast, radial velocity, spectral width and correlation coefficient can effectively reflect the effects of explosions, showing decreased radial velocity, increased spectral width, and decreased correlation coefficient around the explosion site. The variation of correlation coefficient indicated that the horizontal impact range of the explosion was approximately 1 km, while the vertical impact extended around 1.5 km. Continued artillery operations led to a rapid decrease in the 45 dBZ echo top height of the hail cloud, and a Relatively Weak Echo Region (RWER) formed beneath the explosion site, which was surrounded by descending strong upper-level echoes and the lower-level strong echoes. Hydrometeors near the explosion site transformed from graupel to dry snow, effectively reducing the availability of hail embryos.