A Three-Dimensional Modeling Study of Hailstorm Seeding


  • Vlado Spiridonov Hydrometeorological Institute Skopje, Macedonia
  • Mladjen Curic Institute of Meteorology University of Belgrade, Serbia


A three-dimensional cloud model is used to simulate transport and diffusion of an artificial ice nucleation agent in conditions of hypothetical hailstorm seeding. The microphysical parameterization use the bulk a second-moment scheme for all species. According to the beneficial competition criteria, silver iodide is directly injected andreleased into an assumed embryo formation region, between -8 degrees C and -12 degrees C isotherms and 25-45 dBZ radar reflectivity contours on line with length of 1.5 km. The results from the case study simulation have shown that agent typically has about 2-3 min to spread in the seeding zone after its activation and relatively low vertical extension of spreading from the axis of dispersion, which is less than 160 m. The agent activation leads to earlier ice initiation that causes earlier initiation of precipitation. The implication of the seeding is that cloud seeding with a 6 min time frequency contributes in registration of the maximum hailfall decrease at the ground of about 11.01%, compared to the unseeded case. The maximum rainfall increase of 25.79% and hailfall decrease of 10% is found in the experiment with 0.4 g/m initial seeding rate, 5.5 km seeding height and 10 km seeding distance, compared to the base run simulation, respectively.




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