Abstract
This study conducted numerical experiments of heavy rainfall mitigation under multiple
experimental conditions using the Weather Research and Forecasting model (WRF) to investigate
the effectiveness of Pinpoint-Seeding operation in linear convective systems. By examining the
difference of mitigation effects among different seeding methods and implementation conditions,
it was found that implementing Pinpoint-Seeding only in grids with strong updrafts resulted in
a reduction of approximately 16.5% in maximum accumulated precipitation. This study also
clarified the impact of seeding duration and implementation altitude on the mitigation effects.
The mechanism of rainfall mitigation through the over-seeding condition, where the growth of
ice crystals and snow reduces supercooled water droplets and then suppresses graupel growth,
was confirmed by analyzing mixing ratio and number concentration of precipitation particles.
