A Suggestion of Verification Method for Cloud Seeding Experimental Results via Analyses of Chemical Components of Precipitation

Abstract In an attempt to minimize the adverse impacts of rapid climate change, such as forest fires and droughts, the development of cloud seeding technologies has increasingly attracted attention. However, the effects of cloud seeding have not been verified directly. In the present study, chemical analysis of precipitation samples was explored as a method of confirming the case-by-case effects of cloud seeding experiments. Hourly precipitation samples were obtained using automatic precipitation collectors placed in seeded/nonseeded areas, which were calculated in advance by numerical methods. To directly confirm the effects of cloud seeding, analyses of ionic and heavy metal components (nonsea salt Ca 2+ and silver) of the samples were carried out. Three aviation experiments are presented (CaCl 2 , NaCl powder and CaCl 2 , AgI flare seedings). Each result demonstrated a noticeable increase in the main seeding materials at the rain sampling points within 1–3 h after the experiment, as confirmed by a numerical model. Although a small number of cases were considered in this study, our hourly analysis method highlights the potential for direct and rapid verification of cloud seeding experiments.