Wet deposition of the seeding agent after weather modification activities.

Weather modification activities are performed mostly by cloud seeding. Some operational projects have been conducted for more than a half century and cover planetary scales. These activities have led to large amounts of seeding agents being deposited on the ground in precipitation. The main intent of this paper is to identify the spatial pattern of silver iodide deposits after hail suppression. The spatial pattern of silver iodide deposits is determined using the weather modification project measurements from seeding agent reports, two weather radars and 316 launching sites during a 5-year period. The estimated spatial distribution of the deposits is not uniform, with the maximum silver iodide amount located in the southern part of the study area (up to 140 μg m(-2)). Our results are comparable with the measurements performed by chemical analyses during other cloud seeding experiments. The maximum location coincides well with that of the maximum seeded hailstorm precipitation frequency. A new method for identifying the spatial pattern of wet-deposited material has been established. The location with the maximum amount is found. This method would be important as a means of placing samplers and monitoring at the representative sites because those are where most weather modification projects would be performed in the future.