Use of an acoustic ice nucleus counter to map surface-based seeding plumes in Wyoming

An acoustic ice nucleus counter is being flown on a Weather Modification, Inc. (WMI) Piper Cheyenne II cloud physics and seeding aircraft in the context of the Wyoming Weather Modification Pilot Project (WWMPP) during the winter of 2007-2008. In visual meteorological conditions under mid-level or high overcast, it is possible to fly sufficiently low to transit ice nuclei plumes produced by the project's ground-based generators. The characteristics of these plumes will be quantified, and the results summarized. Of specific interest are the horizontal and vertical extent of the plumes in various wind and stability conditions, and the ramifications of these findings on effective targeting. Also of interest is the potential transport of seeding agent from the more western Sierra Madre Mountains to the Medicine Bow Mountains to the east, as the latter range is downwind of the former during many precipitation events, yet the upwind range may be the range selected for treatment (seeding).