Precipitation change from a cumulonimbus cloud downwind of a seeded target area

Abstract

A silver-iodide seeding agent was released, which may have resulted in enhanced precipitation over 100 km downwind from the point of release. This study attempts to determine whether this enhancement occurred. It is not possible to quantify the amount of precipitation that would have been released from an unseeded cloud if it has already been seeded, since no two clouds are alike. As a result, numerical models remain the best tool to investigate the effects of cloud seeding. We use a three-dimensional mesoscale cloud-resolving model, and we simulate seeding of a region with temperatures below 0°C in front of a target cloud that might lead to a change in cumulative precipitation far from the initial seeding area. Our model simulations show that this cloud seeding enhances cumulative precipitation 110 km from the center of mass of the initial seeding area by about 50%. Copyright 2008 by the American Geophysical Union.