Validation of Cloud Seeding using the Airborne Radar

In many cloud seeding programs, the effect of cloud seeding in natural situation has been statistically verified by analyzing the long-term variation of precipitation between experimental and control region. The case analysis for each cloud seeding experiment is needed for the advance of seeding technology, but is avoided because of the limitation of existing instruments. One of the preferable instruments for the validation of cloud seeding is the ground based radar(s) because of its good spatial and temporal resolution, but it also has the limitations of cloud observation such as the geometric darkness by earth curvature far from radar site. Using the airborne radar, we have obtained the results that the radar reflectivity is evidently enhanced along the wind direction from the seeding path about 15 minutes after seeding at 4 March 2008. This suggests that the advanced sensor system such as the airborne radar may facilitate the case-by-case validation of cloud seeding experiment, as mentioned in the Garbor Vali's talk in the 2007 WMO conference, and the detailed understanding and rapid progress of weather modification research and operation (Most of cloud seeding project, based on the statistical verification, need the longer period than 5 years).