The Impact of Glaciogenic Seeding on Orographic Cloud Processes: Preliminary Results from the Wyoming Weather Modification Pilot Project


  • Bart Geerts Department of Atmospheric Science, University of Wyoming
  • Qun Mia Department of Atmospheric Science, University of Wyoming
  • Yang Yang Department of Atmospheric Science, University of Wyoming
  • Roy Rasmussen Research Applications Laboratory, National Center for Atmospheric Research
  • Barry Lawrence Wyoming Water Development Office


Cloud seeding has long been and remains the most widely practiced method of advertent weather modification (Qiu and Cressey, 2008). It is remarkable that notwithstanding all the data collected and the high level of experimental control compared to typical research on cloud and precipitation processes, the effectiveness of cloud seeding in enhancing precipitation remains uncertain (Bruintjes, 1999; National Research Council, 2003). Numerous statistical studies have been conducted to assess changes in surface precipitation, often with mixed or questionable results. The level of noise in natural systems compared to the magnitude of the signal makes verification of precipitation enhancement extremely difficult (Garstang et al., 2005). Numerous studies and reports have pointed to the need for field measurements that document the cloud microphysical "chain of events" that lead to an alteration of surface precipitation




Technical Notes and Correspondence