Ascent of Surface-Released Silver Iodide into Summer Convection Alberta 1975


  • James A. Helmbach Institute of Natural Resources
  • Newton C. Stone Irvlng P. Krlck Associates Canada, Ltd.


During the summerof 1975, an experiment was conducted near Calgary, Alberta, Canada,to test the hypothesis that surface-released silver iodide can reach the inflow regions of cumulonimbus clouds. Effluent from point and quasi-area sources of Agl impregnated coke-fueled generators were traced using airborne NCAR Ice nucleus counters. The evidence shows that it is possible for plumes to ascend to give concentrations to up two orders of magnitudeabove background -20 °C (>200 at nuclei per liter) In cloud-base Inflow areas. Targeting was difficult and the horizontal disperslon the plume less of than anticipated. Ice nucleus concentratlons were usually above background levels to the top of the mlxlng layer. Three case studies having relevance to the application of ground-based Agl generators are dlscussed and a summary of flights during convective periods given.






Scientific Papers