The AgI Seeding Cloud Impact Investigation (ASCII) campaign 2012: overview and preliminary results
Keywords:glaciogenic cloud seeding, Weather Modification Research
AbstractThe ASCII campaign was conducted in early 2012 over the Sierra Madre, a Continental Divide range in Wyoming, to examine cloud microphysical changes resulting from the ground-based injection of silver iodide (AgI) into shallow orographic clouds. The campaign included a dual-polarization Doppler-On-Wheels radar on the mountain pass, the University of Wyoming King Air aircraft with profiling mm-wave radar and polarization backscatter lidar, two Ka-band profiling radars, one upstream of the AgI generators, and one downstream, and a number of instruments on the ground to characterize the cloud liquid water content and the in situ snow particle characteristics. The experimental design supported both simultaneous (upstream/ downstream) and non-simultaneous (before/ during) comparisons, in order to tease out the impact of glaciogenic seeding on cloud and precipitation. Unfortunately, suitably cold cloud base temperatures rarely occurred during the campaign. Nevertheless, profiling radar data collected on flights with a no-seeding period followed by a seeding period, as well as simultaneous ground-based profiling radar data, indicate that under suitable conditions AgI seeding can significantly increase radar reflectivity in the boundary layer, and thus snowfall rate near the ground.
Authors that submit papers for publication agree to the Journal’s copyright and publication terms. Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution License that allows others to share the work with an acknowledgement of the manuscript’s authorship and initial publication in Journal of Weather Modification. Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal’s published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgement of its initial publication in the Journal of Weather Modification. Authors are permitted to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process to encourage productive exchanges and greater citation of the published article.
Articles are published online using restricted access for the first year. After the first year, articles are made freely available online. Immediate open access for an article may be obtained by the author paying an open access fee which is in addition to the normal page changes. Authors are expected to honor a page charge in order to support publication and distribution of the journal. After the author approves the gallery formatted version for publication, the Weather Modification Association’s Secretary will invoice the corresponding author for the page charges and payment is due within 30 days.