Effects of Cloud Seeding on Air Quality and Particulate Matter Dynamics: United States, China, and United Arab Emirates case studies

Space-Borne and ground-based data are used to investigate the environmental effects of cloud seeding on air quality and Particulate Matter (PM2.5 and PM10) dynamics. Seven sites in United States (Texas, Wyoming, California, Idaho, Utah, Nevada, and Montana), two sites in China(Henan and Fujian Gutian), and one site in the United Arab Emirates (Abu Dhabi) are considered for this work. Long-terms statistical analysis of aerosol optical depth (AOD), Ångström exponent(AE), precipitation, and particulate matter is performed. Meanwhile, meteorological data including temperature, humidity, pressure, and wind speed/direction are analyzed. Air quality conditions before, during, and after cloud seeding missions are tested using ground monitoring stations. Data from the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the Terra were also used to perform a statistical correlation between aerosol optical depth (AOD) and ground PM observation. An increase in PM concentration was observed during cloud seeding missions’ period, which indicates a possible effect of silver iodide crystals fired during the missions in increasing the concentration of PM in air. The study found that cloud seeding missions have a possible effect on increasing PM10 compared to PM2.5 concentration, which point to the possible effect of meteorological conditions on washing out silver iodide particles fired during the missions.