It’s a weather modification technique that artificially re-creates how clouds naturally create rain and snow. Normally, tiny droplets of water vapor in a cloud are attracted to things like dust, pollen or salt from the sea, which act as nuclei. When enough of these microscopic water droplets converge around these nuclei, they form ice crystals and are heavy enough to fall, creating precipitation. Without nuclei, ice crystals cannot form, which means there won’t be any precipitation. But scientists discovered that ice crystals formed instantly around particles of silver iodide. Cloud seeding essentially helps trigger this process in order for it to rain. Many times planes are dispatched and inject particles, like silver iodide, into clouds in the early stage of their formation to encourage rainfall.
