New Study Quantifies Ice Formation from AgI Cloud Seeding
A paper by Anna J. Miller et al. was recently published in Atmospheric Chemistry and Physics and selected as a Highlight Paper for its innovative approach and important findings.
In the study "external page Quantified ice-nucleating ability of AgI-containing seeding particles in natural clouds", we discovered the first field-based quantification of how silver iodide (AgI) particles induce ice formation in supercooled clouds under real atmospheric conditions. To achieve this, we released AgI-containing seeding particles from an uncrewed aerial vehicle directly into low-level supercooled stratus clouds. Downwind, a tethered balloon measured the ice crystals formed as a result of the seeding.
Our unique observations allowed us to identifythe freezing mechanism. The particles first grow hygroscopically into solution droplets, which then freeze and develop into ice crystals. Importantly, our data rule out competing processes like contact freezing, providing a clearer understanding of how AgI particles influence cloud glaciation. This discovery offers valuable insights that could improve the effectiveness and predictability of cloud seeding techniques in weather modification efforts.