Cloud seeding has been used for some time. But new developments could make it rain when we want it very soon — and that could change the world as we know it.
What if it were possible to make it rain whenever we want?
In a new study, researchers at TU Wien (Vienna University of Technology) mapped out how silver iodide initiates ice formation at the atomic scale.
The key number is 24.8 degrees Fahrenheit, or -4 degrees Celsius—a temperature at which silver iodide can initiate freezing in supercooled clouds.
Cloud seeding adds tiny particles of silver iodide to clouds from airplanes to encourage ice formation.
“A cloud seeding It is an approach used for decades to modify atmospheric weather and involves a series of supporting technologies for research and operations,” stated the US Government Accounting Office in a 2024 technical report, cited by .
The new experiences described in the Science Advances used non-contact atomic force microscopy (NAFM) — a method that obtains iimages of atoms detecting tiny forces without touching them. Measurements were carried out at cryogenic temperatures to keep the atoms fixed.
“These findings highlight the decisive role of the atomic structure of the surface and indicate that the silver-terminated basal plane is primarily responsible for the efficient nucleation of ice in AgI,” wrote researcher Jan Balajka, who explains why one face works and the opposite blocks growth.
The practical conclusion is clear for Material Design: To create better ice starters, you need to adjust surfaces that maintain the correct atomic spacing and encourage the orderly formation of water layers. We are getting closer and closer to being able to make it rain — and change the climate anywhere in the world.
