When drought dries out the land, the clouds, full of water, that hover over the landscape and dump their moisture elsewhere are especially frustrating. If only they would rain! And after decades of cloud-seeding attempts, the most extensive study of its effects has just come up with some answers about how well that might work, writes Dave Zook for High Country News.
The basic idea behind cloud seeding is that rain needs particles, or nuclei, to condense around before it can fall. Often those particles are dust in the atmosphere. We artificially seed clouds by releasing microscopic particles of silver iodide into storms using generators on the ground or airplanes. The idea fires people up: Rainmaking is practiced around the world and was investigated as a weapon in the Cold War.