Every Cloud Has a Silver-Iodide Lining

Santa Barbara County to Spend $370K on Cloud-Seeding Program to Maximize Rainfall over Next Three Months

Airplanes are one of two methods of impregnating fertile cloud formations with raindrop-inducing silver iodide. | Credit: Courtesy

With most of California now entering the fourth year of drought and the state’s major reservoirs starting to display bathtub rings where water used to be, the Santa Barbara County Board of Supervisors voted to spend $370,000 to dope passing rain clouds with silver iodide to better get every drop of rain possible.

The least risky, simplest method of delivering silver iodide into passing rain clouds is launching it in flares from ground-based locations. Last year, 82 flares carrying 1,312 grams of silver iodide were launched. | Credit: Courtesy

Cloud seeding, as it is known, dates back to 1950 in Santa Barbara, but the county’s Water Agency has been involved in the program since 1981. The money will go to a private contractor — North American Weather Consultants — which in turn will launch the silver iodide into fertile cloud formations over the next three months either by dropping it out of airplanes or launching flares from ground-based locations. Of the two methods, the latter is the least risky and simplest to do.

The trick, according to Matt Scrudato of the County Water Agency, is to impregnate clouds already laden with potential rain. Cloud seeding, he stressed, can’t create rain where it wouldn’t otherwise fall. Instead, he explained, it increases the amount that manages to drop to the ground.