Winter has rolled in. Both mountains and yards are covered in snow.
For most, this means making sure the car and house is winterized, planning for traveling to take longer than average, placing the snow boots by the door, ready for use.
For Larry Hjermstad, owner of Durango-based Western Weather Consultants, it means cloud seeding.
Hjermstad operates cloud seeding programs in several areas in Colorado, with 34 generators in the San Juan Mountains. One program is located in Pagosa Springs and is known as the Four Mile Creek Weather Modification Program, which consists of four strategically placed generators.
The generators operate by vaporizing silver iodine and sending it to the clouds.
Hjermstad says that for clouds to be effectively seeded, several weather factors must occur: 1) the weather system must hold for a minimum of six to seven hours; 2) winds must be strong enough to carry the silver iodine to the clouds’ higher regions where ice crystals naturally occur; 3) there must be enough moisture; 4) target cloud temperatures for 10,000 feet elevation would be 22 to 25 degree F, the coldest the temperature could drop would be 0 degrees; 5) the cloud system must lie low enough for the silver iodine vapor to reach and materialize in the cloud system.
“The silver iodine needs to be cold enough to attract moisture to grow on it,” Hjermstad said.
With a recent storm, Hjermstad says the response was an 8- to 10-percent increase in precipitation.
So far this winter season, Hjermstad says the generators in the Pagosa area have been activated three times, the last time for a period of three days.
The San Juan Water Conservancy District (SJWCD) paid $2,080 to Hjermstad’s firm for cloud seeding in 2011. For 2012, SJWCD has budgeted $1,875. Pagosa Area Water and Sanitation District (PAWSD) has budgeted $5,200 for 2012.
This amount qualifies both SJWCD and PAWSD as standby participants of the Fourmile Creek Weather Modification Program. However, Hjermstad said that their funds, with those from the Southwest Colorado Water Conservation Board and the Lower Basin States (Arizona, California and Utah), has enabled the generators to be operational until the end of December. If more funding comes in from the Lower Basin States, Hjermstad anticipates operating the program until mid-January.
Though cloud seeding, or weather modification, seems to be something highly technological, it is not a 21st century invention. Early forms of cloud seeding were seen in the late 1940s when Vincent Schaeffer conducted a set of experiments in the General Electric laboratory which resulted in the discovery that dry ice has the ability to convert very cool droplets of water into ice crystals.
However, the most commonly used chemical for seeding the clouds is silver iodine. The discovery that led to using this chemical is contributed to Dr. Bernard Vonnegut, brother of writer Kurt Vonnegut. (Kurt Vonnegut used a similiar crystallizing agent, the fictional ice-nine, in his novel “Cat’s Cradle” to destroy the world by turning all oceans’ water to ice.)
It was a relatively short time later, in 1965, that the San Juan Mountain region had attracted cloud seeding scientists. By 1970, Hjermstad was a part of the Bureau of Reclamation’s cloud seeding study which took place between 1970-1975 in the San Juan region.
Hjermstad has been seeding clouds in the Pagosa region on and off since 1976. “This has been a very exciting and rewarding life-long occupation,” Hjermstad said.
According to Hjermstad, Pagosa seeding efforts took place between 1976 and1980. Pagosa Country turned its eyes again to the clouds in 2002 during the severe drought the area and all of southwest Colorado were experiencing. At that time, offcials representing Archuleta County, Pagosa Springs, Southwest Colorado Water Conservation District, San Juan Water Conservancy District, Pagosa Area Water and Sanitation District, as well as the Pagosa Springs Golf Club and Wolf Creek Ski Area, all began to think of the possibility of increasing precipitation through cloud seeding.
Whether or not cloud seeding works or is cost-effective is still a debated matter, yet, worldwide, various weather modification systems and programs are still being pursued. Perhaps the most notable was the 2008 Olympic Games in China, during which the government came through on its promise of no rain.