Cloud seeding is also referred to as weather modification. It is a process where we treat specific clouds or cloud systems to attempt to get more precipitation from the clouds. For centuries we have tried to control the weather. It may be the traditional rain dance or more scientific methods, but precipitation is a valued commodity. We seemed to have recognized that all through history.
Modern cloud seeding dates back to the late 1940’s. General Electric Labs had a working facility in Schenectady, New York. Quite by accident when doing another study they notice that dry ice shavings could be converted to super cooled water droplets. This observation led to a series of trials about what affects this could have on clouds and creating precipitation. Functioning cloud seeding programs began for commercial projects around 1950.
What are the most likely uses for cloud seeding? Many of us are familiar with seeding near airports. It can help disperse the fog and increase visibility so airplanes can be less hindered by weather conditions. It can help the storm remain heavy for a few minutes, but pass quickly.
Ski resorts need snow. Seeding the clouds in mountain areas where ski resorts are located is common place. They also use technology to “make” snow with machines. Enhancing the weather is big time business. It can make the difference between a record snow year and an average snow year.
Programs have been designed to help water districts so there can be water for crops and cattle. It helps to fill reservoirs. We can channel the participation to fall where it is most needed.
The most common agent used in cloud seeding is silver iodide. These particles are dispersed into the cloud formation, either by ground or airplane, to enhance the amount of moisture being released. If there is no cloud formationin which this process does not work. This is referred to as static cloud seeding.
Another form of cloud seeding is referred to as dynamic cloud seeding. This form of seeding concentrates on enhancing the vertical air currents in clouds. The vertical processing allows more water to move through the cloud and reach the ground. The same chemical is used but the delivery is different.
In Texas the results seemed very dramatic. The seeding increased the maximum height of the clouds by 7%. The areas of the cell were increased by 43%. The duration of the rainfall increased by 36% and the rain volume of the cells were at 130%.
Utah is the second driest state in the United States. There is probably more cloud seeding in this state than any other in the union. It’s a Mecca for the current study and controversy. There are concerns that areas “down wind” of the projects would not receive the normal amount of precipitation expected and that turns the issue into “water rights”, some thing that the western United States have been fighting about for years.
Very few companies are involved in cloud seeding. They are able to charge top dollar for their services and are required to be licensed. With the effects of global warming and other weather issues this is bound to become a more controversial process. in the mean time come join us in the high desert in Utah and enjoy the snow from the seeded clouds.
Sources:
www.weatherquestions.com
www.nawcinc.com
www.rams.atmos
