Seeding clouds to produce precipitation

Dr. Vincent Schaefer undertook the first weather modification experiments for General Electric in 1946. Cloud seeding companies use aircraft or ground generators to release silver iodide particles into clouds when temperature and moisture are ripe for rain. Attracting clumps of moisture, the silver iodide particles trigger formation of ice crystals which then fall as additional rain or snow.

Cloud seeding requires that cloud contain enough moisture for the silver iodide crystals to tip near-saturation into rain or snow.

Estimates of increases in precipitation resulting from weather modification programmes range from 10 to 15 percent over normal rainfall in the wintertime northern hemisphere areas to as much as 25 percent in tropical regions.

1. A U.S. Air Force research study, "Weather as a Force Multiplier" outlines how powerful "ionospheric heaters" and clouds generated by chemical condensation trails - contrails - spread behind airborne tankers could allow U.S. aerospace forces to "own the weather" by the year 2025.

1. Lawsuits have been made by litigants claiming to be harmed by floods resulting from weather modification.

1. Modifying the weather
2. Improving reliability of rainfall
3. Augmenting present water supply

1. Supplementing seasonal rain supply

1. Unethical practice of meteorology
2. Destructive techniques for weather modification