Laserfiche WebLink
<br />recognize that seedability depends on a number of different meteor- <br /> <br /> <br />ological and topographical conditions such as cloud moisture, cloud <br /> <br /> <br />top temperature, and wind speed. However, it is not sufficiently <br /> <br />clear how these interact with each other in different locales and <br /> <br /> <br />the relative importance of each. <br /> <br />A large data base is available from field projects with which <br />seedability criteria can be studied. Randomized winter orographic <br />cloud seeding projects have been conducted extensively in the <br />Western United States from the Rocky Mountains to the Sierra and <br />from New Mexico to the State of Washington. Mountain barriers of <br />many shapes and sizes have been used as target areas. Deep clouds, <br />shallow clouds, stable clouds, clouds with embedded convection, <br />warm clouds, cold clouds, moist clouds, relatively dry clouds, <br />clouds with strong winds, clouds with light winds; many possible <br />combinations of clouds have been seeded. <br /> <br />Attempts should now be made to integrate results from several of <br /> <br />these projects into a comprehensive set of seedability criteria. <br />Along these lines, Grant and Elliott [3] looked at cloud top tem- <br />perature. After adjustments were made for cloud height differences <br />among the projects studied, a general cloud top temperature "window" <br />was found to exist in which seeding increased precipitation. Such <br />studies are needed for many other variables. <br /> <br />2 <br />