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<br />Gagin, A., D. Rosenfeld, W. L. Woodley, and R. E. L6pez, 1986: Results of seeding for dynamic effects on
<br />rain-cell properties in FACE-2. Journal of Climate and Applied Meteorology, 25:3-13.
<br />
<br />V olume scan radlar studies incorporating the use of an elaborate method of defining and tracking
<br />convective rain cells through their lifetime have been used to:
<br />
<br />(a) Explore and verify, in quantitative tenns, the basic tenet of the technique of cloud seeding aimed at
<br />producing dynamic effects. This technique relates increases in the depth of convective cells, assumed to
<br />occur due to this type of seeding, to corresponding increases in the treated cells' rainfall intensity, area
<br />and duration of precipitation, and consequently, to the total yield of rainfall volume.
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<br />(b) Employ the data gathered on the gross properties of rainfall of convective cells, namely their
<br />heights, intensitil~s, precipitation areas and their durations and total rain volume, to estimate the effect of
<br />seeding, if any, on their properties.
<br />
<br />These studies suggest that seeding convective cells for dynamic effects affected the preceding properties
<br />of these cells in a manner that resulted in increases in their total rainfall and that the positive changes
<br />in these properties could be predicted from the changes in maximum cell height following seeding.
<br />
<br />The effect of see:ding appears to be strongest for cells treated early in their life cycle with a substantial
<br />amount of AgI (i.e., more than 600 g). Seeding effeclts of 22% increases in cell heights and over
<br />100% increases in cell rain volume are indicated under such seeding conditions. The significance levels
<br />of these results are found to be 2.1 % and 0.6%, respectively.
<br />
<br />The positive effects produced by seeding on the AgI treated cells may have resulted in a compensating
<br />negative effect on the smaller untreated clouds fonning in the vicinity of these treated cells.
<br />
<br />Garcia, P., S. A. Changnon, and M. Pinar, 1990: Economic effects of precipitation enhancement in the
<br />Com Belt. Journal of Applied Meteorology, 29:63-75.
<br />
<br />Policy formulation in weather modification requires an understanding of the economic effects from
<br />altered weather. The focus of this study is to provide insight into the beneficiaries of a functioning
<br />weather modification technology when applied at various spatial and temporal levels. An econometric
<br />model which links the com/soybean production to U.S. cattle, hog, and poultry sectors is used to
<br />detennine the effects of precipitation enhancement in the U.S. Com Belt, a humid climatic region. A
<br />regional supply fonnulation pennits assessment of weather modification on production, prices, revenues
<br />to producers, and savings in consumers expenditures on meat. The results provide insight into the
<br />distribution of economic effects, emphasize the imporltance of careful planning in the use of weather
<br />modification technology, and provide useful infonnation on the roles of local, state, and federal
<br />governments in lbe support of weather modification.
<br />
<br />Garcia, P., S. E. Offutt, M. Pinar, and S. A. Changnon, 1987: Com yield behavior: Effects of technological
<br />advance and weather conditions. Journal of Climate and Applied Meteorology, 26: 1092-1102.
<br />
<br />This study explores the relationships between U.S. corn yields (level and stability), advances in
<br />technology, and weather. Evaluations at the fann, sub-state, and national levels reveal no evidence of
<br />yield plateaus, and absolute, but not relative, yield vaJiability increased over time. When yield behavior
<br />is adjusted for weather, variances are more likely to be equal between early and late periods. Results
<br />suggest that technology has not been the only detenninant of changing yield risk, and emphasize the
<br />importance of weather conditions in assessing these elIects.
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