Laserfiche WebLink
<br />After the first year, field investigations in other locations will focus <br />on selected winter and summer cloud systems and will emphasize dynamically <br />evolving clouds, especially those involving secondary ice production <br />processes. The approach is physical rather than statistical, and the program <br />is not tied to a particular type of cloud system. As many of the studies as <br />possible should to be carried out as add-ons to full-scale cloud and weather <br />modification investigations in progress at the time. This approach will <br />permit t~he' versatility of in-depth studies of different cloud systems without <br />much of the logistical and support work and expenditure required of stand- <br />alone field studies. Project design will be tailored in each case to the <br />selected cloud system. Thus, while the objectives remain as stated above, <br />approaches and techniques will evolve with the program. <br /> <br />Beginning approximately in the third year, small-scale cloud s~eding will <br />be conducted to manipulate and observe changes in selected ice processes. <br />Results from the first years will be utilized to design these experiments. <br />Overall analyses and integrated interpretations of observational, laboratory, <br />and modeling data and outputs from anyone year will continue in subsequent <br />years of the program. <br /> <br />(2) Geographic Variability of Precipitation Efficiencv Program. This <br />proposed NOAA program ,seeks to investigate natural precipitation processes in <br />various cloud types and geographical regions in terms of precipitation <br />efficiency. Precipitation efficiency is defined here as the ratio of the <br />total ground-level precipitation to the total water condensed for a particular <br />cloud system. <br /> <br />Program objectives include description of the geographic variability of <br />precipitation efficiency of clouds, identification of the factors that <br />determine precipitation efficiency, and ultimately, use of these factors to <br />assess the seedability, or modification potential, of clouds in different <br />seasons and geographic regions. A 10-year research program will progress from <br />an emphasis on analysis and numerical modeling in the first years, through <br />periods of intensive measurements and field experiments, to a synthesis of <br />information on those factors that govern the production of precipitation. It <br />will make the greatest possible use of data from past and ongoing field <br />projects. It will maintain its focus on the potential for artificially <br />manipulating the precipitation process. <br /> <br />The first-year program will have three major components; analysis, <br />modeling, and observation. Analytical studies will focus first upon <br />summertime cumulus congestus clouds, partly because they a~ist as separate <br />entities (as opposed to a more general rNintertime storm) and partly because a <br />larger data base exists for this type of cloud. Previous and ongoing research <br />programs of special interest include Project ~~itetop (1960 to 1964), a <br />National Science Foundation sponsored project in central Missouri; the Florida <br />Area Cumulus ~~periment (FACE--1970 to present); and the High Plains <br />Cooperative Program (HIPLEX--1973 to present). The sto~scale component or <br />the Se'Tere Environmental StOelS and ~1esoscale Experiment (SESAJ.'1E), conducted <br />in Oklahoma during the spring of 1979, offers another data set. Analysis ot <br />these and other data sets from the fresh perspective of precipi:ation <br /> <br />- 39 - <br />