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<br />Cloud Simulation and Aerosol Laboratory at Colorado State University (fig. 2.2), the EJ-20 <br />and the modified TB-1 flares produce about 3 x 1014 and 8 x 1014 ice crystals per gram of <br />AgI, respectively, at -10 oC. Both flares yield about 1013 ice crystals per gram of AgI at -5 <br />oC. <br /> <br />The EJ-20 flares will be ejected in Thailand at the seeding flight altitude (normally 21,500 <br />feet) from the project AeroCommander 690B turbo-prop aircraft. Drop temperature should <br />be < -7 oC. When ejected at seeding altitude, each fla:re normally burns for at least 50 <br />seconds and falls more than 1.5 kilometers in still air; The fall distance obviously will not <br />be as great in strong updrafts. The seeder aircraft Will carry a maximum of 200 20-gram <br />flares on each flight. <br /> <br />Sax et al. (1979) showed that on-top seeding with AgI flares produces glaciation along the <br />lines required by the conceptual model. What constitutes intensive seeding has evolved over <br />the years. In experiments over the Caribbean in 1965 and 1967, some tropical ~louds <br />received up to 34 kilograms of Agl. In. Florida, the amount of AgI per cloud had dropped to <br />0.5 to 1.0 kilogram, and in Texas the amount was generally less than 0.5 kilogram... <br /> <br />In the Thai experiments to date, the average flare expenditure per cloud pass has been 5 <br />flares, or 100 grams of Agl. This amount will likely be the seeding rate during the <br />demonstration project. <br /> <br />Distribution of AgI, and not its total amount, appears to be the most important consideration <br />in conducting on-top seeding. An amount of AgI has not been specified in the conceptual <br />model for this reason. T~e duration of seeding and the amount of nucleant that is expended <br />in each experimental unit will be lmlimited. Seeding will continue as long. as cloud <br />conditions are suitable. <br /> <br />2.9 Experimental Procedures <br /> <br />2.9.1 Forecasting procedures <br /> <br />Implementation of forecasting procedures is a design element that is common to all cloud <br />seeding programs. Forecasting is done to eliminate unacceptable days in advance so that <br />precious resources are not wasted on unsuitable weather conditions. Forecasting will be an <br />important component of the Thai demonstration project, as is obvious from the forecasting <br />procedures to be implemented in the efforts described in "Volume 3 - Demonstration Project <br />Operations Plan." The output of sim]ple cloud models that have been calibrated previously <br />by comparison with observations is vital to the forecast. How this has been done for Thailand <br />is described in appendix C. <br /> <br />2.9.2 Flight procedures <br /> <br />The flight and seeding procedures to be implemented in the Thai demonstration project will <br />be identical to those that were executed in the exploratory experiments described in appendix <br />B and in the Operations Plan that is presented in Volume 3 of this Final Report. The same <br />procedures will be applied to both seeded and non-seeded experimental units, except seeding. <br />will be simulated in those units that have randomly been assigned the NS decision. <br /> <br />11 <br />