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Show 3. 2. 1. 5 Summary Adequ ate determination of nuclei distribution from ground based generators in mountainous terrain requires a complete high resolution time and space analysis of flow conditions and temperature stratification. Even given an accurate description of ambient conditions, the actual distribution of seeding agent cannot be adequately controlled. The treatment is largely at' the mercy of very localized conditions. Significant vertical dispersion is completely stopped by any inversion above the release level and seriously slowed by any stable layer (see Table 7). TABLE 7 VERTICAL DISPERSION OF SILVER IODIDE PLUME Test No. Daisy 6 Daisy 46 Daisy 52 Stability (Lapse Rate) Neutral or Unstable " Inversion (very stable) Distance From Source (n. mi. ) Vertical Dispersion (ft. ) Source Altitude (ft. MSL) 3.0 3300 8200 2. 5 3600 7400 5. 0 300 8200 Horizontal dispersion is related to the horizontal wind fluctuations in neutral and unstable cases. Plume widths can be either very narrow or very wide under stable conditions. An example is Daisy 37 (Figures 47a and b) where the material was spread over a broad area at 8, 000 ft. MSL and was very narrow at 8, 500 ft. MSL. Regarding the maintenance of discrete pulses by the atmosphere, the tests cover a wide spectrum of conditions. Under neutral stratification through a deep layer the pulsed characteristics of a periodic release are strictly maintained at elevations well above terrain (e. g. Daisy 42). Under very stable conditions the material trapped in an inversion layer can act as a continuous source of material for periods on the order of an hour or longer, and any 81 |