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Show TABLE 13 Average Maximum Crystal Dimensions From 1967-68 Replica Se ri es I Crystal Type l ! Needle i I Avg. Max Dimensions (mm} o. Remarks 5 Stellars (Dendrites) 1.8 Unstructured Hexagonal Plates o. 3 Hexagonal Plates with Inner Stellar Structure 0. 1 Columns 0.4 Believed Associated with Seeding During 1968-69 riming frequently decreased .during calculated se e ding effect periods and subsequently increased again after the passage of the seeding effect. However, due to the problem of quantizing riming, plus the small data sample, no statistics are available on this apparent correlation between riming and seeding effect. 4. 3 Identification of Silver Iodide Nuclei in Ice Crystals As described in Section 2. 0, a technique was developed for detecting silver iodide nuclei in collected snow crystal replicas. Two hundred forty-five replica slides collected and analyzed by this technique during five seeding operations in 1968-69 were stratified into seeded and unseeded categories. Histograms of the percentage of individual crystal replica centers which grew microscopically visible AgI crystals during immersion in the AgI-KI solution were constructed (Figure 81). It is evident that significantly more crystal replica centers grew AgI crystals during se e ded, as compared to non-seeded periods. A "noise" level of near 10% appears to be present in in the unseeded sample. 133 |
