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<br />. <br />. <br />. <br />'. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />.' <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br />. <br /> <br />2.4 Equipment and Proiect Set-Up <br /> <br />The size of target area for 2003-2004 was approximately double that of the prior <br />season, expanded to include portions of the watershed that are south of Gunnison County. <br />The contract period for seeding operations was November 15, 2003 through April 15, <br />2004. The existing network of cloud nucleating generators (CNG's) was expanded from <br />the original 18 sites to a total of 27 sites by the end of the 2003-2004 winter season. <br />These new sites were located where they would be of value in seeding the southern <br />portion of the target area. Additionally, one of the original CNG sites (Black Mesa <br />Lodge) was replaced by a site further north (Crawford) along the western side of <br />Gunnison County. The existing Crawford site was renamed "Crawford South". Figure <br />2.1 is a map showing the seeding target areas and CNG sites. Table 2-2 lists the names, <br />latitude and longitude and elevation information for these sites. Figure 2.2 is a photo of a <br />ground-based CNG, similar to those used in the Gunnison County program. <br /> <br />The cloud seeding equipment consisted of a cloud seeding generator unit and a <br />propane gas supply. The seeding solution used in the 2003-2004 program contained 3% <br />silver iodide, rather than the 2% solution used during the previous season. This change <br />was made to increase the output of cloud seeding nuclei. The solution consists of <br />acetone, silver iodide, sodium iodide and para-dichlorobenzene. The seeding solution <br />contains three percent (by weight) silver iodide (AgI), the active seeding agent, <br />complexed with very small portions of sodium iodide and para-dichlorobenzene in <br />solution with acetone. Dr. William Finnegan of the Desert Research Institute published a <br />paper (Finnegan, 1999) suggesting that this formulation is superior to those that produce <br />pure silver iodide particles upon combustion. The modified particles act as ice-forming <br />nuclei much more quickly, and there are somewhat larger numbers of effective nuclei at <br />warmer temperatures (e.g. about -5 to -10C). <br /> <br />4 <br />