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<br />II. EXPERIMENTAL PLAN <br /> <br />The idea was to determine how many nucleating <br />sites would be required to cover the target area <br />under the conditions that usually prevail during a <br />major storm. Equipment techniques were available <br />for conducting diffusion tests, but required modi- <br />fication for field use. <br />The accurate measurement of precipitation-rate, <br />especially when the precipitation is mostly snow, <br />was largely an unknown area-and so we gave our- <br />selves as many options as possible. We planned to <br />test all the available precipitation sensor types, and <br />a heated tipping-bucket gage and an optical device <br />that we had been developing for research purposes. <br />Primary considerations included reliability, dy- <br />namic range, and frequency response-with accuracy <br />and long-term stability being secondary. The theory <br />was that if all instruments gave continuous and re- <br />latively accurate readings, the results would be <br />nearly as useful as if they were absolutely accurate, <br />since all results would have to be normalized during <br />analysis anyway. We finally chose the optical type <br />precipitation-rate sensor for the network. <br />We intended to gather data from all snow-rate <br />sensors automatically and at a central location. We <br />quickly disillusioned ourselves of this notion when <br />we determined that: <br /> <br />the program could not get started until I November <br />1964-already into the winter season; <br /> <br />we would have to use relay stations to obtain reliable <br />telemetering from the ridge stations and several of the <br />valley stations, <br /> <br />we could get across the ridge with a Sno-Cat almost at <br />will, <br /> <br />we would have to take snowcourse data at ridge and <br />valley stations at frequent intervals, and <br /> <br />there was no simple. inexpensive and reliable way of <br />getting both central digital collection and backup analog <br />records on-site. <br /> <br />Therefore, we decided to use on-site data collec- <br />tion and storage and a 5-day servicing cycle for <br />sensors. Snowcourse measurements were also set on <br />a 5-day cycle. The experience of Phase I has thor- <br />oughly vindicated this decision. The analog rec- <br />ords of snow-rate are a priceless store of information <br />for our evaluation and for research by others. <br />Record anomalies that we have been able to trace <br />to physical causes and correct for would have been <br />blindly digitized had we adopted either central or <br />on-site digitizing of data. Further, the cost of good <br />manual data reduction for an entire season's data <br /> <br />9 <br /> <br />has proved to be less than that of one piece of tele- <br />metering equipment. <br />For data processing we planned to employ a com- <br />puter program that we had already used on Pacific <br />Coast winter storm data. This has worked out well <br />and, except for minor printout and scaling modifi- <br />cations, has remained unchanged throughout Phase <br />I. The program gives us auto and cross-correlation <br />functions, power spectrum and cross-spectrum, <br />coherence and phase, storm total precipitation and <br />normalized value printout. Appendix C presents <br />the program listing. We originally planned to plot <br />these quantities directly for qualitative work, but <br />have since found that various normalizations greatly <br />facilitate analysis. <br />We planned to build the field operation around <br />a small group of technical personnel and hire locally <br />whatever additional labor was required; labor is <br />available in the Steamboat Springs area during the <br />winter months when ranching chores are at a mini- <br />mum. The overall program organization is shown <br />in figure 7. <br />The program schedule as proposed and as per- <br />formed is shown in figure 8. By using zinc sulphide <br />for diffusion work-'we originally planned to use <br />artificial nuclei themselves-we were able to cover a <br /> <br />BUREAU OF RECLAMATION <br /> DENVER <br />B. P. BELLPORT, CHIEF ENGR. <br />WALTER U. GARSTKA ,CHIEF, <br />OFFICE OF ATMOSPHERIC WATER RESOURCES <br />E.BOLLAY ASSOCIATES,INC <br /> BOULDER,COLORADO <br />E.BOLLAY, PROGRAM MANAGER <br />STEAM BOAT SPRINGS <br /> FACILITY <br />D.O. ZOPF, PROJECT ENGINEER <br />t ! <br />OPERATIONS DIFFUSION AND <br />ANALYSIS <br />R. A. BEGUN P. T. WILLIS <br /> <br />Figure 7.-Park Range Program Organization. <br />