Laserfiche WebLink
<br />winter could be reached only by. helicopter during fine weather <br />breaks called for the use of remote-controlled generators. <br />The resolution of the problems which arose from these <br />aspects of the project and the need to acquire and field test <br />equipment delayed the commencement of operational seeding until <br />the second winter. <br />During that season9 as described in Chapter 59 a system <br />test was carried out9 and randomized seeding was undertaken using <br />randomized pairs of days. Seeding began and ended at 11 a.m. in <br />order to facilitate measurements of precipitation and the observa- <br />tion of physical effects of seeding. During this winter season9 <br />following a search for adequate statistical consu1tation9 contact <br />was made with the Berkeley Statistical Laboratory at the <br />University of California~ Berke1eY9 and after lengthy discussions9 <br />a much-improved statistical design was adopted which took account <br />of the characteristic temporal distribution of precipitation in <br />the Sierra Nevada9 and of the nature of the precipitation measure- <br />ments which were available. This design9 which was applied to the <br />remaining three seasons (1972-739 1973-749 and 1974-75)9 is <br />described in Chapter 7. Thus9 the first two seasons were occupied <br />with equipment acquisition9 testing and modification and the devel- <br />opment of an appropriate statistical design for the project which <br />was carried out during the last three seasons. <br />During these three seasons9 the Berkeley Statistical <br />Laboratory provided extensive statistical consultation; they <br />carried out the statistical analysis of the three-year project <br />data9 as described in Chapter 139 with the preliminary results <br />described in Chapter 14. These results indicate that the <br />apparent effect of seeding was to increase precipitation. However9 <br />the preliminary analysis so far conducted does not justify a <br />hiah level of confidence in this conclusion. Further analytical <br />work may improve this situation9 or permit a clearer description <br />of the weather situations in which seeding could be most -effec- <br />tively used to increase precipitation. <br /> <br />1-3 <br />