Laserfiche WebLink
<br />. . <br /> <br />8.18. Super, A. B., E. Faatz, A. J. Hilton, JI': C. Ogden and R. D. Hansen, 1995: A status report on <br />liquid propane dispenser testing in Utah with emphasis on afully-automated seeding system. J. <br />Weather Modification, 27, 84-93. <br /> <br />. . <br /> <br />ABSTRACT <br /> <br />Liquid propane dispensers were tested on the Wasatch Plateau of central Utah during the winters of 1992- <br />93 and 1993-94. Remote operation of the radio-controlled dispensers proved to be highly reliable, in large <br />-.part because of the mechanical simplicity of the devices. A prototype fully-automated liquid propane <br />seeding system was tested during early 1994 on the west (windward) slopes of the Plateau. An icing rate <br />device was used to detect supercooled liquid water at the center station of three exposed propane <br />dispenser stations. Wind speed and direction and air temperature were also monitored at the center <br />station. When certain predetermined weather criteria were met, the three propane dispensers were <br />automatically turned on. Propane continued to be dispersed until one of more of the weather criteria were <br />out-of-bounds for 2 h. <br /> <br />Post season analysis of recorded data showed that the fully-automated seeding system operated as <br />designed for the most part. Some minor problems were encountered, but can easily be corrected. <br />Recommendations are made for simplifying the automated decision process. <br /> <br />A means of detecting supercooled liquid water in the absence of commercial electrical power was also <br />tested during early 1994. It proved to be practical and reliable. Accordingly, the technology exists to <br />operate fully-automated networks of liquid propane dispensers in remote mountain locations. Costs of <br />such networks would. not be excessive, and reliability can be expected to be high. However, further <br />physical experimentation is recommended to document the effectiveness of liquid propane seeding for <br />snowfall enhancement because such evidence is quite limited. <br /> <br />SUMMARY AND RECOMMENDATIONS <br /> <br />A propane dispenser was tested during the 1992-1993 winter, well up the west slope of the Wasatch <br />Plateau east of Fairview. Utah. The dispenser was based on the design of Reynolds (1989, 1991), with <br />some modifications. The dispenser was turned on and offby a data logger/controller upon receipt of <br />appropriate radio signals from a valley base stations. Human intervention and a computer were used to <br />initiate the radio signals. Various data were logged at the site and periodically downloaded to the base <br />station. . <br /> <br />A technician was often at the dispenser site, monitoring its operations, while a second technician turned <br />the system on and off. These visual observations helped to confirm the very reliable operation of the <br />propane dispenser. <br /> <br />.( <br /> <br />Further testing was done during early 1994, in two different modes. In the first mode, two dispensers <br />were used during physical seeding experiments with system start-up and shutdown done as in th~ prior <br />winter (human intervention, radio telemetry and computers). The physical seeding experiments have yet <br />to be analyzed and reported, but dispenser operation was again very reliable. <br /> <br />. . <br /> <br />The second testing mode involved a prototype seeding system which was automatically turned on and off <br />according to weather observations: The weather (SL W, wind and temperature) was monitored at a central <br /> <br />66 <br />