WMOD00544 - Laserfiche WebLink

Home Browse Search

I' L I f . I SlrEfJifJJG METlNQDS, > , 'I 'I '"'~.'" ' I \ ~",1' > ,,~ . j ~L } 8:" ~ ~ I PROJECT SKYW A TER HAS found that in the case of summer clouds, seeding by aircraft is effective. The silver iodide par- ticles generally are dispensed through a system of generators or regulated flares .a ttached to the aircraft. Hygroscopic seeding usually is accomplished with the use of aircraft since larger quantities of salt or urea are required. These are dis- pensed from a pressurized tank within the aircraft through a venting system into the updraft at the base of a cloud. In treating orographic clouds, the seeding agent is usually released from ground- based generators upwind from the target area. Since the orographic systems are large and relatively uniform, precise ,de- livery is not as essential as in small cu- mulus clouds. A generator has been de- signed and constructed to closely regwate the amount of silver iodide released from 20 to 140 grams per hour. Experiments with ground-based genera- tors in treating summer cumulus clouds have indicated that seeding agents can reach the base of clouds; however, this method apparently would also transport agents to clouds which do not need to be stimulated to produce additional moisture. In these cases, the introduction of seeding materials could reduce natural rainfall. Some generators and many weather moni- toring and sensing devices are located in remote areas and are subject to severe weather conditions. These have been linked to control centers by radio tele- metry systems. In addition to providing project meteorol- ogists with quick monitoring information, the network of sensing devices is being 15 A_,"'\" rr -'--, j" ... ~ I ~ 1. ."., ~- ERTS transmitter utilized by the Earth Resources Technol- ogy Satellite. ' Called ERTS-A, the "eye in the sky" is a first step in merging space and remote- sensing technologies into a system to in- ventory and manage Earth's resources. Skywater's project consists of monitoring weather conditions in the severe, high- altitude environment of the San Juan Mountains. Ground sensors broadcast data to the satellite on wind speed, wind direction, temperature of air and water, humidity, snow water content, and stream- flow. The experiment is designed to field test and resolve instrument-transmitter interface and operational problems. ~ il i I I The extensive instrument and communica- tions network and data assimilation abili- ties built into the Colorado River Basin Pilot Project provide a comprehensive base for determining the quality of ERTS-A data. These data will provide additional and more rapidly acquired in- formation for project operation.