Laserfiche WebLink
<br />0025()~J <br /> <br />Three case studies from Montana and Texas have been analyzed and <br />compared with actual observations. Results indicate a "time window" <br />for the icing process in natural (unseeded) cases. This window is <br />related to the concentration of natural ice nuclei and windflow <br />pattern. Ice precipitation processes were shown to be dominant in <br />Mont ana. <br /> <br />CONTRACTOR: Colorado State University, Fort Collins, Colorado <br />CONTRACT NO. 6-07-0R-20020 <br />PRINCIPAL INVESTIGATORS: Oavi d Reynolds and Thomas Vonder H aar <br />PERIOD: July 20, 1975 - Continuing <br />FUNDING: FY76 - $ 38,000 <br />T.Q. $ 25,000 <br />FY77 - $ 70,354 <br />FY78 - $116,468 <br /> <br />This is a continuation of the digital satellite imagery analysis <br />initiated under Contract No. 14-06-0-7630 to develop and demonstrate <br />case study and cloud population climatology applications for Project <br />Skywater. Studies have been undertaken in connection with HIPLEX, <br />the SCPP, and the Colorado River Basin Program. <br /> <br />During the 1976 HIPLEX field season, activities concentrated on <br />real-time satellite support, data collection, postanalysis and <br />classification of daily activity relating to synoptic and mesoscale <br />triggering mechanisms, comparison of satellite and radar meas- <br />urements, and modification of the satellite and radar data processing <br />system. Data from vertical temperature soundings were also studied <br />as an aid in analyzing.the mesoscale variability of temperature and <br />moisture to determine controls of convective cloud developments. <br /> <br />In 1977, analyses of 1976 case studies demonstrated that digital <br />satellite data can be compared with radar and rain gage data to <br />obtain point rainfall measurements. The results may contribute to <br />HIPLEX extra-area effects analyses. It was discovered that the <br />satellite can observe clouds up to 20 minutes before they appear on <br />radar, a valuable asset in field experiments. Usin9 the 1976 data <br />set, preliminary analyses of the Miles City satellite climatology <br />began. The northeast quadrant of the 150-km experimental area seems <br />to experience the greatest number of clouds. <br /> <br />Late in 1977, the contract was amended to include work in SCPP and <br />the Colorado River Basin. Detailed intensive case studies of 1977-78 <br />SCPP field season data showed that postfrontal clouds had top temper- <br />atures in the seeding window. Mesoscale convective bands were <br />clearly visible in imagery and appeared to be associated with the <br />heaviest precipitation. These studies indicate the importance of <br />quantitative satellite observation in winter orographic studies. In <br /> <br />I II -22 <br />