Comparison of high-altitude dispersion predictions to Crystal Mist test data

Two computer models that have been developed to predict high-altitude turbulence and diffusivity have been installed in a code called MESO, which uses tracer techniques to model transport and dispersion. One model is for background turbulence produced by gravity waves and the other is for clear-air turbulence layers. Based on profiles of temperature and wind speed, the models are relatively straight forward to use and are numerically fast. Comparisons are shown between model predictions and dispersion data from a field test program called Crystal Mist in which over 220 kg of glass beads were dispensed at altitudes of around 6 to 7 km above sea level. Three bead sizes were released with mass median diameters of 40, 70 and 200 microns. The resulting clouds, which were released at the Nevada Test Site, were tracked from the ground by a lidar operated by NOAA for up to 80 minutes after their generation. To supply the needed meteorology, a series of five to seven rawinsondes were released during each test period.