(C) A High Altitude Wind Observation From Nuclear Explosion ''Teak” J. W. Reed Sandia Laboratory An article by Church’ 1 speculates on circulation speeds at 660 km altitude caused by diurnal density fluctuations reported by Priester, et al. 2 from satellite orbital data. There is some observational evidence, not previously publicized, for these extreme speeds. At the high-altitude nuclear burst (Teak) experiment above Johnston Island, 1 August 1958, a cloud observation was made which seems to imply fantastic horizontal cloud motion and altitude. graphic or optical measurements of Teak phenomena were made. the cloud motion interpretation. Few systematic photo- Electronic measurements did not support Now, however, with several bits of rough data assembled, a reasonable assertion can be made. From the U.S.S. Boxer, about 90 km northeast of Johnston Island, the familiar toroidal atomic cloud from Teak appeared to rise rapidly from the burst vicinity, separating from the feathery glowing region which was photographed for several minutes from Hawaii by Steiger and Matsushita. 8 After a few minutes, only fragments of this high debris cloud could be discerned. At H + 20 minutes, during observation of the auroral phenomena produced by the shot, a wisp of white cirrus was noted about 20 degrees above the northern horizon, and just to the right of the auroral belt which extended out of sight into the north. grew and soon came to appear as remains of the Teak cloud. the toroidal shape. again. This first wisp gradually Toa vivid imagination it still seemed to retain Thus, the debris cloud must have risen and drifted north into the sunlight to become visible Rough calculations showed that sunlighting on this bearing would have occurred 1500 miles away from surface zero at hundreds of miles altitude in 20 minutes, The subject was dropped. With reports of radical diurnal density and allied circulation patterns at high altitudes, it is reasonable to attempt more accurate calculations. There are still no direct measurements, but a combination of subjec- tive arguments shows that a large error in the conclusion is unlikely. A Teak configuration was sketched by H. E. Bell of Sandia Laboratory as he viewed it from French Frigate Shoals. Pertinent portions of his view at H+ 2 minutes are shown in Figure 1. An approximate scale for his sketch was obtained from the red sphere diameter at H + 2 minutes as photographed by Hawaii-based cameras, His line of sight on the auroral base is established by construction in Figure 2, since the belt was directed toward magnetic north, 14 degrees east of true north, the inclination of the belt. Local magnetic dip, 25 degrees’, establishes From the Boxer, azimuth of the belt segment, 20 degrees above horizontal, is triangulated in Figure 3 to give cirrus cloud bearing 2 degrees east of north. If any of the observations are varied by as much as 10 degrees, the resultant cloud bearing is changed a comparably small amount. 47