TEMPERATURES AND TURBULENCE AT TROPOPAUSE LEVELS OVER HURRICANE BEULAH (1967)

Abstract

Horizontal and vertical temperature variations along with true gust velocity measurements of atmospheric turbulence were obtained above hurricane Beulah (1967) by an instrumented U?2. The U?2 flight was part of the U.S. Air Force High Altitude Clear Air Turbulence program. Pertinent findings include: (1) location of the tropopause just above the cloud tops at 54,000 ft (100 mb) with a temperature of ?86°C, 12°C lower than the mean; (2) a vertical temperature rise of 11°C in a few hundred feet just above the tropopause; (3) horizontal temperature changes up to 7°C and smooth flight conditions in the stable layer above the cloud tops; and (4) small temperature fluctuations and generally turbulent conditions at cloud top level. Aircraft measured winds, although questionable as to their exact directions and speeds, indicated that the flow was weak and anticyclonic near Beulah's top, becoming increasingly anticyclonic above.