Cumulonimbus Vertical Velocity Events in GATE. Part II: Synthesis and Model Core Structure

Abstract

Abstract The properties of convective drafts and cores are presented in Part I. By our definition a convective updraft must have a positive vertical velocity for 0.5 km, and exceed 0.5 m s−1 for 1 s; a convective updraft core must exceed 1 m s−1 for 0.5 km. Downdrafts and downdraft cores are defined analogously. Here the properties of the drafts and cores are compared to results of previous work. In addition, the implications of the results in Part I are discussed. GATE cores and drafts are comparable in size and intensity to those measured in hurricanes but weaker than those measured in continental thunderstorms. The lesser intensity seems related to the nearly moist adiabatic GATE sounding. The mass flux by GATE cores is consistent with large-scale requirements. It is fairly evenly distributed over a range of core size and intensity. Updraft core vertical velocity and diameter are positively correlated, primarily the result of a few large strong events. The vast majority of GATE convective cores are suf...