Dynamics of Convective Upwelling of Large-Scale Weakly Heated Atmospheric Aggregates

Abstract

Equations for the center-of-mass speed of the parcel of heated air, the mass of the entrained cool air, and the resulting buoyancy of the entire air aggregate have been used to obtain exact and approximate relations for describing height and temporal dependences of the characteristic radius, the excess relative temperature, and convective upwelling of a weakly heated large-scale (hundreds of meters and greater) air aggregate. It is shown that the excess temperature relaxation in the air aggregate occurs quickly and the aggregate radius increases slowly and insignificantly. The variations in the center-of-mass speed of the aggregate are not monotonous. First, the speed increases from zero to the maximum value, and then it decreases to zero. Numerical simulations have been performed for the cases of interest to practical applications.