Fundamental Importance of Convective Downdrafts and Mass Recycling Within the Tropical Cloud Cluster and the Typhoon-Hurricane

Abstract

ABSTRACT Most meteorologists think of the organized tropical cloud cluster and typhoon-hurricane weather system as having a strong transverse (or ‘in-up-and-out’) circulation of low-level frictionally driven inflow, upward vertical motion in cloud areas, and outflow at upper tropospheric levels. Tropical weather systems also have another fundamentally important circulation within them which is an additional ‘down-and-up’ (or downdraft-and-updraft) circulation associated with evaporating downdraft motion and mass compensating condensation upward motion. This additional ‘down-and-up’ circulation has yet to be fully recognized and fully appreciated. This paper emphasizes the fundamental role of this additional ‘down-and-up’ circulation which must be added to the accepted ‘in-up-and-out’ basis transverse circulation to obtain a full understanding of the tropical weather system’s complete vertical circulation structure. Only by adding this additional extra ‘down-and-up’ is it possible to make simultaneous mass, energy, and moisture budgets for this class of weather system. This additional ‘down-and-up’ (or downdraft-and-updraft) circulation is indispensible in allowing tropical systems to extract large amounts of surface energy from the oceans.