TIROS VORTICES AND LARGE-SCALE VERTICAL MOTION

Abstract

TIROS cloud photographs and fine-scale quasi-geostrophic calculations of vertical motion are used in an attempt to gain understanding of the evolution of vertices and other aspects of large-scale cloud masses and to explore the usefulness of the pictures in diagnosis of the vertical motions. Horizontal and vertical motions are found to be of roughly equal importance in the evolution of cloud patterns, except in the early phases of the storm, when the latter predominate. This circumstance complicates the diagnostic application of the pictures, but the evolution of cloud patterns is nicely accounted for. Cloud vortices occur in a variety of large-scale motion environments and seem to depend on fine-scale variations of motion and moisture structure which escape detection in conventional sounding networks. Quasi-geostrophic theory is found to yield at least qualitatively realistic vertical motions even in application to systems of smaller scale than can be justified a priori.