Mesoscale Meteorology - Theories, Observations and Models

Mesometeorology was defined by Ligda in 1951 to include phe- nomena which are too large to be observed by in situ sensors at a single station but too small to be defined adequately by conven- tional station networks. The scientific, economic, and social im- portance of weather events on the scales of 10-1000 km is not a new discovery, but only recently have the weather services, research laboratories, and academic scientists of the world begun to concen- trate attention on these phenomena. An Advanced Study Institute was organized by the present editors to provide a focus and forum for review and dissemination of the current state of basic and ap- plied research across the broad and somewhat indefinite span (see Emanuel's first paper for one version) of this subject. We believe this objective was largely fulfilled, although not all relevant subjects were given attention equal to their perceived significance. The smaller and more intense mesoscale phenomena, especially con- vective clouds and storms, were excellently treated from a variety of viewpoints, while the important area of regional scale simula- tion and prediction received less emphasis. A fascinating discus- sion and mathematical treatment of a seemingly obscure cloud phe- nomena in Australia, the "morning glory", suggests that it may have much more generality and importance than is first apparent. New insights are obtained on the long-puzzling problem of the true nature and significance of turbulent entrainment into cumulus clouds.