Rain Duration in Hawaiian Trade-Wind Rainbands—Aircraft Observation

Abstract

Data obtained from aircraft observations conducted around the island of Hawaii during the 1985 Joint Hawaii Warm Rain Project was analyzed pertaining to the microphysical, thermodynamic and dynamic characteristics of rainbands. Analysis focused upon rain duration and rain accumulation. The most outstanding feature of long-lasting trade-wind rainbands is that unlike other storm systems, dry air does not intrude into the main cloud system at low levels. A certain rainwater accumulation process seems to occur that produces heavy rainfall. This is accompanied by the production of a large amount of drizzle in the middle levels of the cloud. An increase in the drop growth rate within cloud cells above zones of low level convergence, as well as drop recirculation, influence efficient production of a ?drizzle pool?.