Over the last four years, a number of airborne field studies have been conducted in the United Arab Emirates (UAE). During the summer, the studies have concentrated on investigating convective clouds forming over the Al Hajir Mountains (also called the Oman Mountains) along and east of the border between the UAE and Oman in the eastern region of the Arabian Penisula. Most recently, the research flights have focussed on characterizing the development of precipitation near the -5 C level in order to examine hypotheses regarding the formation of drizzle-sized drops and their interaction with ice-phase processes.

Microphysical (aircraft) data and detailed radar data have been collected for several cases during a hygroscopic seeding experiment in both seeded and natural clouds. These will be examined and synthesized in order to characterize the conditions in which precipitation forms. This includes the formation of drizzle, the development of the ice process (nucleation, secondary ice particle production, riming, etc.), the resulting reflectivity structures, and the general progression of these processes. The larger objective is to examine these cases for evidence of hypothesized differences between seeded and unseeded clouds based on the microphysical seeding conceptual model outlined for the UAE studies.