COPT 81: A Field Experiment Designed for the Study of Dynamics and Electrical Activity of Deep Convection in Continental Tropical Regions

Abstract

During May and June 1981 several French research organizations, the University of Abidjan (Ivory coast) and the Agency for security of Aeronautical Navigation (ASECNA), participated in the observational field program called ?Convection Profonde Tropicale 1981? (COPT 81). COPT 81 was directed toward developing a better understanding of the dynamical and electrical features of precipitating convection in continental tropical regions. The observational network was designed to study the development and evolution of diurnal convection and squall lines over the northern part of the Ivory Coast, which is an example of a tropical savanna region at the southern edge of the Sahel. It consisted of two Doppler radars, a central meteorological station equipped for the reception of satellite data, rawin sounding and interrogation of remote targets, an acoustic sounder, a central electrical and electro-magnetical station, and a set of remote ground meteorological and electrical stations. Some experimental results are presented to characterize the main features of a tropical continental squall line. The evolution of the boundary layer during its passage, its precipitation pattern and associated dynamical field, its surface trace and the modification it produces on the thermodynamical state of the atmosphere, as well as some of its associated electrical features, are given.