O-18 DEUTERIUM AND CHLORIDE IN PRECIPITAT IONS FROM THE GAROUA REGION, NORTHERN-CAMEROON - METEOROLOGICAL IMPLICATIONS

Several rain samples collected in 1991 and 1992 rainy seasons at Garou a, Northern-Cameroon, have been analyzed for their O-18, H-2 and Cl co ntents. The isotopic composition of precipitation depends mainly on th e origin of air masses, and on the temperature at which the precipitat ion occurs in relation with the altitude of condensation of the atmosp heric vapour. The distribution of Cl- in rainwater provides useful inf ormation about the degree of emptying in the vapour reservoir and, con sequently, about the rate of migration of air masses induced by the co ntinental migration of the Inter-Tropical Convergence Zone.