Isotopic variation of rains and origin of the air masses in the Chilean Altiplano

This paper discusses isotopic composition of rains collected along the Cordillera del Medio and the Chilean Altiplano. This discussion is complemented with a meteorological study relating to the origin of the air masses that generate rain in northern Chile. The isotopic and meteorological evidences showed that the isotopic stratification observed in summer rains is not related to an altitude effect, but seems to be linked to the location of the convective centers that generate these rain storms. The different isotopic evolution observed between the summer and winter rains is related to the type of storms, being convective in nature during the summer and of frontal origin in the winter time. The meteorological study for the 1984 storm events showed that the source of the air masses is the Atlantic ocean via Amazonas basin. (author). 17 refs, 8 figs, 2 tabs