Atmospheric impact of the volcanic eruptions of El Chichon over Mexico.

Abstract

In the present study we report the tropospheric effects observed on the Mexican territory of El Chichon volcano eruptions. We have used in the study, the air surface temperature records of 5 observatories as well as solar radiation and atmospheric turbidity measurements made in Mexico City. The results show that from May-June 1982 to March-April 1983, a temperature cooling trend was observed in all the Observatories, followed by an abrupt warming in the summer of 1983 concomitant to an important extinction of direct solar radiation and the corresponding elevation of atmospheric turbidity. The observed regional cooling is in agreement with the results of radiative transfer models on atmospheric effects of volcanic eruptions. The joint analysis of our results together with those reported from NASA aircraft observations and those of stratospheric balloons performed at the same time period, points out to the conclusion that this regional tropospheric warming associated to an important solar radiation extinction, may be due to the massive descent into the troposphere of the stratospheric volcanic aerosols. -Authors