Abstract

The March-April 1982 eruptions of El Chichon produced the largest perturbation to the stratospheric aerosol since at least the 1963 eruption of Agung, and possibly the largest in the last 70 years. Its presence was soon detected by lidars in Hawaii and Japan as the upper portion of the cloud was driven by easterlies and began to immediately impact various remote sensors, producing artifacts in their retrievals. This stratospheric cloud was optically thick enough so that GOES could track it during an entire 3-week circuit of the Earth, At the same time material below about 20 km moved to the east-northeast. In addition, the clouds began spreading meridionally. The bulk of the material below about 20 km moved slowly toward the poles with portions arriving at the Arctic in late April. The material above 20 km contained most of the mass and was primarily confined to the northern Tropics (0° to 30°N) for about the first 6 months after the eruption. In late June and early July, portions of the upper cloud, which was peaked at about 26 km at that time, were detected at Langley (37°N).

© 1985 Optical Society of America