Global tracking of the SO2 clouds from the June, 1991 Mount Pinatubo eruptions

The explosive June 1991 eruptions of Mount Pinatubo produced the largest sulfur dioxide cloud detected by the Total Ozone Mapping Spectrometer (TOMS) during its 13 years of operation: approximately 20 million tons of SO2, predominantly from the cataclysmic June 15th eruption. The SO2 cloud observed by the TOMS encircled the earth in about 22 days (about 21 m/s); however, during the first three days the leading edge of the SO2 cloud moved with a speed that averaged about 35 m/s. Compared to the 1982 El Chichon eruptions, Pinatubo outgassed nearly three times the amount of SO2 during its explosive phases. The main cloud straddled the equator within the first two weeks of eruption, whereas the El Chichon cloud remained primarily in the Northern Hemisphere. The measurements indicate that Mount Pinatubo has produced a much larger and perhaps longer-lasting SO2 cloud; thus, climatic responses to the Pinatubo eruption can exceed those of El Chichon.