RADIATIVELY FORCED DISPERSION OF THE MT-PINATUBO VOLCANIC CLOUD AND INDUCED TEMPERATURE PERTURBATIONS IN THE STRATOSPHERE DURING THE 1ST FEW MONTHS FOLLOWING THE ERUPTION

A combined 3-dimensional circulation model and aerosol microphysical/t ransport model is used to simulate the dispersion of the Mt. Pinatubo volcanic cloud in the stratosphere for the first few months following the eruption. Radiative heating of the cloud due to upwelling infrared radiation from the troposphere is shown to be an important factor aff ecting the transport. Without cloud heating, cloud material stays most ly north of the equator, whereas with cloud heating, the cloud is tran sported southward across the equator within the first two weeks follow ing the eruption. Generally the simulations agree with TOMS, AVHRR, an d SAGE satellite observations showing the latitude distribution of clo ud material to be between about 20-degrees-S and 30-degrees-N within t he first few months. Temperature perturbations in the stratosphere ind uced by the aerosol heating are generally 1-4 K, in the range of those observed.