Global transport of volcanic aerosol from El Chichon eruption studied with a three-dimensional circulation model

Abstract

We have used the three dimensional circulation model of the stratosphere developed at MIT-GIT, to study the global dispersion of the volcanic cloud from the El Chichón eruption. The time dependent model is run for four months up to the end of October 1982. lnitialization is provided through the measured latitude-altitude distribution of aerosol. Comparison of the results with experimental data made at days 105 and 120 from the beginning of the simulation sho:ws a reasonable agreement although the concentrations re:rnlting from the modelare shifted upward because the sedimentation velocity of the particles is ignored. Monthly means of the latitudelongitude section of the extinction ratio are also presented showing considerable inhomogeneity. A multiple scattering radiative code has been u sed to evaluate heating rates introduccd by a 75% sulfuric acid aerosol. In the first month a temperature increase up to 2° was,predicted.