The chemical and radiative effects of the Mount Pinatubo eruption
- Lawrence Livermore National Lab., CA (United States); and others
The eruption of Mount Pinatubo introduced large amounts of sulfur-containing particles into the stratosphere. Stratospheric ozone measured by ozonesondes and satellites is significantly lower following the June 1991 eruption and throughout 1992 and 1993. To clarify the mechanisms leading to effects on stratospheric ozone, time-dependent stratospheric aerosol and gas experiment II (SAGE II) and cryogenic limb array elaton spectrometer aerosol optical extinction data and SAGE II surface area density are used as parameters in a two-dimensional (2-D) zonally averaged chemical radiative transport model. The model was integrated with time from before the eruption through December 1993. The modeled impact on global ozone results from increased rates of heterogeneous reactions on sulfate aerosols and from the increased radiative heating and scattering caused by these aerosols. The model`s dynamic response to changes in forcing (from changes in radiatively active trace gas concentrations and from aerosol heating) is treated in one of three ways: (1) the stratospheric temperature is perturbed, with fixed seasonal circulation, (2) the circulation is perturbed, with fixed seasonal temperature, or (3) both circulation and temperature are unperturbed, when investigating only the impact of Mount Pinatubo increased aerosol surface area density and aerosol scattering of actinic solar radiation. When the effect of heterogeneous chemical processing on sulfate aerosols is combined with aerosol heating, modifying either circulation or temperature, dramatically different ozone fingerprints with time and latitude are predicted. Model-derived changes in the equatorial region in column zone best represented the observed data when perturbed circulation was combined with heterogeneous chemical effects. However, at high latitudes, the increased ozone production from the strengthening of the mean circulation tends to cancel the heterogeneous reduction of ozone. 77 refs., 16 figs., 7 tabs.
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 114766
- Journal Information:
- Journal of Geophysical Research, Vol. 99, Issue D12; Other Information: PBD: 20 Dec 1994
- Country of Publication:
- United States
- Language:
- English
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