The Effect of Ozone Photochemistry on Atmospheric and Surface Temperature Changes Due to Increased CO₂, N₂O, CH₄ and Volcanic Aerosols in the Atmosphere

Abstract

Increased atmospheric CO₂, N₂O, CH₄ and volcanic aerosols can affect indirectly the stratospheric ozone by altering the temperature structure and through photochemical coupling. The radiative effects which result from the local ozone perturbations would in turn modify the initial temperature changes due to increased CO₂, N₂O, CH₄ and volcanic aerosols. In this paper a coupled 1-D radiative-convective and photochemical diffusion model is used to study the influence of ozone photochemistry on changes in the vertical temperature structure and surface climate resulting from the doubling of atmospheric CO2, N₂O, CH₄ and increased stratospheric aerosols due to El Chichon volcanic eruption. It is found when CO₂ alone is doubled, the total ozone column has increased by nearly 6% and the resulting growth in the solar heating has contributed to the smaller temperature decrease in the stratosphere (up to 4⁰K temperature recovery near the stratopause level). But when the concentrations of C0_2, N₂O and CH₄ are doubled, the total ozone column amount has increased only by 2.5%, resulting in a reduced temperature recovery in the stratosphere. Also discussed is the interaction of ozone photochemistry with the stratospheric aerosol cloud produced from the El Chichon eruption.