Sulfuric acid decomposition chemistry above Junge layer in Earth's atmosphere concerning ozone depletion and healing

Abstract

Sulfuric acid (H₂SO₄) is the seed molecule for formation of stratospheric sulfate aerosol layer that assists ozone depletion by activation of halogen species. The impact of increased stratospheric sulfate aerosols due to large volcanic eruptions and possible side effect claimed in the geoengineering scheme of global climate using man-made injected stratospheric sulfate aerosols is ozone depletion. Given that both volcanic eruptions and geoengineering scheme are ultimately connected with increased upper stratospheric concentrations of H₂SO₄, here we show by theoretical approach that the pressure-independent H₂SO₄ + O(¹D) insertion/addition reactions via barrierless formation of peroxysulfuric acid (H₂SO₅) or HSO₄ + OH radicals or sulfur trioxide (SO₃) + hydrogen peroxide (H₂O₂) molecules are the potential routes towards H₂SO₄ loss above the stratospheric sulfate aerosol layer, and for the regeneration or transportation of consumed lower-middle stratospheric OH radical in the upper stratosphere at the cost of O(¹D)/ozone.

The decomposition of sulfuric acid molecule in the stratosphere contributes to the depletion of ozone layer and therefore requires improved understanding. Here the authors present a theoretical approach to understand the sulfuric acid loss mechanism of potential atmospheric significance.