On the potential importance of sulfur-induced activation of soot particles in nascent jet aircraft exhaust plumes

The chemical conversion of emitted SO₂ and SO₃ to gaseous H₂SO₄ in nascent aircraft exhaust plumes and subsequent adsorption of the fully oxidized sulfur species on the surfaces of emitted combustion aerosols (soot) is investigated. Results are presented for the mass fractions of SO₃ and H₂SO₄ acquired per soot particle early in the plume, suggesting that sulfur-induced activation is an efficient pathway to increase the ability of exhaust soot emitted at altitude to host heterogeneous chemical reactions and to trigger the formation of cirrus clouds.