The role of sulfur dioxide in stratospheric aerosol formation evaluated by using in situ measurements in the tropical lower stratosphere

摘要: Stratospheric aerosols (SAs) are a variable component of the Earth's albedo that may be intentionally enhanced in future to offset greenhouse gases (geoengineering). The role tropospheric-sourced sulfur dioxide (SO2) maintaining background SAs has been debated for decades without in-situ measurements SO2 at tropical tropopause inform this issue. Here we clarify by using new evaluate climate models and satellite retrievals. We then use observed mixing ratios estimate global flux across tropopause. These analyses show is about 5 times smaller than reported average observations have used recently test atmospheric models. This shifts view as dominant source near-negligible one, possibly revealing significant gap SA budget.