Reduction of Global Sulfate Aerosol Concentration and Corresponding Radiative Effects From Recent Chinese SO2 Emission Reduction

Abstract

Anthropogenic emissions over China have recently declined due to environmental actions. This work estimates the sensitivity of sulfate aerosol ((Formula presented.)) concentration to the amount of (Formula presented.) emissions reduction over China from 2010 to 2020 using an Earth system model with two different aerosol representations. We find that a larger rate of (Formula presented.) emissions decline over 2010–2020 from an updated Chinese emission inventory leads to improvement in modeled (Formula presented.) and (Formula presented.) concentrations when evaluated with targeted airborne observations from the Asian summer monsoon region from the 2022 Asian summer monsoon Chemical and Climate Impact Project. Updated Chinese (Formula presented.) emissions reduce (Formula presented.) concentration by >20% at 200 hPa over the North Pacific, and by >7% at 100 hPa throughout the tropics. These (Formula presented.) reductions result in an increase to global net instantaneous radiative forcing of (Formula presented.) 0.10–0.15 W (Formula presented.) by 2020, with regional effects up to (Formula presented.) 6 times greater.