Global atmospheric sulfur budget under volcanically quiescent conditions: Aerosol‐chemistry‐climate model predictions and validation

Citations Over TimeTop 10% of 2014 papers

Abstract

Abstract The global atmospheric sulfur budget and its emission dependence have been investigated using the coupled aerosol‐chemistry‐climate model SOCOL‐AER. The aerosol module comprises gaseous and aqueous sulfur chemistry and comprehensive microphysics. The particle distribution is resolved by 40 size bins spanning radii from 0.39 nm to 3.2 μm, including size‐dependent particle composition. Aerosol radiative properties required by the climate model are calculated online from the aerosol module. The model successfully reproduces main features of stratospheric aerosols under nonvolcanic conditions, including aerosol extinctions compared to Stratospheric Aerosol and Gas Experiment II (SAGE II) and Halogen Occultation Experiment, and size distributions compared to in situ measurements. The calculated stratospheric aerosol burden is 109 Gg of sulfur, matching the SAGE II‐based estimate (112 Gg). In terms of fluxes through the tropopause, the stratospheric aerosol layer is due to about 43% primary tropospheric aerosol, 28% SO 2 , 23% carbonyl sulfide (OCS), 4% H 2 S, and 2% dimethyl sulfide (DMS). Turning off emissions of the short‐lived species SO 2 , H 2 S, and DMS shows that OCS alone still establishes about 56% of the original stratospheric aerosol burden. Further sensitivity simulations reveal that anticipated increases in anthropogenic SO 2 emissions in China and India have a larger influence on stratospheric aerosols than the same increase in Western Europe or the U.S., due to deep convection in the western Pacific region. However, even a doubling of Chinese and Indian emissions is predicted to increase the stratospheric background aerosol burden only by 9%. In contrast, small to moderate volcanic eruptions, such as that of Nabro in 2011, may easily double the stratospheric aerosol loading.

Related Papers

• → STRATOSPHERE/TROPOSPHERE EXCHANGE AND STRUCTURE | Tropopause(2014)9 cited
• → Calculating the global mass exchange between stratosphere and troposphere(1996)59 cited
• → Stratosphere‐troposphere ozone exchange observed with the Indian MST radar and a simultaneous balloon‐borne ozonesonde(1998)16 cited
• → Study of troposphere–stratosphere coupling through the Northern Annular Mode(2006)4 cited
• → Change in the attenuation coefficient of light at the boundary between the troposphere and stratosphere(2022)