The future of airborne sulfur-containing particles in the absence of fossil fuel sulfur dioxide emissions.
Sulfuric acid (H2SO4), formed from oxidation of sulfur dioxide (SO2) emitted during fossil fuel combustion, is a major precursor of new airborne particles, which have well-documented detrimental effects on health, air quality, and climate. Another precursor is methanesulfonic acid (MSA), produced simultaneously with SO2 during the atmospheric oxidation of organosulfur compounds (OSCs), such as dimethyl sulfide. In the present work, a multidisciplinary approach is used to examine how contributions of H2SO4 and MSA to particle formation will change in a large coastal urban area as anthropogenic fossil fuel emissions of SO2 decline. The 3-dimensional University of California Irvine-California Institute of Technology airshed model is used to compare atmospheric concentrations of gas phase MSA, H2SO4, and SO2 under current emissions of fossil fuel-associated SO2 and a best-case futuristic scenario with zero fossil fuel sulfur emissions. Model additions include results from (i) quantum chemical calculations that clarify the previously uncertain gas phase mechanism of formation of MSA and (ii) a combination of published and experimental estimates of OSC emissions, such as those from marine, agricultural, and urban processes, which include pet waste and human breath. Results show that in the zero anthropogenic SO2 emissions case, particle formation potential from H2SO4 will drop by about two orders of magnitude compared with the current situation. However, particles will continue to be generated from the oxidation of natural and anthropogenic sources of OSCs, with contributions from MSA and H2SO4 of a similar order of magnitude. This could be particularly important in agricultural areas where there are significant sources of OSCs.
Department of Chemistry, University of California Irvine, Irvine, CA 92697;
Véronique
V
Perraud
Department of Mechanical & Aerospace Engineering, University of California Irvine, Irvine, CA 92697;
Jeremy R
JR
Horne
Department of Mechanical & Aerospace Engineering, University of California Irvine, Irvine, CA 92697;
Andrew S
AS
Martinez
Institute of Chemistry and the Fritz Haber Research Center, The Hebrew University of Jerusalem, Jerusalem 91904, Israel; Department of Chemistry, University of Helsinki, FIN-00014 Helsinki, Finland.
Jaroslaw
J
Kalinowski
Department of Chemistry, University of California Irvine, Irvine, CA 92697;
Simone
S
Meinardi
Department of Mechanical & Aerospace Engineering, University of California Irvine, Irvine, CA 92697;
Matthew L
ML
Dawson
Department of Chemistry, University of California Irvine, Irvine, CA 92697;
Lisa M
LM
Wingen
Department of Mechanical & Aerospace Engineering, University of California Irvine, Irvine, CA 92697;
Donald
D
Dabdub
Department of Chemistry, University of California Irvine, Irvine, CA 92697;
Donald R
DR
Blake
Department of Chemistry, University of California Irvine, Irvine, CA 92697; Institute of Chemistry and the Fritz Haber Research Center, The Hebrew University of Jerusalem, Jerusalem 91904, Israel; Department of Chemistry, University of Helsinki, FIN-00014 Helsinki, Finland.
R Benny
RB
Gerber
Department of Chemistry, University of California Irvine, Irvine, CA 92697; bjfinlay@uci.edu.
Barbara J
BJ
Finlayson-Pitts
D000393:Air Pollutants / Q000737:chemistry*; D064308:Ecological Parameter Monitoring / Q000379:methods / Q000639:trends; D004784:Environmental Monitoring / Q000379:methods; D005544:Forecasting; D005579:Fossil Fuels; D006801:Humans; D008698:Mesylates / Q000737:chemistry; D008962:Models, Theoretical; D010084:Oxidation-Reduction; D010316:Particle Size; D052638:Particulate Matter / Q000737:chemistry*; D013455:Sulfur / Q000737:chemistry*; D013458:Sulfur Dioxide / Q000737:chemistry*; D013464:Sulfuric Acids / Q000737:chemistry
D000393:Air Pollutants; D005579:Fossil Fuels; D008698:Mesylates; D052638:Particulate Matter; D013464:Sulfuric Acids; D013458:Sulfur Dioxide; C045880:methanesulfonic acid; D013455:Sulfur
atmosphere; fossil fuel; methanesulfonic acid; new particle formation; sulfuric acid