Strong Dependence of U.S. Summertime Air Quality on the Decadal Variability of Atlantic Sea Surface Temperatures

• Published in: Geophysical Research Letters
• Main Authors: Shen, Lu, Mickley, Loretta J., Leibensperger, Eric M., Li, Mingwei
• Format: Article in Journal/Newspaper
• Language: English
• Published: John Wiley and Sons Inc. 2017
• Subjects: Atmospheric Composition and Structure; Pollution: Urban and Regional; Aerosols and Particles; Troposphere: Composition and Chemistry; Biogeosciences; Pollution: Urban; Regional and Global; Climate Dynamics; Global Change; Climate Variability; Oceans; Atmospheric Processes; Climate Change and Variability; Climatology; Oceanography: General; Marine Pollution; Climate and Interannual Variability; Natural Hazards; Megacities and Urban Environment; Oceanography: Physical; Decadal Ocean Variability; ozone; PM; AMO; multidecadal variability; North Atlantic
• Online Access: http://nrs.harvard.edu/urn-3:HUL.InstRepos:35982390; https://doi.org/10.1002/2017GL075905

Abstract We find that summertime air quality in the eastern U.S. displays strong dependence on North Atlantic sea surface temperatures, resulting from large‐scale ocean‐atmosphere interactions. Using observations, reanalysis data sets, and climate model simulations, we further identify a multidecadal variability in surface air quality driven by the Atlantic Multidecadal Oscillation (AMO). In one‐half cycle (~35 years) of the AMO from cold to warm phase, summertime maximum daily 8 h ozone concentrations increase by 1–4 ppbv and PM2.5 concentrations increase by 0.3–1.0 μg m−3 over much of the east. These air quality changes are related to warmer, drier, and more stagnant weather in the AMO warm phase, together with anomalous circulation patterns at the surface and aloft. If the AMO shifts to the cold phase in future years, it could partly offset the climate penalty on U.S. air quality brought by global warming, an effect which should be considered in long‐term air quality planning. Version of Record