Title: Source apportionments of aerosols and their direct radiative forcing and long-term trends over continental United States

Abstract

Due to US air pollution regulations, aerosol and precursor emissions have decreased during recent decades, while changes in emissions in other regions of the world also influence US aerosol trends through long-range transport. We examine here the relative roles of these domestic and foreign emission changes on aerosol concentrations and direct radiative forcing (DRF) at the top of the atmosphere over the continental US. Long-term (1980-2014) trends and aerosol source apportionment are quantified in this study using a global aerosol-climate model equipped with an explicit aerosol source tagging technique. Due to US emission control policies, the annual mean near-surface concentration of particles, consisting of sulfate, black carbon, and primary organic aerosol, decreases by about –1.1 (±0.1) / –1.4 (±0.1) μg m^-3 in western US and –3.3 (±0.2) / –2.9 (±0.2) μg m^-3 in eastern US during 2010–2014, as compared to those in 1980–1984. Meanwhile, decreases in US emissions lead to a warming of +0.48 (±0.03) / –0.46 (±0.03) W m^-2 in western US and +1.41 (±0.07) /+1.32 (±0.09) W m^-2 in eastern US through changes in aerosol DRF. Increases in emissions from East Asia generally have a modest impact on US air quality, but mitigated the warming effect induced bymore » reductions in US emissions by 25% in western US and 7% in eastern US. Thus, as US domestic aerosol and precursor emissions continue to decrease, foreign emissions may become increasingly important to radiative forcing over the US.« less

Authors:

Yang, Yang  ^[1];

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Wang, Hailong  ^[1];

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Smith, Steven J.  ^[2];

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Zhang, Rudong ^[1]; Lou, Sijia  ^[1];

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Yu, Hongbin ^[3]; Li, Can ^[4]; Rasch, Philip J.  ^[1]

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• Search DOE PAGES for ORCID "0000-0002-5125-2174"
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+ Show Author Affiliations

1. Pacific Northwest National Lab. (PNNL), Richland, WA (United States). Atmospheric Science and Global Change Div. (ASGC)
2. Joint Global Change Research Inst. (JGCRI), College Park, MD (United States)
3. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States)
4. NASA Goddard Space Flight Center (GSFC), Greenbelt, MD (United States); Univ. of Maryland, College Park, MD (United States). Earth System Science Interdisciplinary Center

Publication Date:

2018-05-23

Research Org.:

Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States). National Energy Research Scientific Computing Center (NERSC)

Sponsoring Org.:

Office of Science (SC), Biological and Environmental Research (BER). Earth and Environmental Systems Science Division; National Aeronautics and Space Administration (NASA)

OSTI Identifier:

1440340

Alternate Identifier(s):

OSTI ID: 1441048

Report Number(s):

PNNL-SA-129873
Journal ID: ISSN 2328-4277

Grant/Contract Number:  

AC0576RL01830; NNH15AZ64I

Resource Type:

Accepted Manuscript

Journal Name:

Earth's Future

Additional Journal Information:

Journal Volume: 6; Journal Issue: 6; Journal ID: ISSN 2328-4277

Publisher:

American Geophysical Union (AGU)

Country of Publication:

United States

Language:

English

Subject:

54 ENVIRONMENTAL SCIENCES; Aerosol; Source Apportionment; Radiative Forcing; Long‐Term Trends; Air Quality; Emission