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Impact of the 2008 Global Recession on air quality over the United States: Implications for surface ozone levels from changes in NO x emissions
Author(s) -
Tong Daniel,
Pan Li,
Chen Weiwei,
Lamsal Lok,
Lee Pius,
Tang Youhua,
Kim Hyuncheol,
Kondragunta Shobha,
Stajner Ivanka
Publication year - 2016
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2016gl069885
Subject(s) - recession , environmental science , air quality index , ozone , atmospheric sciences , air pollution , climatology , meteorology , geography , chemistry , geology , economics , organic chemistry , keynesian economics
Satellite and ground observations detected large variability in nitrogen oxides (NO x ) during the 2008 economic recession, but the impact of the recession on air quality has not been quantified. This study combines observed NO x trends and a regional chemical transport model to quantify the impact of the recession on surface ozone (O 3 ) levels over the continental United States. The impact is quantified by simulating O 3 concentrations under two emission scenarios: business‐as‐usual (BAU) and recession. In the BAU case, the emission projection from the Cross‐State Air Pollution Rule is used to estimate the “would‐be” NO x emission level in 2011. In the recession case, the actual NO 2 trends observed from Air Quality System ground monitors and the Ozone Monitoring Instrument on the Aura satellite are used to obtain “realistic” changes in NO x emissions. The model prediction with the recession effect agrees better with ground O 3 observations over time and space than the prediction with the BAU emission. The results show that the recession caused a 1–2 ppbv decrease in surface O 3 concentration over the eastern United States, a slight increase (0.5–1 ppbv) over the Rocky Mountain region, and mixed changes in the Pacific West. The gain in air quality benefits during the recession, however, could be quickly offset by the much slower emission reduction rate during the post‐recession period.