Impacts of meteorology and emissions on summertime surface ozone increases over central eastern China between 2003 and 2015

Abstract

Abstract. Recent studies have shown that surface ozone (O3) concentrations over central eastern China (CEC) have increased significantly during the past decade. We quantified the effects of changes in meteorological conditions and O3 precursor emissions on surface O3 levels over CEC between July 2003 and July 2015 using the GEOS-Chem model. The simulated monthly mean maximum daily 8 h average O3 concentration (MDA8 O3) in July increased by approximately 13.6 %, from 65.5±7.9 ppbv (2003) to 74.4±8.7 ppbv (2015), comparable to the observed results. The change in meteorology led to an increase in MDA8 O3 of 5.8±3.9 ppbv over the central part of CEC, in contrast to a decrease of about -0.8±3.5 ppbv over the eastern part of the region. In comparison, the MDA8 O3 over the central and eastern parts of CEC increased by 3.5±1.4 and 5.6±1.8 ppbv due to the increased emissions. The increase in averaged O3 in the CEC region resulting from the emission increase (4.0±1.9 ppbv) was higher than that caused by meteorological changes (3.1±4.9 ppbv) relative to the 2003 standard simulation, while the regions with larger O3 increases showed a higher sensitivity to meteorological conditions than to emission changes. Sensitivity tests indicate that increased levels of anthropogenic non-methane volatile organic compounds (NMVOCs) dominate the O3 increase over the eastern part of CEC, and anthropogenic nitrogen oxides (NOx) mainly increase MDA8 O3 over the central and western parts and decrease O3 in a few urban areas in the eastern part. Budget analysis showed that net photochemical production and meteorological conditions (transport in particular) are two important factors that influence O3 levels over the CEC. The results of this study suggest a need to further assess the effectiveness of control strategies for O3 pollution in the context of regional meteorology and anthropogenic emission changes.

Ozone pollution over China and India: seasonality and sources

“…Because of the favorable weather conditions (increasing temperature and solar radiation and low precipitation) in spring and autumn (Fig. S7d), the seasonality of O 3 in the YRD exhibits a bridge shape, consistent with previous observations within this region (Tang et al, 2013). In addition, southerly winds might bring O 3 and its precursors from the YRD region in summer (Fig.…”

“…Besides, the summer monsoon can bring about cloudy and rainy weather conditions ( Fig. S7; removement of ozone precursors), weaker solar radiation, and lower temperature (Lu et al, 2018b), which are not conducive to the photochemical production of O 3 (Lu et al, 2018b;Tang et al, 2013). The onset of the summer monsoon is also associated with strong air convergence and uplift, which is not favorable for the accumulation of O 3 and its precursors (Lu et al, 2018b).…”

“…The contributions of individual economic sectors and source regions were reported based on sensitivity simulations and source apportionment techniques (Gao et al, 2016a;Li et al, , 2016Li et al, , 2012Lu et al, 2019;Wang et al, 2019). With respect to the enhanced concentrations of O 3 over the past years, Sun et al (2019) attributed them to elevated emissions of anthropogenic volatile organic compounds (VOCs), while Li et al (2019) argued that an inhibited aerosol sink for hydroperoxyl radicals induced by decreased PM 2.5 over 2013-2017 played a more important role in the North China Plain (NCP).…”

Substantial ozone enhancement over the North China Plain from increased biogenic emissions due to heat waves and land cover in summer 2017

“…Besides emissions, tropospheric ozone is also closely related to meteorological conditions, such as heat waves (Gao et al, 2013;Fiore et al, 2015;Otero et al, 2016), low wind speed and stagnant weather (Jacob and Winner, 2009;Sun et al, 2017;Zhang et al, 2018). Weather conditions concomitant with heat waves, including high temperature, low wind speed and little cloud coverage, may enhance ozone production (Jaffe and Zhang, 2017;Pu et al, 2017;Sun et al, 2019). At the same time, such meteorological conditions also promote emissions of BVOC and ozone formation (Zhang and Wang, 2016).…”

Significant ground-level ozone attributed to lightning-induced nitrogen oxides during summertime over the Mountain West States

“…Due to its adverse impact on human health 1 and ecosystem well being, 2 tropospheric ozone (O 3 ) has been at the center of air quality research during the past decades. [3][4][5] Ground-level O 3 is either produced through complex photochemical reactions involving nitrogen oxides (NO x ) and volatile organic compounds (VOCs), 6 with both anthropogenic and natural origins, or transported from other locations. 7 As air quality regulations are tightened and the contribution of anthropogenic sources to tropospheric O 3 levels is reduced in US and other economicallydeveloped regions, the natural sources becomes more increasingly important.…”