O3 Sensitivity and Contributions of Different NMHC Sources in O3 Formation at Urban and Suburban Sites in Shanghai

Lin, Haotian; Wang, Ming; Duan, Yusen; Fu, Qingyan; Ji, Wenhao; Cui, Huxiong; Jin, Dan; Lin, Yanfen; Hu, Kun

doi:10.3390/atmos11030295

Cited by 24 publications

(15 citation statements)

References 50 publications

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“…However, they displayed completely different behavior toward O 3 variation (Figure 6g,h): HCHO was apparently higher for clusters 1 and 4 associated with evident O 3 production, while NO 2 was difficult to distinguish among them. This implied that the photochemical generation of O 3 was basically dominated by VOCs rather than NO x in Shanghai, which has also been reported in previous studies [41,42].…”

Section: Clustering Of O3 Diurnal Patternssupporting

confidence: 85%

Clustering Analysis on Drivers of O3 Diurnal Pattern and Interactions with Nighttime NO3 and HONO

Wang

Zhang

et al. 2022

Atmosphere

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The long-path differential optical absorption spectroscopy (LP-DOAS) technique was deployed in Shanghai to continuously monitor ozone (O3), formaldehyde (HCHO), nitrogen dioxide (NO2), nitrous acid (HONO), and nitrate radical (NO3) mixing ratios from September 2019 to August 2020. Through a clustering method, four typical clusters of the O3 diurnal pattern were identified: high during both the daytime and nighttime (cluster 1), high during the nighttime but low during the daytime (cluster 2), low during both the daytime and nighttime (cluster 3), and low during the nighttime but high during the daytime (cluster 4). The drivers of O3 variation for the four clusters were investigated for the day- and nighttime. Ambient NO caused the O3 gap after midnight between clusters 1 and 2 and clusters 3 and 4. During the daytime, vigorous O3 generation (clusters 1 and 4) was found to accompany higher temperature, lower humidity, lower wind speed, and higher radiation. Moreover, O3 concentration correlated with HCHO for all clusters except for the low O3 cluster 3, while O3 correlated with HCHO/NOx, but anti-correlated with NOx for all clusters. The lower boundary layer height before midnight hindered O3 diffusion and accordingly determined the final O3 accumulation over the daily cycle for clusters 1 and 4. The interactions between the O3 diel profile and other atmospheric reactive components established that higher HONO before sunrise significantly promoted daytime O3 generation, while higher daytime O3 led to a higher nighttime NO3 level. This paper summarizes the interplays between day- and nighttime oxidants and oxidation products, particularly the cause and effect for daytime O3 generation from the perspective of nighttime atmospheric components.

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Section: Clustering Of O3 Diurnal Patternssupporting

confidence: 85%

Clustering Analysis on Drivers of O3 Diurnal Pattern and Interactions with Nighttime NO3 and HONO

Wang

Zhang

et al. 2022

Atmosphere

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“…For most of the newly-studied cites, urban areas were found in a VOC-limited regime, with two exceptions in Weinan and Nantong, both of which were in a mixed-limited regime [32,34]. However, transition from a VOClimited [35] to a mixed-limited O 3 formation regime [28] was indicated in some suburban areas of the YRD, mainly owing to decreases in NO x emissions in the recent years. As to altitude dependence, an analysis of airborne measurements in the NCP showed that O 3 formation became more sensitive to NO x emissions with increasing heights [36].…”

Section: O 3 Formation Regimementioning

confidence: 95%

“…Observation-based results from the past 5 years suggest that this situation has largely remained despite decrease in NO x emissions and increase in VOC emissions, e.g. in urban areas of Shanghai [28], Nanjing [29], and Wuhan [30]. The recent studies have expanded to less-developed cities NMVOCs are the total mass of non-methane hydrocarbons and oxygenated VOCs.…”

Section: O 3 Formation Regimementioning

confidence: 99%

Ground-level ozone pollution in China: a synthesis of recent findings on influencing factors and impacts

Wang

Xue

Zhu

et al. 2022

Environ. Res. Lett.

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Ozone (O3) in the troposphere is an air pollutant and a greenhouse gas. In mainland China, after the Air Pollution Prevention and Action Plan was implemented in 2013 – and despite substantial decreases in the concentrations of other air pollutants – ambient O3 concentrations paradoxically increased in many urban areas. The worsening urban O3 pollution has fuelled numerous studies in recent years, which have enriched knowledge about O3-related processes and their impacts. In this article, we synthesise the key findings of over 500 articles on O3 over mainland China that were published in the past six years in English-language journals. We focus on recent changes in O3 concentrations, their meteorological and chemical drivers, complex O3 responses to the drastic decrease in human activities during coronavirus disease 2019 lockdowns, several emerging chemical processes, impacts on crops and trees, and the latest government interventions.

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“…NO x can either promote O 3 production through photochemical reactions with atomic oxygen (O), O 2 , or mitigate O 3 formation by removing OH from the oxidation cycle. At the same time, ambient radical budget and weather conditions can also affect the O 3 generation regime (Li et al, 2019b;Liu and Wang, 2020a;Lin et al, 2020;Wang et al, 2020).…”

Section: Driving Factors Of Interannual Changes In O 3 From 2014 To 2020mentioning

confidence: 99%

Increasing but Variable Trend of Surface Ozone in the Yangtze River Delta Region of China

Tang

Zhang

Feng

et al. 2022

Front. Environ. Sci.

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Surface ozone (O3) increased by ∼20% in the Yangtze River Delta (YRD) region of China during 2014–2020, but the aggravating trend is highly variable on interannual time and city-level space scales. Here, we employed multiple air quality observations and numerical simulation to describe the increasing but variable trend of O3 and to reveal the main driving factors behind it. In 2014–2017, the governmental air pollution control action plan was mostly against PM2.5 (mainly to control the emissions of SO2, NOx, and primary PM2.5) and effectively reduced the PM2.5 concentration by 18%–45%. However, O3 pollution worsened in the same period with an increasing rate of 4.9 μg m−3 yr−1, especially in the Anhui province, where the growth rate even reached 14.7 μg m−3 yr−1. After 2018, owing to the coordinated prevention and control of both PM2.5 and O3, volatile organic compound (VOC) emissions in the YRD region has also been controlled with a great concern, and the O3 aggravating trend in the same period has been obviously alleviated (1.1 μg m−3 yr−1). We further combined the precursor concentration and the corresponding O3 formation regime to explain the observed trend of O3 in 2014–2020. The leading O3 formation regime in 2014–2017 is diagnosed as VOC-limited (21%) or mix-limited (58%), with the help of a simulated indicator HCHO/NOy. Under such condition, the decreasing NO2 (2.8% yr−1) and increasing VOCs (3.6% yr−1) in 2014–2017 led to a rapid increment of O3. With the continuous reduction in NOx emission and further in ambient NOx/VOCs, the O3 production regime along the Yangtze River has been shifting from VOC-limited to mix-limited, and after 2018, the mix-limited regime has become the dominant O3 formation regime for 55% of the YRD cities. Consequently, the decreases of both NOx (3.3% yr−1) and VOCs (7.7% yr−1) in 2018–2020 obviously slowed down the aggravating trend of O3. Our study argues that with the implementation of coordinated regional reduction of NOx and VOCs, an effective O3 control is emerging in the YRD region.

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O3 Sensitivity and Contributions of Different NMHC Sources in O3 Formation at Urban and Suburban Sites in Shanghai

Cited by 24 publications

References 50 publications

Clustering Analysis on Drivers of O3 Diurnal Pattern and Interactions with Nighttime NO3 and HONO

Clustering Analysis on Drivers of O3 Diurnal Pattern and Interactions with Nighttime NO3 and HONO

Ground-level ozone pollution in China: a synthesis of recent findings on influencing factors and impacts

Increasing but Variable Trend of Surface Ozone in the Yangtze River Delta Region of China

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