Increase in Surface Ozone over Beijing-Tianjin-Hebei and the Surrounding Areas of China Inferred from Satellite Retrievals, 2005-2018

Lia, Yu; Cheng, Miaomiao; Guo, Zheng; Zhang, Xiuying; Cui, Ximin; Chen, Shenghai

doi:10.4209/aaqr.2019.11.0603

Cited by 18 publications

(8 citation statements)

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“…In addition, reduced retrieval sensitivity in winter due to larger solar zenith angle is also one of the reasons for this result. Only a significantly reduced NO x titration effect was expected in winter [20,83] in the aftermath of the rapid decrease in NO 2 , yielding a more pronounced increase in winter O 3 during 2013-2018, as shown in Figure S7. These phenomena, the summer HCHO increase, especially in 2005-2012, and the winter NO 2 decrease in 2013-2018, both led to an enhancement of the annual average O 3 in regions 1-2, reflecting the NO x -saturated O 3 sensitivity.…”

Section: Discussionmentioning

confidence: 91%

“…Therefore, VOC reduction along with NO x reductions are needed in megacities in the immediate short term to reduce O 3 levels. To date, there have been a few reports on this phenomenon for the warm season (e.g., from Beijing-Hebei and Chengdo, as well as from rural areas near the Yangtze River delta for a specific warm period) [77][78][79][80][81][82][83]. Here, warm and cold season features have also been completely characterized to explain the annual mean O 3 enhancement over the Asia-Pacific region.…”

Section: Discussionmentioning

confidence: 92%

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Ozone Continues to Increase in East Asia Despite Decreasing NO2: Causes and Abatements

et al. 2021

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Space-borne ozone (O3) measurements have indicated consistent positive trends across the entire Asia–Pacific region despite the considerable reduction of NOx since 2000s. The rate of increase in O3 derived from lower free tropospheric column measurements was observed to be 0.21 ± 0.05 DU/decade during 2005–2018. Our space-borne-based diagnosis of the nonlinear photochemical formation regimes, NOx-limited and NOx-saturated, show that O3 chemistry is undergoing a transitional process to the NOx-limited regime throughout most of the Asian region. Nevertheless, NOx-saturated conditions persist at present in and over eight major megacities. These NOx-saturated conditions in megacities contribute to the increased O3 due to NOx reduction, which could also affect the enhanced O3 concentrations throughout the Asia–Pacific region via long-range transport. This indicates that VOC limits along with NOx reductions are needed in megacities in the short term to reduce O3 levels. Moreover, NOx saturation in major megacities will continue until 2025, according to the forecast emission scenarios from the Intergovernmental Panel on Climate Change (IPCC). These scenarios gradually shift nearly all cities to the NOx-limited regime by 2050 with the exception of few cities under IPCC RCP8.5. Thus, continued reductions in NOx will be a key factor in reducing O3 in the long term.

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Section: Discussionmentioning

confidence: 91%

Section: Discussionmentioning

confidence: 92%

Ozone Continues to Increase in East Asia Despite Decreasing NO2: Causes and Abatements

et al. 2021

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“…The alternative indicators of the HCHO/NO 2 column concentration ratio, derived from satellite data, , and the ozone/NO y concentration ratio (NO y refers to the sum of NO x and its oxidation products) are more robust . Among several commonly used satellite data, the OMI data is more applicable for revealing the spatial and temporal gradient variations of ozone-forming sensitivity (OFS) because of its finer resolution. ,,, …”

Section: Introductionmentioning

confidence: 99%

“…3 Among several commonly used satellite data, the OMI data is more applicable for revealing the spatial and temporal gradient variations of ozone-forming sensitivity (OFS) because of its finer resolution. 9,14,20,21 Influenced by ozone precursor emissions, meteorology, geography, and other relative factors, OFS is usually spatially and temporally heterogeneous. 22−24 In addition to local precursor emissions, meteorological conditions are critical in the formation and transmission of ozone.…”

Section: Introductionmentioning

confidence: 99%

Long-Term (2011–2019) Trends of O₃, NO₂, and HCHO and Sensitivity Analysis of O₃ Chemistry over the GBM (Ganges–Brahmaputra–Meghna) Delta: Spatial and Temporal Variabilities

Pavel

Zaman

Jeba

et al. 2021

ACS Earth Space Chem.

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Decadic (2011Decadic ( −2019 column NO 2 , HCHO, and surface O 3 of nine different locations were studied over the GBM (Ganges−Brahmaputra−Meghna) delta. Column-based HCHO/ NO 2 ratios were employed to characterize ozone formation sensitivity. Level-3 gridded retrievals from Ozone Monitoring Instrument (OMI) were utilized to identify whether the studied areas would benefit more from reducing NO x emissions (NO xlimited) or VOC emissions (VOC-limited). Formaldehyde (HCHO) and nitrogen dioxide (NO 2 ) were chosen as markers of VOCs and NO x , respectively. The long-term monthly trends in the column NO 2 , HCHO, and surface O 3 , respectively, showed slopes of 3.59 × 10 12 ± 5.41 × 10 12 molecules cm −2 month −1 , 6.47 × 10 12 ± 3.61 × 10 12 molecules cm −2 month −1 , and 0.02 ± 0.02 ppb month −1 . Seasonal variations of O 3 showed similarities to those of NO 2 . Strong north-to-south gradients of −2.52 × 10 14 molecules cm −2 degree −1 , −4.07 × 10 14 molecules cm −2 degree −1 , and 1.004 ppb degree −1 were observed for NO 2 , HCHO, and O 3 , respectively. The seasonal variation in meteorological parameters was also examined to demonstrate effects on the ozone-forming sensitivity through a correlation study. Metropolitan cities (Dhaka, Chattogram, and Kolkata), big cities (Rajshahi, Khulna, and Barishal) except for Birbhum (16%), and oceanic sites were found to be the NO x -limited regime (64−98%). Increasing NO x sensitivity in all of the areas suggests that local NO x emission mitigation policies will improve the air quality and reduce ambient O 3 in the GBM delta region.

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“…To date, O 3 pollution has been found in most of Chinese areas, such as Beijing-Tianjin-Hebei region (BTH) (Li et al, 2015;Li et al, 2020), the Pearl River Delta (PRD) Zheng et al, 2010;Lin et al, 2019) and the Yangtze River Delta (YRD) (Wu et al, 2017;Liu et al, 2018). To reduce O 3 pollution, many measures have been taken by the Chinese government.…”

Section: Introductionmentioning

confidence: 99%

Assessment of the Characteristics and Influencing Factors of Ozone in Fuzhou, China, Using Wavelet Analysis

Luo

Zhang

et al. 2020

Aerosol Air Qual. Res.

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In recent years, ozone (O 3 ) air pollution has become a major problem-which is still increasing-in China. In this study, data on the O 3 concentration as well as on two of its influencing factors, meteorological parameters and traffic conditions, were collected in Fuzhou and then analyzed via wavelet transforms to evaluate the variation in O 3 concentration and its relationships with the factors. High concentrations appeared during spring and summer, and notable fluctuations occurred primarily from March till April, from June till July and during September. The level of O 3 exhibited significant positive correlations with the temperature and sunshine duration but negative ones with the relative humidity, precipitation and air pressure; additionally, it increased when the wind speed was low and fluctuated when the wind speed was high. The concentration was also significantly negatively correlated with the concentrations of O 3 precursors (NO x and CO) and hence closely related to the traffic conditions, as the reduced vehicle speed during rush hour due to increased vehicle flow and traffic density led to higher precursor emissions in the vehicular exhaust. A prominent "weekend effect" was observed with the precursor levels, which displayed greater fluctuations during the weekdays than the weekends; the vehicle flow and the O 3 concentration.

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Increase in Surface Ozone over Beijing-Tianjin-Hebei and the Surrounding Areas of China Inferred from Satellite Retrievals, 2005-2018

Cited by 18 publications

References 0 publications

Ozone Continues to Increase in East Asia Despite Decreasing NO2: Causes and Abatements

Ozone Continues to Increase in East Asia Despite Decreasing NO2: Causes and Abatements

Long-Term (2011–2019) Trends of O₃, NO₂, and HCHO and Sensitivity Analysis of O₃ Chemistry over the GBM (Ganges–Brahmaputra–Meghna) Delta: Spatial and Temporal Variabilities

Assessment of the Characteristics and Influencing Factors of Ozone in Fuzhou, China, Using Wavelet Analysis

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Increase in Surface Ozone over Beijing-Tianjin-Hebei and the Surrounding Areas of China Inferred from Satellite Retrievals, 2005-2018

Cited by 18 publications

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Ozone Continues to Increase in East Asia Despite Decreasing NO2: Causes and Abatements

Ozone Continues to Increase in East Asia Despite Decreasing NO2: Causes and Abatements

Long-Term (2011–2019) Trends of O3, NO2, and HCHO and Sensitivity Analysis of O3 Chemistry over the GBM (Ganges–Brahmaputra–Meghna) Delta: Spatial and Temporal Variabilities

Assessment of the Characteristics and Influencing Factors of Ozone in Fuzhou, China, Using Wavelet Analysis

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Long-Term (2011–2019) Trends of O₃, NO₂, and HCHO and Sensitivity Analysis of O₃ Chemistry over the GBM (Ganges–Brahmaputra–Meghna) Delta: Spatial and Temporal Variabilities