Synergistic effects of biogenic volatile organic compounds and soil nitric oxide emissions on summertime ozone formation in China

The Science of The Total Environment, Год журнала: 2022, Номер 828, С. 154218 - 154218

Опубликована: Март 1, 2022

Язык: Английский

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Field Detection of Highly Oxygenated Organic Molecules in Shanghai by Chemical Ionization–Orbitrap

Environmental Science & Technology, Год журнала: 2022, Номер 56(12), С. 7608 - 7617

Опубликована: Май 20, 2022

Secondary organic aerosol, formed through atmospheric oxidation processes, plays an important role in affecting climate and human health. In this study, we conducted a comprehensive campaign the megacity of Shanghai during 2019 International Import Expo (EXPO), with first deployment chemical ionization─Orbitrap mass spectrometer for ambient measurements. With ultrahigh resolving power Orbitrap analyzer (up to 140,000 Th/Th) capability dealing massive spectral data sets by positive matrix factorization, were able identify major gas-phase processes leading formation oxygenated molecules (OOM) Shanghai. Nine main factors from three independent sub-range analysis identified. More than 90% OOM are anthropogenic origin >60% nitrogen-containing molecules, mainly dominated RO2 + NO and/or NO3 chemistry. The emission control EXPO showed that even though restriction was effectual significantly lowering primary pollutants (20–70% decrease), secondary products responded less effectively (14% or increased (50 >200%) due enhancement ozone lowered condensation sink, indicating importance stricter multi-pollutant coordinated strategy pollution mitigation.

Язык: Английский

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Impact of atmospheric thermodynamic structures and aerosol radiation feedback on winter regional persistent heavy particulate pollution in the Sichuan-Chongqing region, China

The Science of The Total Environment, Год журнала: 2022, Номер 842, С. 156575 - 156575

Опубликована: Июнь 7, 2022

Язык: Английский

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

Frontiers in Environmental Science, Год журнала: 2022, Номер 10

Опубликована: Фев. 18, 2022

Surface ozone (O 3 ) increased by ∼20% in the Yangtze River Delta (YRD) region of China during 2014–2020, but aggravating trend is highly variable on interannual time and city-level space scales. Here, we employed multiple air quality observations numerical simulation to describe increasing O reveal main driving factors behind it. In 2014–2017, governmental pollution control action plan was mostly against PM 2.5 (mainly emissions SO 2 , NO x primary effectively reduced concentration 18%–45%. However, worsened same period with an rate 4.9 μg m −3 yr −1 especially Anhui province, where growth even reached 14.7 . After 2018, owing coordinated prevention both volatile organic compound (VOC) YRD has also been controlled a great concern, obviously alleviated (1.1 ). We further combined precursor corresponding formation regime explain observed 2014–2020. The leading 2014–2017 diagnosed as VOC-limited (21%) or mix-limited (58%), help simulated indicator HCHO/NO y Under such condition, decreasing (2.8% VOCs (3.6% led rapid increment With continuous reduction emission ambient /VOCs, production along shifting from mix-limited, after become dominant for 55% cities. Consequently, decreases (3.3% (7.7% 2018–2020 slowed down Our study argues that implementation regional VOCs, effective emerging region.

Язык: Английский

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Vertical exchange and cross-regional transport of lower-tropospheric ozone over Hong Kong

Atmospheric Research, Год журнала: 2023, Номер 292, С. 106877 - 106877

Опубликована: Июнь 15, 2023

In recent years, the escalating ozone concentrations in urban areas of China have raised significant public concern. Due to lack long-term vertical observation, characteristics distribution and long-range transport are still not well understood. This study utilized 27 years (1994–2020) sounding observations Hong Kong, conjunction with ERA5 reanalysis data HYSPLIT backward model, examine structure three-dimensional cross-regional tropospheric over Kong. During spring, above 850 hPa found be higher than those observed during other seasons. Conversely, below comparatively elevated autumn. The stratospheric-tropospheric exchange (STE) process is a crucial factor contributing high upper troposphere, 46.2% trajectories crossing tropopause becoming concentrated mainly eastern Yunnan–Guizhou Plateau. identified two obvious peaks lower troposphere at approximately 700 hPa. springtime maximum linked from elevations Bay Bengal Indo–China Peninsula, which moves eastward downward under influence southern branch trough. Additionally, transboundary transportation fire emissions Southeast Asia, influenced by monsoon circulation, also contributes observation. autumn occurrs 925 boundary layer dynamics southward low-altitude Pearl River Delta Yangtze regions northeasterly Asian flow. advances our knowledge understanding profile emphasizes importance regionally-joint emission control particularly when meteorology-induced occurs.

Язык: Английский

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Parsimonious estimation of hourly surface ozone concentration across China during 2015–2020

Scientific Data, Год журнала: 2024, Номер 11(1)

Опубликована: Май 14, 2024

Abstract Surface ozone is an important air pollutant detrimental to human health and vegetation productivity, particularly in China. However, high resolution surface concentration data still lacking, largely hindering accurate assessment of associated environmental impacts. Here, we collected hourly ground observations (over 6 million records), remote sensing products, meteorological data, social-economic information, applied recurrent neural networks map (HrSOD) at a 0.1° × across China during 2015–2020. The coefficient determination (R 2 ) values sample-based, site-based, by-year cross-validations were 0.72, 0.65 0.71, respectively, with the root mean square error (RMSE) being 11.71 ppb (mean = 30.89 ppb), 12.81 30.96 ppb) 11.14 31.26 ppb). Moreover, it exhibits spatiotemporal consistency ground-level different time scales (diurnal, seasonal, annual), various spatial levels (individual sites regional scales). Meanwhile, HrSOD provides critical information for fine-resolution impacts on benefits.

Язык: Английский

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Atmospheric Oxidation Capacity Elevated during 2020 Spring Lockdown in Chengdu, China: Lessons for Future Secondary Pollution Control

Environmental Science & Technology, Год журнала: 2024, Номер 58(20), С. 8815 - 8824

Опубликована: Май 11, 2024

This study presents the measurement of photochemical precursors during lockdown period from January 23, 2020, to March 14, in Chengdu response coronavirus (COVID-19) pandemic. To derive impact on air quality, observations are compared equivalent periods last 2 years. An observation-based model is used investigate atmospheric oxidation capacity change lockdown. OH, HO2, and RO2 concentrations simulated, which elevated by 42, 220, 277%, respectively, period, mainly due reduction nitrogen oxides (NOx). However, radical turnover rates, i.e., OH rate L(OH) local ozone production P(O3), determine secondary intermediates formation O3 formation, only increase 24 48%, respectively. Therefore, increases slightly lockdown, partly attributed unchanged alkene concentrations. During ozonolysis seems be a significant primary source unique data set highlights importance controlling emission mitigate pollution may also applicable other regions China given an expected NOx rapid transformation electrified fleets future.

Язык: Английский

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The Impact of COVID-19 Lockdowns on Air Quality—A Global Review

Sustainability, Год журнала: 2021, Номер 13(18), С. 10212 - 10212

Опубликована: Сен. 13, 2021

The outbreak of the COVID-19 pandemic has emerged as a serious public health threat and had tremendous impact on all spheres environment. air quality across world improved because lockdowns. Since COVID-19, large numbers studies have been carried out lockdowns around world, but no systematic review quality. This study aims to systematically assess bibliographic globe. A total 237 were identified after rigorous review, 144 met criteria for review. literature was surveyed from Scopus, Google Scholar, PubMed, Web Science, search engine. results reveal that (i) most Asia (about 65%), followed by Europe (18%), North America (6%), South (5%), Africa (3%); (ii) in case countries, highest number performed India (29%), China (23%), U.S. UK (4%), Italy; (iii) more than 60% included NO2 study, PM2.5 50%), PM10, SO2, CO; (iv) published Science Total Environment Aerosol Air Quality Research Quality, Atmosphere & Health (9%), Environmental Pollution (5%); (v) there significant improvements during comparison with previous time periods. Thus, this diversified conducted will surely assist identifying any gaps, it outlines insights current scientific research.

Язык: Английский

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Assessment of the effect of meteorological and emission variations on winter PM2.5 over the North China Plain in the three-year action plan against air pollution in 2018–2020

Atmospheric Research, Год журнала: 2022, Номер 280, С. 106395 - 106395

Опубликована: Авг. 16, 2022

Язык: Английский

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Examining the implications of photochemical indicators for O₃–NO_x–VOC sensitivity and control strategies: a case study in the Yangtze River Delta (YRD), China

Atmospheric chemistry and physics, Год журнала: 2022, Номер 22(22), С. 14799 - 14811

Опубликована: Ноя. 22, 2022

Abstract. Ozone (O3) has become a significant air pollutant in China recent years. O3 abatement is challenging due to the nonlinear response of precursors nitrogen oxides (NOx) and volatile organic compounds (VOCs). Photochemical indicators are widely used estimate O3–NOx–VOC sensitivity, this important policy implications. However, effectiveness seldom been evaluated. This study examined applications four that include ratio production rates H2O2 HNO3 (PH2O2/PHNO3), HCHO/NO2, HCHO/NOy, reactive (NOy) Yangtze River Delta (YRD) with localized thresholds. The overall accuracy was high (>92 %) for all not significantly reduced different simulation periods or locations region. By comparing isopleths, it found HCHO/NO2 HCHO/NOy showed most consistency, whereas PH2O2/PHNO3 tended underestimate (overestimate) positive NOx. Additionally, less likely attribute formation mixed sensitivity than other indicators, demonstrated preference single-pollutant control strategy. also revealed details methodology derive threshold values impacted results, may produce uncertainties application photochemical indicators.

Язык: Английский

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