PM2.5 and O3 pollution during 2015–2019 over 367 Chinese cities: Spatiotemporal variations, meteorological and topographical impacts

Environmental Pollution, Journal Year: 2020, Volume and Issue: 264, P. 114694 - 114694

Published: May 5, 2020

Language: Английский

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Meteorological influences on PM2.5 and O3 trends and associated health burden since China's clean air actions

The Science of The Total Environment, Journal Year: 2020, Volume and Issue: 744, P. 140837 - 140837

Published: July 13, 2020

Stringent clean air actions have been implemented to improve quality in China since 2013. In addition anthropogenic emission abatements, the changes may be modulated also by meteorology. this study, we developed multiple linear regression models quantify meteorological influences on trends fine particulate matter (PM2.5) and ozone (O3) concentrations associated health burden over three polluted regions of China, i.e., North Plain, Yangtze River Delta, Fen-wei Plain during 2014-2018, with a novel focus contributions most influential factors PM2.5 O3 as well PM2.5- O3-related mortality trends. The meteorology-driven for were -0.5~-2.0 (+0.7~+0.8) μg m-3 yr-1, contributing 10- 26% (12- 18%) observed five-year decreasing (increasing O3) decreased relative humidity (increased daytime planetary boundary layer height) was identified factor explained 55% (42%) largest trend among all seasons. decreases (increases led overall PM2.5-related O3-related) mortalities -2.2~-7.4 (+0.5~+0.9) thousand yr-1 regions, accounting (15- 31%) total (increasing) (O3-related) mortalities. results emphasize important role meteorology implications China's planning. particular, more efforts control should taken offset adverse effects caused

Language: Английский

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Record-breaking dust loading during two mega dust storm events over northern China in March 2021: aerosol optical and radiative properties and meteorological drivers

Atmospheric chemistry and physics, Journal Year: 2022, Volume and Issue: 22(12), P. 7905 - 7932

Published: June 17, 2022

Abstract. Although a remarkable reduction in the frequency of sand and dust storms (SDSs) past several decades has been reported over northern China (NC), two unexpected mega SDSs occurred on 15–20 27–29 March 2021 (abbreviated as “3.15” “3.27” SDS events), which reawakened widespread concern. This study characterizes optical, microphysical, radiative properties aerosols their meteorological drivers during these events using Sun photometer observations Beijing comprehensive set multiple satellite (including MODIS, VIIRS, CALIOP, Himawari-8) ground-based CMA visibility network AD-Net) combined with atmospheric reanalysis data. Moreover, long-term (2000–2021) optical depth (DOD) dataset retrieved from MODIS measurements was also utilized to evaluate historical ranking loading NC events. During 3.15 3.27 events, invasion plumes greatly degraded large areas NC, extreme low 50 500 m recorded at most sites 15 28 March, respectively. Despite shorter duration event relative event, sun larger peak AOD (∼2.5) former than latter (∼2.0), mainly attributed short-term intrusion coarse-mode particles effective radii (∼1.9 µm) volume concentrations (∼2.0 µm3 µm−2) event. The shortwave direct aerosol forcing induced by estimated be −92.1 −111.4 W m−2 top atmosphere, −184.7 −296.2 surface, +92.6 +184.8 atmosphere CALIOP show that plume lifted an altitude 4–8 km, its range impact extended source eastern coast China. In contrast, lifting height lower confirmed lidar observations. MODIS-retrieved DOD data registered massive intense episode same period history 2 decades. These were associated both circulation extremes local anomalies favored enhanced emissions Gobi Desert (GD) across southern Mongolia NC. Meteorological analysis revealed triggered exceptionally strong Mongolian cyclone generated nearly location (along central plateau Inner Mongolia) conjunction surface-level cold high-pressure system rear, albeit differences magnitude spatial extent impact. GD, early melting spring snow caused near-surface temperature regions, together negative soil moisture decreased precipitation, formed drier barer surfaces, allowed for increased into strongly surface winds cyclone.

Language: Английский

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Construction of a virtual PM2.5 observation network in China based on high-density surface meteorological observations using the Extreme Gradient Boosting model

Environment International, Journal Year: 2020, Volume and Issue: 141, P. 105801 - 105801

Published: May 30, 2020

With increasing public concerns on air pollution in China, there is a demand for long-term continuous PM2.5 datasets. However, it was not until the end of 2012 that China established national observation network. Before that, satellite-retrieved aerosol optical depth (AOD) frequently used as primary predictor to estimate surface PM2.5. Nevertheless, AOD often encounter incomplete daily coverage due its sampling frequency and interferences from cloud, which greatly affect representation these AOD-based Here, we constructed virtual ground-based network at 1180 meteorological sites across using Extreme Gradient Boosting (XGBoost) model with high-density observations major predictors. Cross-validation XGBoost showed strong robustness high accuracy estimation (monthly) 2018, R2, root-mean-square error (RMSE) mean absolute values 0.79 (0.92), 15.75 μg/m3 (6.75 μg/m3) 9.89 (4.53 μg/m3), respectively. Meanwhile, find visibility plays dominant role terms relative importance variables model, accounting 39.3% overall importance. We then use data year 2017 assess predictive capability model. Results capable accurately hindcast historical monthly (R2 = 0.80, RMSE 14.75 seasonal 0.86, 12.28 annual 0.81, 10.10 levels. In general, newly based shows great potential reconstructing ~1000 China. It will be benefit filling gaps data, well other environmental studies including epidemiology.

Language: Английский

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Spatial distribution of aerosol microphysical and optical properties and direct radiative effect from the China Aerosol Remote Sensing Network

Atmospheric chemistry and physics, Journal Year: 2019, Volume and Issue: 19(18), P. 11843 - 11864

Published: Sept. 24, 2019

Abstract. Multi-year observations of aerosol microphysical and optical properties, obtained through ground-based remote sensing at 50 China Aerosol Remote Sensing Network (CARSNET) sites, were used to characterize the climatology for representative remote, rural, urban areas over assess effects on climate. The annual mean effective radii total particles (ReffT) decreased from north south rural high particle volumes found sites. depth 440 nm (AOD440 nm) increased sites (0.12) (0.79), extinction Ångström exponent (EAE440–870 0.71 arid semi-arid 1.15 presumably due anthropogenic emissions. Single-scattering albedo (SSA440 ranged 0.88 0.92, indicating slightly strongly absorbing aerosols. Absorption AOD440 values 0.01 versus 0.07 average direct radiative effect (DARE) bottom atmosphere in (−24.40 W m−2) (−103.28 m−2), cooling latter. DARE top −4.79 m−2 −30.05 overall Earth–atmosphere system. A classification method based SSA440 nm, fine-mode fraction (FMF), EAE440–870 showed that coarse-mode (mainly dust) dominant near northwestern deserts, while light-absorbing, important most This study will be understanding climate regional environmental pollution, results provide useful information satellite validation improvement modelling.

Language: Английский

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Evaluation of climate model aerosol trends with ground-based observations over the last 2 decades – an AeroCom and CMIP6 analysis

Atmospheric chemistry and physics, Journal Year: 2020, Volume and Issue: 20(21), P. 13355 - 13378

Published: Nov. 11, 2020

Abstract. This study presents a multiparameter analysis of aerosol trends over the last 2 decades at regional and global scales. Regional time series have been computed for set nine optical, chemical-composition mass properties by using observations from several ground-based networks. From these derived different regions world. Most related to loading exhibit negative trends, both surface in total atmospheric column. Significant decreases optical depth (AOD) are found Europe, North America, South Africa Asia, ranging −1.2 % yr−1 −3.1 yr−1. An error representativity spatially temporally limited observational data has performed model subsets order investigate how much observed represent actual happening full period 2000 2014. reveals that significant uncertainty is associated with some due space sampling deficiencies. The then used evaluation 10 models (6 AeroCom phase III 4 CMIP6 models) CAMS reanalysis dataset their skills reproducing trends. Model performance vary depending on parameters tend capture AOD, column Ångström exponent, sulfate particulate matter well (except Africa), but they show larger discrepancies coarse-mode AOD. rather good agreement across between observations, when co-locating them space, implies including those poorly monitored regions, likely correct. can help provide picture filling gaps not covered observations. calculation scale depicted solely relying Using complete diagnostics (NorESM2), we find increase AOD about 0.2 2014, primarily caused an loads organic aerosols, black carbon.

Language: Английский

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Identifying a transport mechanism of dust aerosols over South Asia to the Tibetan Plateau: A case study

The Science of The Total Environment, Journal Year: 2020, Volume and Issue: 758, P. 143714 - 143714

Published: Nov. 14, 2020

Language: Английский

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Long-Term Variability of Dust Events in Southwestern Iran and Its Relationship with the Drought

Atmosphere, Journal Year: 2021, Volume and Issue: 12(10), P. 1350 - 1350

Published: Oct. 15, 2021

Dust storms represent a major environmental challenge in the Middle East. The southwest part of Iran is highly affected by dust events transported from neighboring desert regions, mostly Iraqi plains and Saudi Arabia, as well local storms. This study analyzes spatio-temporal distribution days at five meteorological stations located southwestern covering period 22 years (from 1997 to 2018). codes (06, 07, 30 35) observations are analyzed each station, indicating that 84% not origin. average number maximizes June July (188 193, respectively), while activity weakens after August. exhibit large inter-annual variability, with statistically significant increasing trends all stations. Spatial distributions aerosol optical depth (AOD), loading, surface concentrations moderate resolution imaging spectroradiometer (MODIS) Modern-Era Retrospective analysis for Research Applications (MERRA-2) retrievals reveal high accumulation over surrounding regions. Furthermore, spatial (MODIS)-AOD trend (%) indicates heterogeneity during 2000–2018 ranging between −9% 9% (not significant). 2009 was most active year, followed 2011 2008, due prolonged drought conditions fertile crescent enhanced emissions this period. In these years, AOD much higher than 19-year (2000 2018), dustiest month about 25–30 station. highest were associated less precipitation, negative anomalies vegetation health index (VHI) normalized difference (NDVI) Iran, favorable dynamics triggering stronger winds.

Language: Английский

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Distinct spatiotemporal variation patterns of surface ozone in China due to diverse influential factors

Journal of Environmental Management, Journal Year: 2021, Volume and Issue: 288, P. 112368 - 112368

Published: March 24, 2021

Language: Английский

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Numerical simulations of dust storms originated from dried lakes in central and southwest Asia: The case of Aral Sea and Sistan Basin

Aeolian Research, Journal Year: 2021, Volume and Issue: 50, P. 100679 - 100679

Published: Feb. 6, 2021

Language: Английский

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