scholarly journals Supplementary material to "Impacts of aerosol-photolysis interaction and aerosol-radiation feedback on surface-layer ozone in North China during a multi-pollutant air pollution episode"

2021 ◽  
Author(s):  
Hao Yang ◽  
Lei Chen ◽  
Hong Liao ◽  
Jia Zhu ◽  
Wenjie Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
Surface Layer ◽  
North China ◽  
Pollution Episode ◽  
Supplementary Material ◽  
Radiation Feedback

scholarly journals Impacts of aerosol-photolysis interaction and aerosol-radiation feedback on surface-layer ozone in North China during a multi-pollutant air pollution episode

2021 ◽  
Author(s):  
Hao Yang ◽  
Lei Chen ◽  
Hong Liao ◽  
Jia Zhu ◽  
Wenjie Wang ◽  
...  
Keyword(s):  
Air Pollution ◽  
Surface Layer ◽  
North China ◽  
Process Analysis ◽  
Shortwave Radiation ◽  
Pollution Episode ◽  
Downward Shortwave Radiation ◽  
Photolysis Rates ◽  
Analysis Scheme ◽  
Radiation Feedback

Abstract. We examined the impacts of aerosol-radiation interactions, including the effects of aerosol-photolysis interaction (API) and aerosol-radiation feedback (ARF), on surface-layer ozone (O3) concentrations during one multi-pollutant air pollution episode characterized by high O3 and PM2.5 levels from 28 July to 3 August 2014 in North China, by using the Weather Research and Forecasting with Chemistry (WRF-Chem) model embedded with an integrated process analysis scheme. Our results show that aerosol-radiation interactions decrease the daytime downward shortwave radiation at surface, 2 m temperature, 10 m wind speed, planetary boundary layer height, photolysis rates J[NO2] and J[O1D] by 115.8 W m−2, 0.56 °C, 0.12 m s−1, 129 m, 1.8 × 10−3 s−1 and 6.1 × 10−6 s−1, and increase relative humidity at 2 m and downward shortwave radiation in the atmosphere by 2.4 % and 72.8 W m−2. The weakened photolysis rates and changed meteorological conditions reduce surface-layer O3 concentrations by up to 11.4 ppb (13.5 %), with API and ARF contributing 74.6 % and 25.4 % of the O3 decrease, respectively. The combined impacts of API and ARF on surface O3 are further quantitatively characterized by the ratio of changed O3 concentration to local PM2.5 level. The ratio is calculated to be −0.14 ppb (µg m−3)−1 averaged over the multi-pollutant air pollution area in North China. Process analysis indicates that the weakened O3 chemical production makes the greatest contribution to API effect while the reduced vertical mixing is the key process for ARF effect. This study implies that future PM2.5 reductions will lead to O3 increases due to weakened aerosol-radiation interactions. Therefore, tighter controls of O3 precursors are needed to offset O3 increases caused by weakened aerosol-radiation interactions in the future.

scholarly journals Impacts of meteorology and emission variations on the heavy air pollution episode in North China around the 2020 Spring Festival

2021 ◽  
Vol 64 (2) ◽  
pp. 329-339
Author(s):  
Wenbo Xue ◽  
Xurong Shi ◽  
Gang Yan ◽  
Jinnan Wang ◽  
Yanling Xu ◽  
...  
Keyword(s):  
Air Pollution ◽  
North China ◽  
Pollution Episode ◽  
Spring Festival

Association of exposure to ambient air pollution with ovarian reserve among women in Shanxi province of north China

2021 ◽  
Vol 278 ◽  
pp. 116868
Author(s):  
Xiaoqin Feng ◽  
Jinhong Luo ◽  
Xiaocheng Wang ◽  
Wolong Xie ◽  
Jiao Jiao ◽  
...  
Keyword(s):  
Air Pollution ◽  
Ovarian Reserve ◽  
North China ◽  
Ambient Air ◽  
Ambient Air Pollution ◽  
Shanxi Province

scholarly journals Impact of crop field burning and mountains on heavy haze in the North China Plain: A case study

2016 ◽  
Author(s):  
X. Long ◽  
X. X. Tie ◽  
J. J. Cao ◽  
R. J. Huang ◽  
T. Feng ◽  
...  
Keyword(s):  
Air Pollution ◽  
North China Plain ◽  
North China ◽  
Wind Condition ◽  
Beijing City ◽  
The North ◽  
The North China Plain ◽  
Crop Field ◽  
The Impact ◽  
Field Burning

Abstract. Crop field burning (CFB) has important effects on air pollution in China, but it is seldom quantified and reported in a regional scale, which is of great importance for the control strategies of CFB in China, especially in the North China Plain (NCP). With the provincial statistical data and open crop fires captured by satellite (MODIS), we extracted a detailed emission inventory of CFB during a heavy haze event from 6th to 12th October 2014. A regional dynamical and chemical model (WRF-Chem) was applied to investigate the impact of CFB on air pollution in NCP. The model simulations were compared with the in situ measurements of PM2.5 (particular matter with radius less than 2.5 μm) concentrations. The model evaluation shows that the correlation coefficients (R) between measured and calculated values exceeds 0.80 and absolute normalized mean bias (NMB) is no more than 14 %. In addition, the simulated meteorological parameters such as winds and planetary boundary layer height (PBLH) are also in good agreement with observations. The model was intensive used to study (1) the impacts of CFB and (2) the effect of mountains on regional air quality. The results show that the CFB occurred in southern NCP (SNCP) had significant effect on PM2.5 concentrations locally, causing a maximum of 35 % PM2.5 increase in SNCP. Because of south wind condition, the CFB pollution plume is subjective a long transport to northern NCP (NNCP-with several mega cities, including Beijing of the capital city in China), where there are no significant CFB occurrences, causing a maximum of 32 % PM2.5 increase in NNCP. As a result, the heavy haze in Beijing is enhanced by the CFB occurred in SNCP. Further more, there are two major mountains located in the western and northern NCP. Under the south wind condition, these mountains play important roles in enhancing the PM2.5 pollution in NNCP through the blocking and guiding effects. This study suggests that the PM2.5 emissions in SNCP region should be significantly limited in order to reduce the occurrences of heavy haze events in NNCP region, including the Beijing City.

scholarly journals Relationships between the planetary boundary layer height and surface pollutants derived from lidar observations over China

2018 ◽  
Author(s):  
Tianning Su ◽  
Zhanqing Li ◽  
Ralph Kahn
Keyword(s):  
Boundary Layer ◽  
Air Pollution ◽  
Negative Correlation ◽  
North China Plain ◽  
North China ◽  
Planetary Boundary Layer Height ◽  
Layer Height ◽  
Boundary Layer Height ◽  
The North ◽  
The North China Plain

Abstract. The frequent occurrence of severe air pollution episodes in China has raised great concerns with the public and scientific communities. Planetary boundary layer height (PBLH) is a key factor in the vertical mixing and dilution of near-surface pollutants. However, the relationship between PBLH and surface pollutants, especially particulate matter (PM) concentration, across the whole of China, is not yet well understood. We investigate this issue at ~ 1500 surface stations using PBLH derived from space-borne and ground-based lidar, and discuss the influence of topography and meteorological variables on the PBLH-PM relationship. A generally negative correlation is observed between PM and the PBLH, albeit varying greatly in magnitude with location and season. Correlations are much weaker over the highlands than plains regions, which may be associated with lower pollution levels and mountain breezes. The influence of horizontal transport on surface PM is considered as well, manifested as a negative correlation between surface PM and wind speed over the whole nation. Strong wind with clean upwind sources plays a dominant role in removing pollutants, and leads to weak PBLH-PM correlation. A ventilation rate is introduced to jointly consider horizontal and vertical dispersion, which has the largest impact on surface pollutant accumulation over the North China Plain. Aerosol absorption feedbacks also appear to affect the PBLH-PM relationship, as revealed via comparing air pollution in Beijing and Hong Kong. Absorbing aerosols in high concentrations likely contribute to the significant PBLH-PM correlation over the North China Plain (e.g., during winter). As major precursor emissions for secondary aerosols, sulfur dioxide, nitrogen dioxide, and carbon monoxide have similar negative responses to increased PBLH, whereas ozone is positively correlated with PBLH over most regions, which may be caused by heterogeneous reactions and photolysis rates.

scholarly journals Transport, mixing and feedback of dust, biomass burning and anthropogenic pollutants in eastern Asia: a case study

2018 ◽  
Vol 18 (22) ◽  
pp. 16345-16361 ◽  
Author(s):  
Derong Zhou ◽  
Ke Ding ◽  
Xin Huang ◽  
Lixia Liu ◽  
Qiang Liu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Biomass Burning ◽  
Southern China ◽  
Eastern China ◽  
Measurement Data ◽  
Lower Troposphere ◽  
Climate Impacts ◽  
Eastern Asia ◽  
Pollution Episode ◽  
The Yrd

Abstract. Anthropogenic fossil fuel (FF) combustion, biomass burning (BB) and desert dust are the main sources of air pollutants around the globe but are particularly intensive and important for air quality in Asia in spring. In this study, we investigate the vertical distribution, transport characteristics, source contribution and meteorological feedback of these aerosols in a unique pollution episode that occurred in eastern Asia based on various measurement data and modeling methods. In this episode, the Yangtze River Delta (YRD) in eastern China experienced persistent air pollution, dramatically changing from secondary fine particulate pollution to dust pollution in late March 2015. The Eulerian and Lagrangian models were conducted to investigate the vertical structure, transport characteristics and mechanisms of the multi-scale, multisource and multiday air pollution episode. The regional polluted continental aerosols mainly accumulated near the surface, mixed with dust aerosol downwash from the upper planetary boundary layer (PBL) and middle–lower troposphere (MLT), and further transported by large-scale cold fronts and warm conveyor belts. BB smoke from Southeast Asia was transported by westerlies around the altitude of 3 km from southern China, was further mixed with dust and FF aerosols in eastern China and experienced long-range transport over the Pacific. These pollutants could all be transported to the YRD region and cause a structure of multilayer pollution there. These pollutants could also cause significant feedback with MLT meteorology and then enhance local anthropogenic pollution. This study highlights the importance of intensive vertical measurement in eastern China and the downwind Pacific Ocean and raises the need for quantitative understanding of environmental and climate impacts of these pollution sources.

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