Vertical Characteristics of Pollution Transport in Hong Kong and Beijing, China

Transported pollution plays an important role in the atmospheric environment of eastern China. This study analyzed the characteristics of surface winds at different air quality levels using meteorological station observations of both wind and mass concentrations of particulate matter with aerodynamic diameters <2.5 μm (PM2.5) over Hong Kong and Beijing. In recent decades, wind directions at the surface exhibit a similar pattern for both good and poor air quality levels at all three stations, indicating a weak relationship between surface winds and air quality in Hong Kong. However, winds at a height of 1–2 km govern pollution accumulation. This dominant role is illustrated by a sudden change in wind direction within this layer and a simultaneous pollution accumulation stage on 8 January 2014. The controlling influence of winds at 1–2 km on both the deterioration and improvement of air quality is also supported by a distinct vertical wind distribution for all 21 monotonic increasing stages and 17 decreasing stages of PM2.5. In contrast, air pollution is transported to Beijing throughout the atmospheric layer that extends from the surface to a height of more than 3 km. This key difference may be due to variations in meteorology, topography, and emission sources between Hong Kong and Beijing. The results that layer of 1–2 km in Hong Kong and of surface to 3 km in Beijing is the height where pollution transport is most likely to occur are critical for forecasting severe haze episodes in eastern China.

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A Special Issue of Atmospheric Environment on “Improving Regional Air Quality over the Pearl River Delta and Hong Kong: From Science to Policy”

Atmospheric Environment ◽

10.1016/j.atmosenv.2013.05.036 ◽

2013 ◽

Vol 76 ◽

pp. 1-2 ◽

Cited By ~ 2

Author(s):

Peter K.K. Louie ◽

Liuju Zhong ◽

Junyu Allen Zheng ◽

Alexis K.H. Lau

Keyword(s):

Hong Kong ◽

Air Quality ◽

Pearl River Delta ◽

River Delta ◽

Atmospheric Environment ◽

Pearl River ◽

Special Issue ◽

The Pearl River Delta ◽

Regional Air Quality ◽

The Pearl River

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Spatial and Temporal Characteristics of Environmental Air Quality and Its Relationship with Seasonal Climatic Conditions in Eastern China during 2015–2018

International Journal of Environmental Research and Public Health ◽

10.3390/ijerph18094524 ◽

2021 ◽

Vol 18 (9) ◽

pp. 4524

Author(s):

Zhiyuan Wang ◽

Xiaoyi Shi ◽

Chunhua Pan ◽

Sisi Wang

Keyword(s):

Particulate Matter ◽

Air Quality ◽

Air Pollutants ◽

Large Scale ◽

Asian Summer Monsoon ◽

Eastern China ◽

Climatic Conditions ◽

Uniform Structure ◽

Concentration Limit ◽

Environmental Air

Exploring the relationship between environmental air quality (EAQ) and climatic conditions on a large scale can help better understand the main distribution characteristics and the mechanisms of EAQ in China, which is significant for the implementation of policies of joint prevention and control of regional air pollution. In this study, we used the concentrations of six conventional air pollutants, i.e., carbon monoxide (CO), sulfur dioxide (SO2), nitrogen dioxide (NO2), fine particulate matter (PM2.5), coarse particulate matter (PM10), and ozone (O3), derived from about 1300 monitoring sites in eastern China (EC) from January 2015 to December 2018. Exploiting the grading concentration limit (GB3095-2012) of various pollutants in China, we also calculated the monthly average air quality index (AQI) in EC. The results show that, generally, the EAQ has improved in all seasons in EC from 2015 to 2018. In particular, the concentrations of conventional air pollutants, such as CO, SO2, and NO2, have been decreasing year by year. However, the concentrations of particulate matter, such as PM2.5 and PM10, have changed little, and the O3 concentration increased from 2015 to 2018. Empirical mode decomposition (EOF) was used to analyze the major patterns of AQI in EC. The first mode (EOF1) was characterized by a uniform structure in AQI over EC. These phenomena are due to the precipitation variability associated with the East Asian summer monsoon (EASM), referred to as the “summer–winter” pattern. The second EOF mode (EOF2) showed that the AQI over EC is a north–south dipole pattern, which is bound by the Qinling Mountains and Huaihe River (about 35° N). The EOF2 is mainly caused by seasonal variations of the mixed concentration of PM2.5 and O3. Associated with EOF2, the Mongolia–Siberian High influences the AQI variation over northern EC by dominating the low-level winds (10 m and 850 hPa) in autumn and winter, and precipitation affects the AQI variation over southern EC in spring and summer.

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Roles of anthropogenic forcings in the observed trend of decreasing late-summer precipitation over the East Asian transitional climate zone

Scientific Reports ◽

10.1038/s41598-021-84470-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Wei Zhao ◽

Wen Chen ◽

Shangfeng Chen ◽

Hainan Gong ◽

Tianjiao Ma

Keyword(s):

Asian Summer Monsoon ◽

Dominant Role ◽

East Asian ◽

Eastern China ◽

Summer Precipitation ◽

Late Summer ◽

Water Vapor Transport ◽

Anthropogenic Aerosol ◽

Climate Zone ◽

Drying Trend

AbstractObservations indicate that late-summer precipitation over the East Asian transitional climate zone (TCZ) showed a pronounced decreasing trend during 1951–2005. This study examines the relative contributions of anthropogenic [including anthropogenic aerosol (AA) and greenhouse gas (GHG)] and natural forcings to the drying trend of the East Asian TCZ based on simulations from CMIP5. The results indicate that AA forcing plays a dominant role in contributing to the drying trend of the TCZ. AA forcing weakens the East Asian summer monsoon via reducing the land-sea thermal contrast, which induces strong low-level northerly anomalies over eastern China, suppresses water vapor transport from southern oceans and results in drier conditions over the TCZ. In contrast, GHG forcing leads to a wetting trend in the TCZ by inducing southerly wind anomalies, thereby offsetting the effect of the AA forcing. Natural forcing has a weak impact on the drying trend of the TCZ due to the weak response of atmospheric anomalies.

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Numerical air quality forecasting over eastern China: An operational application of WRF-Chem

Atmospheric Environment ◽

10.1016/j.atmosenv.2017.01.020 ◽

2017 ◽

Vol 153 ◽

pp. 94-108 ◽

Cited By ~ 32

Author(s):

Guangqiang Zhou ◽

Jianming Xu ◽

Ying Xie ◽

Luyu Chang ◽

Wei Gao ◽

...

Keyword(s):

Air Quality ◽

Eastern China ◽

Operational Application ◽

Air Quality Forecasting

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Pre-monsoon air quality over Lumbini, a world heritage site along the Himalayan foothills

10.5194/acp-2016-430 ◽

2016 ◽

Cited By ~ 2

Author(s):

Dipesh Rupakheti ◽

Bhupesh Adhikary ◽

Puppala S. Praveen ◽

Maheswar Rupakheti ◽

Shichang Kang ◽

...

Keyword(s):

Air Pollution ◽

Air Quality ◽

Forest Fires ◽

Air Pollutants ◽

Transport Model ◽

World Heritage ◽

World Heritage Site ◽

Pollution Level ◽

Pollution Transport ◽

Heritage Site

Abstract. Lumbini, in southern Nepal, is a UNESCO world heritage site of universal value as the birthplace of Buddha. Poor air quality in Lumbini and surrounding regions is a great concern for public health as well as for preservation, protection and promotion of Buddhist heritage and culture. We present here results from measurements of ambient concentrations of key air pollutants (PM, BC, CO, O3) in Lumbini, first of its kind for Lumbini, conducted during an intensive measurement period of three months (April–June 2013) in the pre-monsoon season. The measurements were carried out as a part of the international air pollution measurement campaign; SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley – Atmospheric Brown Clouds). The ranges of hourly average concentrations were: PM10: 10.5–604.0 µg m−3, PM2.5: 6.1–272.2 µg m−3; BC: 0.3–30.0 µg m−3; CO: 125.0–1430.0 ppbv; and O3: 1.0–118.1 ppbv. These levels are comparable to other very heavily polluted sites throughout South Asia. The 24-h average PM2.5 and PM10 concentrations exceeded the WHO guideline very frequently (94 % and 85 % of the sampled period, respectively), which implies significant health risks for the residents and visitors in the region. These air pollutants exhibited clear diurnal cycles with high values in the morning and evening. During the study period, the worst air pollution episodes were mainly due to agro-residue burning and regional forest fires combined with meteorological conditions conducive of pollution transport to Lumbini. Fossil fuel combustion also contributed significantly, accounting for more than half of the ambient BC concentration according to aerosol spectral light absorption coefficients obtained in Lumbini. WRF-STEM, a regional chemical transport model, was used to simulate the meteorology and the concentrations of pollutants. The model was able to reproduce the variation in the pollutant concentrations well; however, estimated values were 1.5 to 5 times lower than the observed concentrations for CO and PM10 respectively. Regionally tagged CO tracers showed the majority of CO came from the upwind region of Ganges valley. The model was also used to examine the chemical composition of the aerosol mixture, indicating that organic carbon was the main constituent of fine mode PM2.5, followed by mineral dust. Given the high pollution level, there is a clear and urgent need for setting up a network of long-term air quality monitoring stations in the greater Lumbini region.

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Increasing surface ozone concentrations in the background atmosphere of Southern China, 1994–2007

Atmospheric Chemistry and Physics ◽

10.5194/acp-9-6217-2009 ◽

2009 ◽

Vol 9 (16) ◽

pp. 6217-6227 ◽

Cited By ~ 277

Author(s):

T. Wang ◽

X. L. Wei ◽

A. J. Ding ◽

C. N. Poon ◽

K. S. Lam ◽

...

Keyword(s):

Hong Kong ◽

South China ◽

Surface Ozone ◽

Eastern China ◽

Rate Of Change ◽

Urban Site ◽

Coastal Regions ◽

Air Masses ◽

Background Ozone ◽

Rate Of Increase

Abstract. Tropospheric ozone is of great importance with regard to air quality, atmospheric chemistry, and climate change. In this paper we report the first continuous record of surface ozone in the background atmosphere of South China. The data were obtained from 1994 to 2007 at a coastal site in Hong Kong, which is strongly influenced by the outflow of Asian continental air during the winter and the inflow of maritime air from the subtropics in the summer. Three methods are used to derive the rate of change in ozone. A linear fit to the 14-year record shows that the ozone concentration increased by 0.58 ppbv/yr, whereas comparing means in years 1994–2000 and 2001–2007 gives an increase of 0.87 ppbv/yr for a 7-year period. The ozone changes in air masses from various source regions are also examined. Using local wind and carbon monoxide (CO) data to filter out local influence, we find that ozone increased by 0.94 ppbv/yr from 1994–2000 to 2001–2007 in air masses from Eastern China, with similar changes in the other two continent-influenced air-mass groups, but no statistically significant change in the marine air. An examination of the nitrogen dioxide (NO2) column obtained from GOME and SCIAMACHY reveals an increase in atmospheric NO2 in China's three fastest developing coastal regions, whereas NO2 in other parts of Asia decreased during the same period, and no obvious trend over the main shipping routes in the South China Sea was indicated. Thus the observed increase in background ozone in Hong Kong is most likely due to the increased emissions of NO2 (and possibly volatile organic compounds (VOCs) as well) in the upwind coastal regions of mainland China. The CO data at Hok Tsui showed less definitive changes compared to the satellite NO2 column. The increase in background ozone likely made a strong contribution (81%) to the rate of increase in "total ozone" at an urban site in Hong Kong, suggesting the need to consider distant sources when developing long-term strategies to mitigate local ozone pollution.

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Short‐Term Weather Patterns Modulate Air Quality in Eastern China During 2015–2016 Winter

Journal of Geophysical Research Atmospheres ◽

10.1029/2018jd029409 ◽

2019 ◽

Vol 124 (2) ◽

pp. 986-1002 ◽

Cited By ~ 2

Author(s):

Shuyu Zhao ◽

Tian Feng ◽

Xuexi Tie ◽

Wenting Dai ◽

Jiamao Zhou ◽

...

Keyword(s):

Air Quality ◽

Eastern China ◽

Short Term ◽

Weather Patterns

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A data-driven approach for optimal design of integrated air quality monitoring network in a chemical cluster

Royal Society Open Science ◽

10.1098/rsos.180889 ◽

2018 ◽

Vol 5 (9) ◽

pp. 180889 ◽

Cited By ~ 2

Author(s):

Zhengqiu Zhu ◽

Bin Chen ◽

Sihang Qiu ◽

Rongxiao Wang ◽

Yiping Wang ◽

...

Keyword(s):

Air Quality ◽

Measurement Data ◽

Monitoring Network ◽

Quality Monitoring ◽

Data Driven ◽

Atmospheric Environment ◽

Illustrative Case ◽

Air Quality Monitoring ◽

Detection Capability ◽

Data Driven Approach

The chemical industry is of paramount importance to the world economy and this industrial sector represents a substantial income source for developing countries. However, the chemical plants producing inside an industrial district pose a great threat to the surrounding atmospheric environment and human health. Therefore, designing an appropriate and available air quality monitoring network (AQMN) is essential for assessing the effectiveness of deployed pollution-controlling strategies and facilities. As monitoring facilities located at inappropriate sites would affect data validity, a two-stage data-driven approach constituted of a spatio-temporal technique (i.e. Bayesian maximum entropy) and a multi-objective optimization model (i.e. maximum concentration detection capability and maximum dosage detection capability) is proposed in this paper. The approach aims at optimizing the design of an AQMN formed by gas sensor modules. Owing to the lack of long-term measurement data, our developed atmospheric dispersion simulation system was employed to generate simulated data for the above method. Finally, an illustrative case study was implemented to illustrate the feasibility of the proposed approach, and results imply that this work is able to design an appropriate AQMN with acceptable accuracy and efficiency.

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Study on the Content and Influence of Heavy Metal Elements in Dust of Xiqing District of Tianjin

E3S Web of Conferences ◽

10.1051/e3sconf/202124801042 ◽

2021 ◽

Vol 248 ◽

pp. 01042

Author(s):

YanShan Yin ◽

Jin Xu

Keyword(s):

Heavy Metal ◽

Air Quality ◽

Human Health ◽

Inductively Coupled Plasma ◽

Great Influence ◽

Electric Heating ◽

Atmospheric Environment ◽

Total Dust ◽

Metal Elements ◽

Heavy Metal Elements

At present, heavy metal elements in dust have great influence on air quality and human health,therefore, the content and influence of heavy metal elements on campus were studied. Firstly, PM10 and total dust in the autumn campus atmosphere were sampled for 10 consecutive days, and then digested by electric heating plate digestion method. Then, inductively coupled plasma emission spectrometer (ICP-OES) was used to detect and analyze the content and concentration ratio of seven heavy metal elements Cu, Pb, Cd, Zn, Cr, Hg and Ba in PM10 and total dust. Finally, through comparative analysis, it is concluded that heavy metal pollutants in the atmospheric environment are mainly Zn and Ba, and the concentrations of Cd, Zn and Ba are seriously exceeded, so the air quality in Xiqing District of Tianjin is poor, and the particle size distribution of Cd and Hg makes it easy to enter the human body, which is especially unfavorable to human health.

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