scholarly journals Effects of urban land expansion on the regional meteorology and air quality of Eastern China

2015 ◽  
Vol 15 (7) ◽  
pp. 10299-10340 ◽  
Author(s):  
W. Tao ◽  
J. Liu ◽  
G. A. Ban-Weiss ◽  
D. A. Hauglustaine ◽  
L. Zhang ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Urban Expansion ◽  
Eastern China ◽  
Urban Land ◽  
Pollutant Emissions ◽  
Ozone Pollution ◽  
Rapid Urbanization ◽  
Local Climate ◽  
Analysis Scheme

Abstract. Rapid urbanization throughout Eastern China is imposing an irreversible effect on local climate and air quality. In this paper, we examine the response of a range of meteorological and air quality indicators to urbanization. Our study uses the Weather Research and Forecasting model coupled with Chemistry (WRF/Chem) to simulate the climate and air quality impacts of four hypothetical urbanization scenarios with fixed surface pollutant emissions during the month of July from 2008 to 2012. An improved integrated process rate (IPR) analysis scheme is implemented in WRF/Chem to investigate the mechanisms behind the forcing–response relationship at the process level. For all years, as urban land area expands, concentrations of CO, elemental carbon (EC), and particulate matter with aerodynamic diameter less than 2.5 microns (PM2.5) tend to decrease near the surface (below ~ 500 m), but increase at higher altitudes (1–3 km), resulting in a reduced vertical concentration gradient. On the other hand, the O3 burden averaged over all newly urbanized grid cells consistently increases from the surface to a height of about 4 km. Sensitivity tests show that the response of meteorology and pollutant concentrations to the spatial extent of urbanization are nearly linear near the surface, but nonlinear at higher altitudes. Over eastern China, each 10% increase in nearby urban land coverage (NULC) on average leads to a decrease of approximately 2% in surface concentrations for CO, EC, and PM2.5, while for O3 an increase of about 1% is simulated. At 800 hPa, each 10% increase in the square of NULC enhances air pollution concentrations by 5–10%, depending on species. This indicates that as large tracts of new urban land emerge, the influence of urban expansion on meteorology and air pollution would be amplified. IPR results indicate that, for primary pollutants, the enhanced sink (source) caused by turbulent mixing and vertical advection in the lower (upper) atmosphere could be a key factor in changes to simulated vertical profiles. The evolution of secondary pollutants is further influenced by the upward relocation of precursors that impact gas phase chemistry for O3 and aerosol processes for PM2.5. Our study indicates that dense urbanization has a moderate dilution effect on surface primary airborne contaminants, but may intensify severe haze and ozone pollution if local emissions are not well controlled.

scholarly journals Effects of urban land expansion on the regional meteorology and air quality of eastern China

2015 ◽  
Vol 15 (15) ◽  
pp. 8597-8614 ◽  
Author(s):  
W. Tao ◽  
J. Liu ◽  
G. A. Ban-Weiss ◽  
D. A. Hauglustaine ◽  
L. Zhang ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Expansion ◽  
Eastern China ◽  
Urban Land ◽  
Pollutant Emissions ◽  
Ozone Pollution ◽  
Rapid Urbanization ◽  
Local Climate ◽  
Analysis Scheme ◽  
Concentration Changes

Abstract. Rapid urbanization throughout eastern China is imposing an irreversible effect on local climate and air quality. In this paper, we examine the response of a range of meteorological and air quality indicators to urbanization. Our study uses the Weather Research and Forecasting model coupled with chemistry (WRF/Chem) to simulate the climate and air quality impacts of four hypothetical urbanization scenarios with fixed surface pollutant emissions during the month of July from 2008 to 2012. An improved integrated process rate (IPR) analysis scheme is implemented in WRF/Chem to investigate the mechanisms behind the forcing–response relationship at the process level. For all years, as urban land area expands, concentrations of CO, elemental carbon (EC), and particulate matter with aerodynamic diameter less than 2.5 microns (PM2.5) tend to decrease near the surface (below ~ 500 m), but increase at higher altitudes (1–3 km), resulting in a reduced vertical concentration gradient. On the other hand, the O3 burden, averaged over all newly urbanized grid cells, consistently increases from the surface to a height of about 4 km. Sensitivity tests show that the responses of pollutant concentrations to the spatial extent of urbanization are nearly linear near the surface, but nonlinear at higher altitudes. Over eastern China, each 10 % increase in nearby urban land coverage on average leads to a decrease of approximately 2 % in surface concentrations for CO, EC, and PM2.5, while for O3 an increase of about 1 % is simulated. At 800 hPa, pollutants' concentrations tend to increase even more rapidly with an increase in nearby urban land coverage. This indicates that as large tracts of new urban land emerge, the influence of urban expansion on meteorology and air pollution would be significantly amplified. IPR analysis reveals the contribution of individual atmospheric processes to pollutants' concentration changes. It indicates that, for primary pollutants, the enhanced sink (source) caused by turbulent mixing and vertical advection in the lower (upper) atmosphere could be a key factor in changes to simulated vertical profiles. The evolution of secondary pollutants is further influenced by the upward relocation of precursors that impact gas-phase chemistry for O3 and aerosol processes for PM2.5. Our study indicates that dense urbanization has a moderate dilution effect on surface primary airborne contaminants, but may intensify severe haze and ozone pollution if local emissions are not well controlled.

scholarly journals Air pollutant emissions from Chinese households: A major and underappreciated ambient pollution source

2016 ◽  
Vol 113 (28) ◽  
pp. 7756-7761 ◽  
Author(s):  
Jun Liu ◽  
Denise L. Mauzerall ◽  
Qi Chen ◽  
Qiang Zhang ◽  
Yu Song ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Eastern China ◽  
Pollution Prevention ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Base Case ◽  
Chinese Government ◽  
Industrial Sectors ◽  
Bth Region

As part of the 12th Five-Year Plan, the Chinese government has developed air pollution prevention and control plans for key regions with a focus on the power, transport, and industrial sectors. Here, we investigate the contribution of residential emissions to regional air pollution in highly polluted eastern China during the heating season, and find that dramatic improvements in air quality would also result from reduction in residential emissions. We use the Weather Research and Forecasting model coupled with Chemistry to evaluate potential residential emission controls in Beijing and in the Beijing, Tianjin, and Hebei (BTH) region. In January and February 2010, relative to the base case, eliminating residential emissions in Beijing reduced daily average surface PM2.5 (particulate mater with aerodynamic diameter equal or smaller than 2.5 micrometer) concentrations by 14 ± 7 μg⋅m−3 (22 ± 6% of a baseline concentration of 67 ± 41 μg⋅m−3; mean ± SD). Eliminating residential emissions in the BTH region reduced concentrations by 28 ± 19 μg⋅m−3 (40 ± 9% of 67 ± 41 μg⋅m−3), 44 ± 27 μg⋅m−3 (43 ± 10% of 99 ± 54 μg⋅m−3), and 25 ± 14 μg⋅m−3 (35 ± 8% of 70 ± 35 μg⋅m−3) in Beijing, Tianjin, and Hebei provinces, respectively. Annually, elimination of residential sources in the BTH region reduced emissions of primary PM2.5 by 32%, compared with 5%, 6%, and 58% achieved by eliminating emissions from the transportation, power, and industry sectors, respectively. We also find air quality in Beijing would benefit substantially from reductions in residential emissions from regional controls in Tianjin and Hebei, indicating the value of policies at the regional level.

scholarly journals Study on mapping ozone pollution and ozone pollution regime in Cantho city then propose solutions to reduce ozone pollution

2018 ◽  
Vol 1 (6) ◽  
pp. 247-257
Author(s):  
Bang Quoc Ho ◽  
Tam Thoai Nguyen ◽  
Khue Hoang Ngoc Vu
Keyword(s):  
Air Pollution ◽  
Ozone Concentration ◽  
Ambient Air ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Ozone Pollution ◽  
Sensitive Areas ◽  
Study Results ◽  
Can Tho City ◽  
The City

Can Tho City is one the 5th largest city in Vietnam, with hight rate of economic growth and densely populated with 1,251,809 people, butsling traffic activities with 566,593 motobikes and 15,105 cars and hundreds of factories. The air in Can Tho city is polluted by dust and ozone. However, Can Tho city currently does not have a study on the simulation air pollution spread, therefore we do not have an overview on the status of air pollution in order to do not have solutions to limit the increase of pollution status of the city. The purpose of this study is to collect air pollutant emissions from other study. After that, TAPOM model is used to simulate the effects of ozone on the surrounding areas and study the ozone regime in Cantho city. The study results showed that the highest ozone concentration for an hour everage is 196 μg/m3. Compare with national technical regulation about ambient air QCVN 5:2013/BTNMT, ozone concentration is approximately at the allowable limit. The study of ozone regime had identified that VOC sensitive areas are Ninh Kieu district and a part in the south of Binh Thuy district, and NOx sensitive areas are the rested areas of Cantho city. The main cause contributing to increased VOC emission in the central area of the city is motorcycles, NOx emissions in the remaining areas of Cantho city are from the rice production factories. Proposals to protect the air quality in Cantho city are suggested.

scholarly journals A review on Assessment of Air Pollution due to Vehicular Emission in Traffic Area

2018 ◽  
Vol 8 (02) ◽  
Author(s):  
Aneri A. Desai
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Ambient Air ◽  
Pollution Monitoring ◽  
Motor Vehicles ◽  
Monitoring And Control ◽  
Ambient Air Quality ◽  
Vehicular Emission ◽  
Rapid Urbanization ◽  
Air Pollution Monitoring

In Indian metropolitan cities, the extensive growth of the motor vehicles has resulted in the deterioration of environmental quality and human health. The concentrations of pollutants at major traffic areas are exceeding the permissible limits. Public are facing severe respiratory diseases and other deadly cardio-vascular diseases In India. Immediate needs for vehicular air pollution monitoring and control strategies for urban cities are necessary. Vehicular emission is the main source of deteriorating the ambient air quality of major Indian cities due to rapid urbanization. Total vehicular population is increased to 15 Lacks as per recorded data of Regional Transport Organization (RTO) till 2014-2015. This study is focused on the assessment of major air pollution parameters responsible for the air pollution due to vehicular emission. The major air pollutants responsible for air pollution due to vehicular emissions are PM10, PM2.5, Sox, Nox, HC, CO2 and CO and Other meterological parameters like Ambient temperature, Humidity, Wind direction and Wind Speed. Sampling and analysis of parameters is carried out according to National Ambient Air Quality Standards Guidelines (NAAQS) (2009) and IS 5128.

scholarly journals EURODELTA-Trends, a multi-model experiment of air quality hindcast in Europe over 1990–2010

2017 ◽  
Vol 10 (9) ◽  
pp. 3255-3276 ◽  
Author(s):  
Augustin Colette ◽  
Camilla Andersson ◽  
Astrid Manders ◽  
Kathleen Mar ◽  
Mihaela Mircea ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Boundary Conditions ◽  
Radiative Forcing ◽  
Regional Scale ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Mitigation Measures ◽  
Modelling Experiment ◽  
Technical Features

Abstract. The EURODELTA-Trends multi-model chemistry-transport experiment has been designed to facilitate a better understanding of the evolution of air pollution and its drivers for the period 1990–2010 in Europe. The main objective of the experiment is to assess the efficiency of air pollutant emissions mitigation measures in improving regional-scale air quality. The present paper formulates the main scientific questions and policy issues being addressed by the EURODELTA-Trends modelling experiment with an emphasis on how the design and technical features of the modelling experiment answer these questions. The experiment is designed in three tiers, with increasing degrees of computational demand in order to facilitate the participation of as many modelling teams as possible. The basic experiment consists of simulations for the years 1990, 2000, and 2010. Sensitivity analysis for the same three years using various combinations of (i) anthropogenic emissions, (ii) chemical boundary conditions, and (iii) meteorology complements it. The most demanding tier consists of two complete time series from 1990 to 2010, simulated using either time-varying emissions for corresponding years or constant emissions. Eight chemistry-transport models have contributed with calculation results to at least one experiment tier, and five models have – to date – completed the full set of simulations (and 21-year trend calculations have been performed by four models). The modelling results are publicly available for further use by the scientific community. The main expected outcomes are (i) an evaluation of the models' performances for the three reference years, (ii) an evaluation of the skill of the models in capturing observed air pollution trends for the 1990–2010 time period, (iii) attribution analyses of the respective role of driving factors (e.g. emissions, boundary conditions, meteorology), (iv) a dataset based on a multi-model approach, to provide more robust model results for use in impact studies related to human health, ecosystem, and radiative forcing.

scholarly journals A Model-Based Analysis of Spatio-Temporal Changes of the Urban Expansion in Arid Area of Western China: A Case Study in North Xinjiang Economic Zone

Atmosphere ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 989
Author(s):  
Jing Qian ◽  
Qiming Zhou ◽  
Xi Chen ◽  
Bo Sun
Keyword(s):  
Land Use ◽  
Driving Forces ◽  
Urban Expansion ◽  
Eastern China ◽  
Western China ◽  
Urbanization Process ◽  
Rapid Urbanization ◽  
North Xinjiang ◽  
Economic Zone ◽  
S Model

Investigation of urban expansion can provide a better understanding of the urbanization process and its driving forces, which is critical for environmental management and land use planning. Total of 514 sampling points from the aerial photos and field sampling were applied to assess the image accuracy. A Conversion of Land Use and its Effect at Small Region Extent (CLUE-S) model was established to simulate the urbanization process at the township level in the North Xinjiang Economic Zone (NXEZ) of western China. Historical land use and land cover changes with multi-temporal remote sensing data were retrieved, and the underlying driving forces were explored by training the CLUE-S model. Moreover, future changes in urban development were simulated under different scenarios. Results showed that the overall accuracy reaches larger than 80% for the years of 2002, 2005, and 2007, and the corresponding kappa coefficient is bigger than 0.8. The NXEZ is at a premature development stage compared with urban clusters in eastern China. Before 1999, the driving force in this region was primary industry development. In recent years, secondary industries started to show significance in urbanization. These findings indicate that the industrial base and economic development in the NXEZ are still relatively weak and have not taken a strong leading role. When industry and population become the main driving factors, the regional economy will enter a new stage of leap-forward development, which in turn will stimulate a new round of rapid urbanization.

scholarly journals Scenario Analysis on Climate Change Impacts of Urban Land Expansion under Different Urbanization Patterns: A Case Study of Wuhan Metropolitan

2013 ◽  
Vol 2013 ◽  
pp. 1-12 ◽  
Author(s):  
Xinli Ke ◽  
Feng Wu ◽  
Caixue Ma
Keyword(s):  
Climate Change ◽  
Land Use ◽  
Urban Expansion ◽  
Regional Climate ◽  
Urban Land ◽  
Urban Land Use ◽  
Rapid Urbanization ◽  
Urban Land Expansion ◽  
The Impact

Urban land expansion plays an important role in climate change. It is significant to select a reasonable urban expansion pattern to mitigate the impact of urban land expansion on the regional climate in the rapid urbanization process. In this paper, taking Wuhan metropolitan as the case study area, and three urbanization patterns scenarios are designed to simulate spatial patterns of urban land expansion in the future using the Partitioned and Asynchronous Cellular Automata Model. Then, simulation results of land use are adjusted and inputted into WRF (Weather Research and Forecast) model to simulate regional climate change. The results show that: (1) warming effect is strongest under centralized urbanization while it is on the opposite under decentralized scenario; (2) the warming effect is stronger and wider in centralized urbanization scenario than in decentralized urbanization scenario; (3) the impact trends of urban land use expansion on precipitation are basically the same under different scenarios; (4) and spatial distribution of rainfall was more concentrated under centralized urbanization scenario, and there is a rainfall center of wider scope, greater intensity. Accordingly, it can be concluded that decentralized urbanization is a reasonable urbanization pattern to mitigate climate change in rapid urbanization period.

scholarly journals Comparison of emissions inventories of anthropogenic air pollutants and greenhouse gases in China

2017 ◽  
Vol 17 (10) ◽  
pp. 6393-6421 ◽  
Author(s):  
Eri Saikawa ◽  
Hankyul Kim ◽  
Min Zhong ◽  
Alexander Avramov ◽  
Yu Zhao ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Emission Inventory ◽  
Air Pollutant ◽  
Central China ◽  
Pollutant Emissions ◽  
Mitigation Measures ◽  
Economic Activities ◽  
Temporal And Spatial Distribution ◽  
Emissions Inventories

Abstract. Anthropogenic air pollutant emissions have been increasing rapidly in China, leading to worsening air quality. Modelers use emissions inventories to represent the temporal and spatial distribution of these emissions needed to estimate their impacts on regional and global air quality. However, large uncertainties exist in emissions estimates. Thus, assessing differences in these inventories is essential for the better understanding of air pollution over China. We compare five different emissions inventories estimating emissions of carbon dioxide (CO2), carbon monoxide (CO), nitrogen oxides (NOx), sulfur dioxide (SO2), and particulate matter with an aerodynamic diameter of 10 µm or less (PM10) from China. The emissions inventories analyzed in this paper include the Regional Emission inventory in ASia v2.1 (REAS), the Multi-resolution Emission Inventory for China (MEIC), the Emission Database for Global Atmospheric Research v4.2 (EDGAR), the inventory by Yu Zhao (ZHAO), and the Greenhouse Gas and Air Pollution Interactions and Synergies (GAINS). We focus on the period between 2000 and 2008, during which Chinese economic activities more than doubled. In addition to national totals, we also analyzed emissions from four source sectors (industry, transport, power, and residential) and within seven regions in China (East, North, Northeast, Central, Southwest, Northwest, and South) and found that large disagreements exist among the five inventories at disaggregated levels. These disagreements lead to differences of 67 µg m−3, 15 ppbv, and 470 ppbv for monthly mean PM10, O3, and CO, respectively, in modeled regional concentrations in China. We also find that all the inventory emissions estimates create a volatile organic compound (VOC)-limited environment and MEIC emissions lead to much lower O3 mixing ratio in East and Central China compared to the simulations using REAS and EDGAR estimates, due to their low VOC emissions. Our results illustrate that a better understanding of Chinese emissions at more disaggregated levels is essential for finding effective mitigation measures for reducing national and regional air pollution in China.

scholarly journals Vegetation feedbacks during drought exacerbate ozone air pollution extremes in Europe

2020 ◽  
Author(s):  
Meiyun Lin ◽  
Larry Horowitz ◽  
Yuanyu Xie ◽  
Fabien Paulot ◽  
Sergey Malyshev ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Drought Stress ◽  
Dry Deposition ◽  
Surface Ozone ◽  
Ozone Pollution ◽  
Ozone Uptake ◽  
Vegetation Feedbacks ◽  
Ozone Episodes ◽  
Pollution Episodes

<p>This study highlights a previously under-appreciated “climate penalty” feedback mechanism - namely, substantial reductions of ozone uptake by water stressed vegetation – as a missing piece to the puzzle of why European ozone pollution episodes have not decreased as expected in recent decades, despite marked reductions in regional emissions of ozone precursors due to regulatory changes. The most extreme ozone pollution episodes are linked to heatwaves and droughts, which are increasing in frequency and intensity over Europe, with severe impacts on natural and human systems. Under drought stress, plants close their stomata to reduce water loss, consequently limiting the ozone uptake by vegetation (a component of dry deposition), leading to increased surface ozone concentrations. Such land-biosphere feedbacks are often overlooked in prior air quality projections, owing to a lack of process-based model formulations. Here, we use six decades of observations and Earth system model simulations (1960-2018) with an interactive dry deposition scheme to show that declining ozone removal by water-stressed vegetation in the warming climate exacerbate ozone air pollution over Europe. Incorporated into a dynamic vegetation land – atmospheric chemistry – climate model, the dry deposition scheme mechanistically describes the response of ozone deposition to atmospheric CO<sub>2 </sub>concentration, canopy air vapor pressure deficit, and soil water availability. Our observational and modeling analyses reveal drought stress causing as much as 70% reductions in ozone removal by forests. Reduced ozone removal by water-stressed vegetation worsens peak ozone episodes during European mega-droughts, such as the 2003 event, offsetting much of the air quality improvements gained from regional emission controls. Accounting for vegetation feedbacks leads to a three-fold increase in high surface ozone events above 80 ppbv (8-hour average) and a 20% increase in the sensitivity of ozone pollution extremes (95<sup>th </sup>percentile) to increasing temperature. As the frequency of hot and dry summers is expected to increase in the coming decades, this ozone climate penalty could be severe and therefore needs to be considered when designing clean air policy in the European Union. </p><p>Notes: This study is currently under review for possible publication in Nature Climate Change. </p>

scholarly journals Mapping the drivers of formaldehyde (HCHO) variability from 2015–2019 over eastern China: insights from FTIR observation and GEOS-Chem model simulation

2020 ◽  
Author(s):  
Youwen Sun ◽  
Hao Yin ◽  
Cheng Liu ◽  
Lin Zhang ◽  
Yuan Cheng ◽  
...  
Keyword(s):  
Air Quality ◽  
Model Simulation ◽  
Eastern China ◽  
Mean Value ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Mitigation Measures ◽  
Positive Trend ◽  
Oh Radical ◽  
Clean Air

Abstract. The major air pollutant emissions have decreased and the overall air quality has substantially improved across China in recent years as a consequence of active clean air policies for mitigating severe air pollution problems. As key precursors of formaldehyde (HCHO) and ozone (O3), the volatile organic compounds (VOCs) in China are still increasing because current clean air policies lack mitigation measures for VOCs. In this study, we mapped the drivers of HCHO variability over eastern China using ground-based high-resolution Fourier transform infrared (FTIR) spectrometry and GEOS-Chem model simulation. Diurnal, seasonal, and interannual variability of HCHO over eastern China was investigated and hydroxyl (OH) radical production from HCHO was evaluated. The relative contributions of emitted and photochemical sources to the observed HCHO were analysed by using ground level carbon monoxide (CO) and Ox (O3 + nitrogen oxide (NO2)) as tracers for emitted and photochemical HCHO, respectively. Contributions of various emission sectors and geographical transport to the observed HCHO summertime enhancements were determined by using a GEOS-Chem tagged-tracer simulation. The tropospheric HCHO volume mixing ratio (VMR) reached a maximum monthly mean value of (1.1 ± 0.27) ppbv in July and a minimum monthly mean value of (0.4 ± 0.11) ppbv in January. The tropospheric HCHO VMR time series from 2015–2019 shows a positive trend of (1.43 ± 0.14) % per yr. The photochemical HCHO is the dominant source of atmospheric HCHO over eastern China for most of the year (68.1 %). In the studied years, the HCHO photolysis was an important source of OH radical over eastern China during all sunlight hours of both summer and winter days. The anthropogenic emissions (fossil fuel + biofuel emissions) accounted for 31.96 % and the natural emissions (biomass burning + biogenic) accounted for 48.75 % of HCHO summertime enhancements. The observed HCHO summertime enhancements were largely attributed to the emissions within China (76.92 %), where eastern China dominated the contribution (46.24 %). The increased trend in HCHO in recent years was largely attributed to the increase in the HCHO precursors such as CH4 and nonmethane VOCs (NMVOCs). This study can provide an evaluation of recent VOC emissions and regional photochemical capacity in China. In addition, this study is also important for regulatory and control purposes and will help to improve urban air quality and contribute to the formation of new Chinese clean air policies in the future.

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