scholarly journals Changes in regional meteorology induced by anthropogenic heat and their impacts on air quality in South China

2016 ◽  
Vol 16 (23) ◽  
pp. 15011-15031 ◽  
Author(s):  
Min Xie ◽  
Kuanguang Zhu ◽  
Tijian Wang ◽  
Wen Feng ◽  
Da Gao ◽  
...  
Keyword(s):  
Air Quality ◽  
Wind Speed ◽  
South China ◽  
Urban Areas ◽  
Air Pollutants ◽  
Surface Wind ◽  
Vertical Movement ◽  
Anthropogenic Heat ◽  
Big Cities ◽  
The Impact

Abstract. Anthropogenic heat (AH) emissions from human activities can change the urban circulation and thereby affect the air pollution in and around cities. Based on statistic data, the spatial distribution of AH flux in South China is estimated. With the aid of the Weather Research and Forecasting model coupled with Chemistry (WRF/Chem), in which the AH parameterization is developed to incorporate the gridded AH emissions with temporal variation, simulations for January and July in 2014 are performed over South China. By analyzing the differences between the simulations with and without adding AH, the impact of AH on regional meteorology and air quality is quantified. The results show that the regional annual mean AH fluxes over South China are only 0.87 W m−2, but the values for the urban areas of the Pearl River Delta (PRD) region can be close to 60 W m−2. These AH emissions can significantly change the urban heat island and urban-breeze circulations in big cities. In the PRD city cluster, 2 m air temperature rises by 1.1° in January and over 0.5° in July, the planetary boundary layer height (PBLH) increases by 120 m in January and 90 m in July, 10 m wind speed is intensified to over 0.35 m s−1 in January and 0.3 m s−1 in July, and accumulative precipitation is enhanced by 20–40 % in July. These changes in meteorological conditions can significantly impact the spatial and vertical distributions of air pollutants. Due to the increases in PBLH, surface wind speed and upward vertical movement, the concentrations of primary air pollutants decrease near the surface and increase in the upper levels. But the vertical changes in O3 concentrations show the different patterns in different seasons. The surface O3 concentrations in big cities increase with maximum values of over 2.5 ppb in January, while O3 is reduced at the lower layers and increases at the upper layers above some megacities in July. This phenomenon can be attributed to the fact that chemical effects can play a significant role in O3 changes over South China in winter, while the vertical movement can be the dominant effect in some big cities in summer. Adding the gridded AH emissions can better describe the heterogeneous impacts of AH on regional meteorology and air quality, suggesting that more studies on AH should be carried out in climate and air quality assessments.

scholarly journals Changes of regional meteorology induced by anthropogenic heat and their impacts on air quality in South China

2016 ◽  
Author(s):  
Min Xie ◽  
Kuanguang Zhu ◽  
Tijian Wang ◽  
Wen Feng ◽  
Minggao Li ◽  
...  
Keyword(s):  
Air Quality ◽  
Wind Speed ◽  
South China ◽  
Air Pollutants ◽  
Surface Wind ◽  
Vertical Movement ◽  
Anthropogenic Heat ◽  
Near Surface ◽  
Big Cities ◽  
The Impact

Abstract. Anthropogenic heat (AH) emissions from human activities can change the urban circulation and thereby affect the air pollution in and around cities. Based on statistic data, the spatial distribution of AH flux in South China is estimated. With the aid of the WRF/Chem model in which the AH parameterization is developed to incorporate the gridded AH emissions with temporal variation, the simulations for January and July in 2014 are performed over South China. By analyzing the differences between the simulations with and without adding AH, the impact of AH on regional meteorology and air quality are quantified. The results show that the regional annual mean AH fluxes over South China are only 0.87 W/m2, but the values for the urban areas of the Pearl River Delta (PRD) region can be close to 60 W/m2. These AH emissions can significantly change the urban heat island and urban-breeze circulations in the big cities. In the PRD city cluster, 2-m air temperature rises up by 1.1 ℃ in January and over 0.5 ℃ in July, the boundary layer height increases by 120 m in January and 90 m in July, 10-m wind speed is intensified over 0.35 m/s in January and 0.3 m/s in July, and the accumulative precipitation is enhanced by 20–40 % in July. These changes of meteorological conditions can significantly impact the spatial and vertical distributions of air pollutants. Due to the increases of PBLH, surface wind speed and upward vertical movement, the concentrations of primary air pollutants decrease near surface and increase at the upper levels. But the vertical changes of O3 concentrations show the different patterns in different seasons. The surface O3 concentrations in big cities increase with maximum values over 2.5 ppb in January, while O3 is reduced at the lower layers and increases at the upper layers above some megacities in July. This phenomenon should be attributed to the facts that the chemical effects can play a significant role in O3 changes over South China in winter, while the vertical movement can be the dominant effect in some big cities in summer. Adding the gridded AH emissions can better describe the heterogeneous impacts of AH on regional meteorology and air quality, suggesting that more studies on AH should be carried out in the climate and air quality assessments.

scholarly journals Modeling of the anthropogenic heat flux and its effect on regional meteorology and air quality over the Yangtze River Delta region, China

2016 ◽  
Vol 16 (10) ◽  
pp. 6071-6089 ◽  
Author(s):  
Min Xie ◽  
Jingbiao Liao ◽  
Tijian Wang ◽  
Kuanguang Zhu ◽  
Bingliang Zhuang ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
Vertical Movement ◽  
Anthropogenic Heat ◽  
The Yangtze River ◽  
The Yrd ◽  
Surface O3 ◽  
The Yangtze River Delta

Abstract. Anthropogenic heat (AH) emissions from human activities caused by urbanization can affect the city environment. Based on the energy consumption and the gridded demographic data, the spatial distribution of AH emission over the Yangtze River Delta (YRD) region is estimated. Meanwhile, a new method for the AH parameterization is developed in the WRF/Chem model, which incorporates the gridded AH emission data with the seasonal and diurnal variations into the simulations. By running this upgraded WRF/Chem for 2 typical months in 2010, the impacts of AH on the meteorology and air quality over the YRD region are studied. The results show that the AH fluxes over the YRD have been growing in recent decades. In 2010, the annual-mean values of AH over Shanghai, Jiangsu and Zhejiang are 14.46, 2.61 and 1.63 W m−2, respectively, with the high value of 113.5 W m−2 occurring in the urban areas of Shanghai. These AH emissions can significantly change the urban heat island and urban-breeze circulations in the cities of the YRD region. In Shanghai, 2 m air temperature increases by 1.6 °C in January and 1.4 °C in July, the PBLH (planetary boundary layer height) rises up by 140 m in January and 160 m in July, and 10 m wind speed is enhanced by 0.7 m s−1 in January and 0.5 m s−1 in July, with a higher increment at night. The enhanced vertical movement can transport more moisture to higher levels, which causes the decrease in water vapor at ground level and the increase in the upper PBL (planetary boundary layer), and thereby induces the accumulative precipitation to increase by 15–30 % over the megacities in July. The adding of AH can impact the spatial and vertical distributions of the simulated pollutants as well. The concentrations of primary air pollutants decrease near the surface and increase at the upper levels, due mainly to the increases in PBLH, surface wind speed and upward air vertical movement. But surface O3 concentrations increase in the urban areas, with maximum changes of 2.5 ppb in January and 4 ppb in July. Chemical direct (the rising up of air temperature directly accelerates surface O3 formation) and indirect (the decrease in NOx at the ground results in the increase in surface O3) effects can play a significant role in O3 changes over this region. The meteorology and air pollution predictions in and around large urban areas are highly sensitive to the anthropogenic heat inputs, suggesting that AH should be considered in the climate and air quality assessments.

The effects of anthropogenic heat fluxes on regional meteorology and air quality in typical city clusters of China

2020 ◽  
Author(s):  
Min Xie ◽  
Tijian Wang ◽  
Jie Shi ◽  
Mengmeng Li ◽  
Da Gao ◽  
...  
Keyword(s):  
Air Quality ◽  
Wind Speed ◽  
Significant Role ◽  
Air Pollutants ◽  
Heat Fluxes ◽  
Anthropogenic Heat ◽  
Atmospheric Environment ◽  
Urban Meteorology ◽  
Ozone Concentrations ◽  
Chemical Effects

<p>Anthropogenic heat (AH) can affect regional meteorology and air quality. The spatial distributions of AH fluxes in the typical city clusters of China are estimated. Moreover, in order to study their impacts on regional atmospheric environment, these heat fluxes are incorporated into the modified WRF/Chem with the seasonal and the diurnal variation. The modeling results show that AH fluxes over YRD and PRD have been growing in recent years. The high values of AH can reach 113.5 W/m<sup>2</sup> in YRD and 60 W/m<sup>2</sup> in PRD, respectively. AH fluxes can significantly change the urban meteorology. In YRD, 2-m air temperature (T<sub>2</sub>) increases by 1.6 °С in January and 1.4°С in July, the planetary boundary layer height (PBLH) rises up by 140m in January and 160m in July, and 10-m wind speed (W<sub>10</sub>) is intensified by 0.7 m/s in January and 0.5 m/s in July. More moisture can be transported to higher levels, and increase the accumulative precipitation by 15-30% in July of YRD. In PRD, T<sub>2</sub> rises up by 1.1°С in January and over 0.5°С in July, the PBLH increases by 120m in January and 90m in July, W<sub>10</sub> is enhanced over 0.35 m/s in January and 0.3 m/s in July, and the accumulative precipitation is intensified by 20-40% in July. These changes in meteorology can influence the distribution of air pollutants as well. Due to the increase of PBLH, surface wind speed and upward movement, the concentrations of primary air pollutants decrease near surface and increase at the upper layers over the cities. Chemical effects can play a significant role in ozone changes over the urban areas of YRD, so ozone concentrations increase at surface and decrease at the upper layers. In PRD cities, however, the chemical effects play a significant role in ozone changes in winter, while the vertical movement can be the dominant effect in summer. Thus, ozone concentrations in big cities increase in January, but decrease at the lower layers and increase at the upper layers in July. In all, AH fluxes should not be ignored in urban meteorology and air quality assessments.</p>

scholarly journals Modeling of the anthropogenic heat flux and its effect on air quality over the Yangtze River Delta region, China

2015 ◽  
Vol 15 (22) ◽  
pp. 32367-32412 ◽  
Author(s):  
M. Xie ◽  
J. Liao ◽  
T. Wang ◽  
K. Zhu ◽  
B. Zhuang ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Yangtze River ◽  
Yangtze River Delta ◽  
Vertical Movement ◽  
Anthropogenic Heat ◽  
The Yangtze River ◽  
The Yrd ◽  
Surface O3 ◽  
The Yangtze River Delta

Abstract. Anthropogenic heat (AH) emissions from human activities caused by urbanization can affect the city environment. Based on the energy consumption and the gridded demographic data, the spatial distribution of AH emission over the Yangtze River Delta (YRD) region is estimated. Meanwhile, a new method for the AH parameterization is developed in the WRF/Chem model, which incorporates the gridded AH emission data with the seasonal and the diurnal variations into the simulations. By running this upgraded WRF/Chem for two typical months in 2010, the impacts of AH on the meteorology and air quality over the YRD region are studied. The results show that the AH fluxes over YRD have been growing in recent decades. In 2010, the annual mean values of AH over Shanghai, Jiangsu and Zhejiang are 14.46, 2.61 and 1.63 W m−2 respectively, with the high values of 113.5 W m−2 occurring in the urban areas of Shanghai. These AH emissions can significantly change the urban heat island and urban-breeze circulations in the cities of the YRD region. In Shanghai, 2 m air temperature increases by 1.6 °C in January and 1.4 °C in July, the planetary boundary layer height rises up by 140 m in January and 160 m in July, and 10 m wind speed is enhanced by 0.7 m s−1 in January and 0.5 m s−1 in July, with higher increment at night. And the enhanced vertical movement can transport more moisture to higher levels, which causes the decrease of water vapor at the ground level and the increase in the upper PBL, and thereby induces the accumulative precipitation to increase by 15–30 % over the megacities in July. The adding AH can impact the spatial and vertical distributions of the simulated pollutants as well. The concentrations of primary air pollutants decrease near surface and increase at the upper levels, due mainly to the increases of PBLH, surface wind speed and upward air vertical movement. But surface O3 concentrations increase in the urban areas, with maximum changes of 2.5 ppb in January and 4 ppb in July. Chemical direct (the rising up of air temperature directly accelerate surface O3 formation) and indirect (the decrease in NOx at the ground results in the increase of surface O3) effects can play a significant role in O3 changes over this region. The meteorology and air pollution predictions in and around large urban areas are highly sensitive to the anthropogenic heat inputs, suggesting that AH should be considered in any climate and air quality assessment.

scholarly journals IMPACT OF URBAN LAND USES AND ACTIVITES ON THE AMBIENT AIR QUALITY IN KLANG VALLEY, MALAYSIA FROM 2014 TO 2020

2020 ◽  
Vol 18 (14) ◽  
Author(s):  
Oliver Hoon Leh Ling ◽  
Marlyana Azyyati Marzukhi ◽  
Jie Kwong Qi ◽  
Nurul Ashikin Mabahwi
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Air Pollutants ◽  
Ambient Air ◽  
Air Pollutant ◽  
Land Uses ◽  
Ambient Air Quality ◽  
Residential Areas ◽  
Klang Valley ◽  
The Impact

Ambient air in the urban area normally is more polluted than less developed areas. This is due to the concentration of urban activities, such as industrial, transportations and commercial or business activities. A study about the impact of urban land uses and activities on the levels of air pollutants in Malaysia’s most urbanised and most developed region that is Klang Valley was conducted. Data of Air Pollutant Index (API) and average concentration of selected air pollutants were used to analyse the ambient air quality of the selected five (5) cities or towns in Klang Valley. The air quality condition of the five (5) cities or towns were related to the land use distributions of the cities or towns with a purpose to understand the impact of land uses on the ambient air quality. Furthermore, the changes of ambient air quality before and after Movement Control Order (MCO) were analysed to examine the impact of human activity changes on the ambient air quality. The study found that a city or a town with more industrial and transportation land uses with fewer greens was more polluted than the area with less industrial and transportation land uses with more greens. However, this finding did not apply to all areas due to effect of winds on the distribution of air pollutants. Besides that, because of MCO, most people stayed at home with the mode of “work from home” that caused air pollutant levels in urban areas to decrease due to less urban activities. Nevertheless, there was a risk of an increase in air pollution levels in residential areas due to the concentration of activities, especially driving motor vehicles in residential areas. A recommendation is given to encourage “work from home” and reduce dependency on auto-mobile in residential areas in order to improve the air quality in urban areas.

scholarly journals Mitigating Intensity of Urban Heat Island by Better Understanding on Urban Morphology and Anthropogenic Heat Dispersion

2021 ◽  
Author(s):  
Chao Yuan ◽  
Shuojun Mei ◽  
Wenhui He ◽  
Ayu Sukma Adelia ◽  
Liqing Zhang
Keyword(s):  
Wind Speed ◽  
Urban Areas ◽  
Heat Emission ◽  
Urban Morphology ◽  
Anthropogenic Heat ◽  
Heat Island ◽  
Low Wind Speed ◽  
Urban Heat ◽  
Heat Dispersion ◽  
The Impact

<p>Anthropogenic heat is one of the key factors that causes intensive urban heat island due to its direct impact on ambient temperature in urban areas. Stagnated airflow due to closely packed tall buildings causes weak dilution and removal of anthropogenic heat. Consequently, research is critically needed to investigate the effect of urban morphology on anthropogenic heat dispersion and provide effective planning strategies to reduce UHI intensity, especially at the extreme scenario, such as with very low wind speed and high heat emission. This study provides scientific understanding and develops a GIS-based modelling tool to support decision-making in urban planning practice. We start from a computational parametric study at the neighbourhood scale to investigate the impact of urban morphology on heat dispersion. Site coverage ratio ( ), and frontal area density ( ) are two urban morphological parameters. Ten parametric cases with two heat emission scenarios are designed to study representative urban areas. Furthermore, based on the energy conservation within the urban canopy layer, we develop a semi-empirical model to estimate spatially-averaged in-canopy air temperature increment, in which the exchange velocity between the street canyon and overlying atmosphere is estimated by the Bentham and Britter model. The performance of the new model is validated by cross-comparing with CFD results from the parametric study. By applying this new model, the impact of anthropogenic heat on air temperature is mapped in residential areas of Singapore for both long-term annually averaged and short-term extreme low wind speed to improve urban climate sustainability and resilience.</p>

scholarly journals Impact of urban parameterization on high resolution air quality forecast with the GEM – AQ model

2012 ◽  
Vol 12 (4) ◽  
pp. 9517-9551
Author(s):  
J. Struzewska ◽  
J. W. Kaminski
Keyword(s):  
Air Quality ◽  
High Resolution ◽  
Wind Speed ◽  
Quality Parameters ◽  
Meteorological Conditions ◽  
Anthropogenic Heat ◽  
Air Quality Forecast ◽  
Pollutant Concentrations ◽  
The Impact ◽  
Quality Forecast

Abstract. The aim of this study is to assess the impact of urban cover on high-resolution air quality forecast simulations with the GEM-AQ model. The impact of urban area on the ambient atmosphere is non-stationary and short-term variability of meteorological conditions may result in significant changes of the observed intensity of urban heat island and pollutant concentrations. In this study we used the Town Energy Balance (TEB) parameterization to represent urban effects on modelled meteorological and air quality parameters at the final nesting level with horizontal resolution of ~5 km over Southern Poland. Three one-day cases representing different meteorological conditions were selected and the model was run with and without the TEB parameterization. Three urban cover categories were used in the TEB parameterization: mid-high buildings, sparse buildings and a mix of buildings and nature. Urban cover layers were constructed based on an area fraction of towns in a grid cell. To analyze the impact of urban parameterization on modelled meteorological and air quality parameters, anomalies in the lowest model layer for the temperature, wind speed and pollutant concentrations were calculated. Anomalies of the specific humidity fields indicate that the use of the TEB parameterization leads to a systematic reduction of moisture content in the air. Comparison with temperature and wind speed measurements taken at urban background monitoring stations shows that application of urban parameterization improves model results. For primary pollutants the impact of urban areas is most significant in regions characterized with high emissions. In most cases the anomalies of NO2 and CO concentrations are negative. This reduction is most likely caused by an enhanced vertical mixing due to elevated surface temperature and modified vertical stability. Although the outcome from this study is promising, it does not give an answer concerning the benefits of using TEB in the GEM-AQ model in an operational configuration. Additional long term evaluation would be required to better estimate the anthropogenic heat flux and to assess the urban impact in longer time scales (seasonal and annual average).

scholarly journals The Impact of High-Rise Buildings on the Living Environment

2018 ◽  
Vol 33 ◽  
pp. 01045 ◽  
Author(s):  
Botir Giyasov ◽  
Irina Giyasova
Keyword(s):  
Wind Speed ◽  
Urban Areas ◽  
Residential Buildings ◽  
Living Environment ◽  
Building Construction ◽  
Functional Requirements ◽  
High Rise ◽  
High Rise Building ◽  
Big Cities ◽  
The Impact

Urbanization as a socio-economic process manifested in the concentration of the population in modern big cities contributes to the development of high-rise building construction. With the development of education and culture, changing leisure habits, city residents put forward new architectural and functional requirements to the living environment and urban infrastructure. This calls for the creation of new types and forms of residential buildings, the structure of the city and transport networks. In addition, the need to develop high-rise building construction is justified by the growing demand for residential, public and administrative buildings and the lack of free space.The paper analyzes the development of high-rise building construction in urban areas. The problem of the impact of high-rise building construction in big cities on the living environment is considered. Using analytical methods, causes and sources of pollution, such as transport and engineering infrastructure have been identified. In some urban areas, there are zones with modified thermal conditions and air exchange resulting in the formation of the “urban heat island”The qualitative and quantitative characteristics of variations in temperature and wind speed with respect to the height of the building have been calculated, using the example of the Evolution Tower of the Moscow International Business Center (“Moscow City”). Calculation and comparative analysis for the cities of Moscow, Khanty-Mansiysk and Vladivostok has made it possible to assess the variation in temperature and wind speed and their impact on the living environment under different climatic conditions.

scholarly journals Modelling the impact of megacities on local, regional and global tropospheric ozone and the deposition of nitrogen species

2013 ◽  
Vol 13 (24) ◽  
pp. 12215-12231 ◽  
Author(s):  
Z. S. Stock ◽  
M. R. Russo ◽  
T. M. Butler ◽  
A. T. Archibald ◽  
M. G. Lawrence ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Climate Model ◽  
Surface Ozone ◽  
Global Scale ◽  
Chemical Environment ◽  
Ozone Production ◽  
The Uk ◽  
The Impact ◽  
Local Emissions

Abstract. We examine the effects of ozone precursor emissions from megacities on present-day air quality using the global chemistry–climate model UM-UKCA (UK Met Office Unified Model coupled to the UK Chemistry and Aerosols model). The sensitivity of megacity and regional ozone to local emissions, both from within the megacity and from surrounding regions, is important for determining air quality across many scales, which in turn is key for reducing human exposure to high levels of pollutants. We use two methods, perturbation and tagging, to quantify the impact of megacity emissions on global ozone. We also completely redistribute the anthropogenic emissions from megacities, to compare changes in local air quality going from centralised, densely populated megacities to decentralised, lower density urban areas. Focus is placed not only on how changes to megacity emissions affect regional and global NOx and O3, but also on changes to NOy deposition and to local chemical environments which are perturbed by the emission changes. The perturbation and tagging methods show broadly similar megacity impacts on total ozone, with the perturbation method underestimating the contribution partially because it perturbs the background chemical environment. The total redistribution of megacity emissions locally shifts the chemical environment towards more NOx-limited conditions in the megacities, which is more conducive to ozone production, and monthly mean surface ozone is found to increase up to 30% in megacities, depending on latitude and season. However, the displacement of emissions has little effect on the global annual ozone burden (0.12% change). Globally, megacity emissions are shown to contribute ~3% of total NOy deposition. The changes in O3, NOx and NOy deposition described here are useful for quantifying megacity impacts and for understanding the sensitivity of megacity regions to local emissions. The small global effects of the 100% redistribution carried out in this study suggest that the distribution of emissions on the local scale is unlikely to have large implications for chemistry–climate processes on the global scale.

scholarly journals Contribution of Local and Transboundary Air Pollution to the Urban Air Quality of Fukuoka, Japan

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 431
Author(s):  
Ayako Yoshino ◽  
Akinori Takami ◽  
Keiichiro Hara ◽  
Chiharu Nishita-Hara ◽  
Masahiko Hayashi ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Urban Areas ◽  
Air Pollutants ◽  
Regional Scale ◽  
Gaseous Species ◽  
Transboundary Air Pollution ◽  
Local Air Pollution ◽  
The City

Transboundary air pollution (TAP) and local air pollution (LAP) influence the air quality of urban areas. Fukuoka, located on the west side of Japan and affected by TAP from the Asian continent, is a unique example for understanding the contribution of LAP and TAP. Gaseous species and particulate matter (PM) were measured for approximately three weeks in Fukuoka in the winter of 2018. We classified two distinctive periods, LAP and TAP, based on wind speed. The classification was supported by variations in the concentration of gaseous species and by backward trajectories. Most air pollutants, including NOx and PM, were high in the LAP period and low in the TAP period. However, ozone was the exception. Therefore, our findings suggest that reducing local emissions is necessary. Ozone was higher in the TAP period, and the variation in ozone concentration was relatively small, indicating that ozone was produced outside of the city and transported to Fukuoka. Thus, air pollutants must also be reduced at a regional scale, including in China.

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