scholarly journals Effects of Urbanization on the Temperature Inversion Breakup in a Mountain Valley with Implications for Air Quality

2014 ◽  
Vol 53 (4) ◽  
pp. 840-858 ◽  
Author(s):  
Angela M. Rendón ◽  
Juan F. Salazar ◽  
Carlos A. Palacio ◽  
Volkmar Wirth ◽  
Björn Brötz
Keyword(s):  
Air Quality ◽  
Urban Heat Island ◽  
Temperature Inversion ◽  
Effect Of Temperature ◽  
Heat Island ◽  
Valley Wind ◽  
Convective Boundary ◽  
Mountain Valley ◽  
Urban Heat ◽  
Temperature Inversions

AbstractMany cities located in valleys with limited ventilation experience serious air pollution problems. The ventilation of an urban valley can be limited not only by orographic barriers, but also by urban heat island–induced circulations and/or the capping effect of temperature inversions. Furthermore, land-use/-cover changes caused by urbanization alter the dynamics of temperature inversions and urban heat islands, thereby affecting air quality in an urban valley. By means of idealized numerical simulations, it is shown that in a mountain valley subject to temperature inversions urbanization can have an important influence on air quality through effects on the inversion breakup. Depending on the urban area fraction in the simulations, the breakup time changes, the cross-valley wind system can evolve from a confined to an open system during the daytime, the slope winds can be reversed by the interplay between the urban heat island and the temperature inversion, and the breakup pattern can migrate from one dominated by the growth of the convective boundary layer to one also involving the removal of mass from the valley floor by the upslope winds. The analysis suggests that the influence of urbanization on the air quality of an urban valley may lead to contrasting and possibly counterintuitive effects when considering temperature inversions. More urban land does not necessarily imply worse air quality, even when considering that the amount of pollutants emitted grows with increased urbanization.

The impact of COVID-19 lockdowns on surface urban heat island changes and air-quality improvements across 21 major cities in the Middle East

2021 ◽  
pp. 117802
Author(s):  
Ahmed M. El Kenawy ◽  
Juan I. Lopez-Moreno ◽  
Matthew F. McCabe ◽  
Fernando Domínguez-Castro ◽  
Dhais Peña-Angulo ◽  
...  
Keyword(s):  
Air Quality ◽  
Middle East ◽  
Urban Heat Island ◽  
Heat Island ◽  
Quality Improvements ◽  
Urban Heat ◽  
Surface Urban Heat Island ◽  
The Impact

Trade-off between urban heat island mitigation and air quality in urban valleys

Urban Climate ◽  
2020 ◽  
Vol 31 ◽  
pp. 100542 ◽  
Author(s):  
Juan J. Henao ◽  
Angela M. Rendón ◽  
Juan F. Salazar
Keyword(s):  
Air Quality ◽  
Urban Heat Island ◽  
Heat Island ◽  
Trade Off ◽  
Urban Heat

scholarly journals Secondary effects of urban heat island mitigation measures on air quality

2016 ◽  
Vol 125 ◽  
pp. 199-211 ◽  
Author(s):  
Joachim Fallmann ◽  
Renate Forkel ◽  
Stefan Emeis
Keyword(s):  
Air Quality ◽  
Urban Heat Island ◽  
Mitigation Measures ◽  
Heat Island ◽  
Secondary Effects ◽  
Urban Heat

Effect of Temperature Adjustments on the Minneapolis-St. Paul Urban Heat Island

1981 ◽  
Vol 20 (11) ◽  
pp. 1295-1300 ◽  
Author(s):  
Julie A. Winkler ◽  
Richard H. Skaggs ◽  
Donald G. Baker
Keyword(s):  
Urban Heat Island ◽  
Effect Of Temperature ◽  
Heat Island ◽  
Urban Heat

scholarly journals Earth Observations Informing Cities’ Operations and Planning

Eos ◽  
2020 ◽  
Vol 101 ◽  
Author(s):  
Margaret Hurwitz ◽  
Christian Braneon ◽  
Dalia Kirschbaum ◽  
Felipe Mandarino ◽  
Raed Mansour
Keyword(s):  
Air Quality ◽  
Urban Heat Island ◽  
Rio De Janeiro ◽  
Heat Island ◽  
Earth Observations ◽  
Urban Heat

Rio de Janeiro, Brazil, and Chicago, Ill., are using NASA Earth observations to map, monitor, and forecast water and air quality, urban heat island effects, landslide risks, and more.

scholarly journals Street-scale air quality modelling for Beijing during a winter 2016 measurement campaign

2020 ◽  
Vol 20 (5) ◽  
pp. 2755-2780 ◽  
Author(s):  
Michael Biggart ◽  
Jenny Stocker ◽  
Ruth M. Doherty ◽  
Oliver Wild ◽  
Michael Hollaway ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Urban Heat Island ◽  
Monitoring Network ◽  
Ambient Air ◽  
Traffic Emissions ◽  
Heat Island ◽  
Emissions Inventory ◽  
Measurement Campaign ◽  
Urban Heat

Abstract. We examine the street-scale variation of NOx, NO2, O3 and PM2.5 concentrations in Beijing during the Atmospheric Pollution and Human Health in a Chinese Megacity (APHH-China) winter measurement campaign in November–December 2016. Simulations are performed using the urban air pollution dispersion and chemistry model ADMS-Urban and an explicit network of road source emissions. Two versions of the gridded Multi-resolution Emission Inventory for China (MEIC v1.3) are used: the standard MEIC v1.3 emissions and an optimised version, both at 3 km resolution. We construct a new traffic emissions inventory by apportioning the transport sector onto a detailed spatial road map. Agreement between mean simulated and measured pollutant concentrations from Beijing's air quality monitoring network and the Institute of Atmospheric Physics (IAP) field site is improved when using the optimised emissions inventory. The inclusion of fast NOx–O3 chemistry and explicit traffic emissions enables the sharp concentration gradients adjacent to major roads to be resolved with the model. However, NO2 concentrations are overestimated close to roads, likely due to the assumption of uniform traffic activity across the study domain. Differences between measured and simulated diurnal NO2 cycles suggest that an additional evening NOx emission source, likely related to heavy-duty diesel trucks, is not fully accounted for in the emissions inventory. Overestimates in simulated early evening NO2 are reduced by delaying the formation of stable boundary layer conditions in the model to replicate Beijing's urban heat island. The simulated campaign period mean PM2.5 concentration range across the monitoring network (∼15 µg m−3) is much lower than the measured range (∼40 µg m−3). This is likely a consequence of insufficient PM2.5 emissions and spatial variability, neglect of explicit point sources, and assumption of a homogeneous background PM2.5 level. Sensitivity studies highlight that the use of explicit road source emissions, modified diurnal emission profiles, and inclusion of urban heat island effects permit closer agreement between simulated and measured NO2 concentrations. This work lays the foundations for future studies of human exposure to ambient air pollution across complex urban areas, with the APHH-China campaign measurements providing a valuable means of evaluating the impact of key processes on street-scale air quality.

scholarly journals Temperature Inversion Breakup with Impacts on Air Quality in Urban Valleys Influenced by Topographic Shading

2015 ◽  
Vol 54 (2) ◽  
pp. 302-321 ◽  
Author(s):  
Angela M. Rendón ◽  
Juan F. Salazar ◽  
Carlos A. Palacio ◽  
Volkmar Wirth
Keyword(s):  
Air Pollution ◽  
Urban Heat Island ◽  
Urban Areas ◽  
Inversion Layer ◽  
Temperature Inversion ◽  
Topographic Effects ◽  
Heat Island ◽  
Pollution Transport ◽  
High Emission ◽  
Urban Heat

AbstractUrban valleys can experience serious air pollution problems as a combined result of their limited ventilation and the high emission of pollutants from the urban areas. Idealized simulations were analyzed to elucidate the breakup of an inversion layer in urban valleys subject to a strong low-level temperature inversion and topographic effects on surface heating such as topographic shading, as well as the associated air pollution transport mechanisms. The results indicate that the presence and evolution in time of the inversion layer and its interplay with an urban heat island within the valley strongly influence the venting of pollutants out of urban valleys. Three mechanisms of air pollution transport were identified. These are transport by upslope winds, transport by an urban heat island–induced circulation, and transport within a closed slope-flow circulation below an inversion layer.

Evidence of the effect of an urban heat island on air quality near a landfill

Urban Climate ◽  
2014 ◽  
Vol 10 ◽  
pp. 745-757 ◽  
Author(s):  
T. Plocoste ◽  
S. Jacoby-Koaly ◽  
J. Molinié ◽  
R.H. Petit
Keyword(s):  
Air Quality ◽  
Urban Heat Island ◽  
Heat Island ◽  
Urban Heat
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