scholarly journals Modeling the impact of COVID-19 on air quality in southern California: implications for future control policies

2021 ◽  
Vol 21 (11) ◽  
pp. 8693-8708
Author(s):  
Zhe Jiang ◽  
Hongrong Shi ◽  
Bin Zhao ◽  
Yu Gu ◽  
Yifang Zhu ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Southern California ◽  
Air Pollutant ◽  
Activity Level ◽  
Pollutant Emissions ◽  
Chemical Compositions ◽  
Emission Reductions ◽  
The Impact ◽  
Pm2.5 Concentration

Abstract. In response to the coronavirus disease of 2019 (COVID-19), California issued statewide stay-at-home orders, bringing about abrupt and dramatic reductions in air pollutant emissions. This crisis offers us an unprecedented opportunity to evaluate the effectiveness of emission reductions in terms of air quality. Here we use the Weather Research and Forecasting model with Chemistry (WRF-Chem) in combination with surface observations to study the impact of the COVID-19 lockdown measures on air quality in southern California. Based on activity level statistics and satellite observations, we estimate the sectoral emission changes during the lockdown. Due to the reduced emissions, the population-weighted concentrations of fine particulate matter (PM2.5) decrease by 15 % in southern California. The emission reductions contribute 68 % of the PM2.5 concentration decrease before and after the lockdown, while meteorology variations contribute the remaining 32 %. Among all chemical compositions, the PM2.5 concentration decrease due to emission reductions is dominated by nitrate and primary components. For O3 concentrations, the emission reductions cause a decrease in rural areas but an increase in urban areas; the increase can be offset by a 70 % emission reduction in anthropogenic volatile organic compounds (VOCs). These findings suggest that a strengthened control on primary PM2.5 emissions and a well-balanced control on nitrogen oxides and VOC emissions are needed to effectively and sustainably alleviate PM2.5 and O3 pollution in southern California.

scholarly journals Modeling the Impact of COVID-19 on Air Quality in Southern California: Implications for Future Control Policies

2020 ◽  
Author(s):  
Zhe Jiang ◽  
Hongrong Shi ◽  
Bin Zhao ◽  
Yu Gu ◽  
Yifang Zhu ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Southern California ◽  
Air Pollutant ◽  
Activity Level ◽  
Pollutant Emissions ◽  
Chemical Compositions ◽  
Emission Reductions ◽  
The Impact ◽  
Pm2.5 Concentration

Abstract. In response to the Coronavirus Disease 2019 (COVID-19), California issued statewide stay-at-home orders, bringing about abrupt and dramatic reductions in air pollutant emissions. This crisis offers us an unprecedented opportunity to evaluate the effectiveness of emission reductions on air quality. Here we use the Weather Research and Forecasting model with Chemistry (WRF-Chem) in combination with surface observations to study the impact of the COVID-19 lockdown measures on air quality in southern California. Based on activity level statistics and satellite observations, we estimate the sectoral emission changes during the lockdown. Due to the reduced emissions, the population-weighted concentrations of fine particulate matter (PM2.5) decrease by 15 % in southern California. The emission reductions contribute 68 % of the PM2.5 concentration decrease before and after the lockdown, while meteorology variations contribute the remaining 32 %. Among all chemical compositions, the PM2.5 concentration decrease due to emission reductions is dominated by nitrate and primary components. For O3 concentrations, the emission reductions cause a decrease in rural areas but an increase in urban areas; the increase can be offset by a 70 % emission reduction in anthropogenic volatile organic compounds (VOC). These findings suggest that a strengthened control on primary PM2.5 emissions and a well-balanced control on nitrogen oxides and VOC emissions are needed to effectively and sustainably alleviate PM2.5 and O3 pollution in southern California.

Status of Air Pollutant Emissions and Health Impact of LNG Cogeneration Plant in Administrative City, Republic of Korea

2020 ◽  
Author(s):  
Yumi Kim
Keyword(s):  
Power Plant ◽  
Urban Areas ◽  
Air Pollutants ◽  
Health Impact ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Risk Level ◽  
Cogeneration Plant ◽  
Impact Prediction ◽  
The Impact

<p><span><span>Along with the development of new cities, the construction of LNG cogeneration plant in urban areas is being promoted, and the facility has been pointed out as one of the major air pollution sources along with many vehicles in urban areas. For example, the construction of a new administrative city in Korea has led to the relocation of major government buildings and the influx of more than 300,000 people. The city has a 530 MW power plant + 391 Gcal/h district heating facility. The facility released 294,835 kg and 325,381 kg of NOx annually in 2017 and 2018, respectively. When examining the impact, we analyzed the impact of air pollutants (PM<sub>2.5</sub>, O<sub>3</sub>, NO<sub>2</sub>, etc.) through CMAQ modeling. In addition, the impact prediction using AERMOD related to the release of carcinogenic air pollutants is estimated to be no more than 10<sup>-5</sup> (risk level), but measurement and verification are required. In addition to concentration-based risk assessments, health impact assessments are needed that consider the number of populations exposed. In this study, QGIS was used to calculate population. In conclusion, even if the same LNG power plant is constructed, the LNG cogeneration plant located adjacent to a large residential facility requires air pollutant management measures according to the exposure population by radius of influence</span></span></p><p> </p>

scholarly journals Assessing the Impact of Road Traffic Reorganization on Air Quality: A Street Canyon Case Study

Atmosphere ◽  
2020 ◽  
Vol 11 (7) ◽  
pp. 695
Author(s):  
Marek Bogacki ◽  
Robert Oleniacz ◽  
Mateusz Rzeszutek ◽  
Paulina Bździuch ◽  
Adriana Szulecka ◽  
...  
Keyword(s):  
Air Quality ◽  
Road Traffic ◽  
Road Transport ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Maximum Speed ◽  
Commercial Vehicles ◽  
The Road ◽  
Management Changes ◽  
The Impact

One of the elements of strategy aimed at minimizing the impact of road transport on air quality is the introduction of its reorganization resulting in decreased pollutant emissions to the air. The aim of the study was to determine the optimal strategy of corrective actions in terms of the air pollutant emissions from road transport. The study presents the assessment results of the emission reduction degree of selected pollutants (PM10, PM2.5, and NOx) as well as the impact evaluation of this reduction on their concentrations in the air for adopted scenarios of the road management changes for one of the street canyons in Krakow (Southern Poland). Three scenarios under consideration of the city authorities were assessed: narrowing the cross-section of the street by eliminating one lane in both directions, limiting the maximum speed from 70 km/h to 50 km/h, and allowing only passenger and light commercial vehicles on the streets that meet the Euro 4 standard or higher. The best effects were obtained for the variant assuming banning of vehicles failing to meet the specified Euro standard. It would result in a decrease of the yearly averaged PM10 and PM2.5 concentrations by about 8–9% and for NOx by almost 30%.

scholarly journals Changes in Air Quality Associated with Mobility Trends and Meteorological Conditions during COVID-19 Lockdown in Northern England, UK

Atmosphere ◽  
2021 ◽  
Vol 12 (4) ◽  
pp. 504
Author(s):  
Said Munir ◽  
Gulnur Coskuner ◽  
Majeed Jassim ◽  
Yusuf Aina ◽  
Asad Ali ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Human Life ◽  
Additive Model ◽  
Positive Association ◽  
Air Pollutant ◽  
Back Trajectory ◽  
Generalised Additive Model ◽  
Mobility Data ◽  
The Impact

The COVID-19 pandemic triggered catastrophic impacts on human life, but at the same time demonstrated positive impacts on air quality. In this study, the impact of COVID-19 lockdown interventions on five major air pollutants during the pre-lockdown, lockdown, and post-lockdown periods is analysed in three urban areas in Northern England: Leeds, Sheffield, and Manchester. A Generalised Additive Model (GAM) was implemented to eliminate the effects of meteorological factors from air quality to understand the variations in air pollutant levels exclusively caused by reductions in emissions. Comparison of lockdown with pre-lockdown period exhibited noticeable reductions in concentrations of NO (56.68–74.16%), NO2 (18.06–47.15%), and NOx (35.81–56.52%) for measured data. However, PM10 and PM2.5 levels demonstrated positive gain during lockdown ranging from 21.96–62.00% and 36.24–80.31%, respectively. Comparison of lockdown period with the equivalent period in 2019 also showed reductions in air pollutant concentrations, ranging 43.31–69.75% for NO, 41.52–62.99% for NOx, 37.13–55.54% for NO2, 2.36–19.02% for PM10, and 29.93–40.26% for PM2.5. Back trajectory analysis was performed to show the air mass origin during the pre-lockdown and lockdown periods. Further, the analysis showed a positive association of mobility data with gaseous pollutants and a negative correlation with particulate matter.

scholarly journals Response of atmospheric composition to COVID-19 lockdown measures during Spring in the Paris region (France)

2021 ◽  
Author(s):  
Jean-Eudes Petit ◽  
Jean-Charles Dupont ◽  
Olivier Favez ◽  
Valérie Gros ◽  
Yunjiang Zhang ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Meteorological Conditions ◽  
In Situ Monitoring ◽  
Pollutant Emissions ◽  
Atmospheric Composition ◽  
Secondary Pollutants ◽  
The Impact ◽  
Mitigation Policies

Abstract. Since early 2020, the COVID-19 pandemic has led to lockdowns at national scales. These lockdowns resulted in large cuts of atmospheric pollutant emissions, notably related to the vehicular traffic source where daily commuting of light-duty vehicles was almost completely stopped in numerous urban areas worldwide, especially during Spring 2020. As a result, air quality changed in manners that are still currently under investigation. Long-term in-situ monitoring of atmospheric composition provides, to this perspective, essential information. However, a robust quantitative assessment of the impact of lockdown measures on ambient concentrations is hindered by weather variability. Basic comparisons with previous years may thus be flawed, especially regarding secondary pollutants, whose concentrations strongly depends on meteorological conditions. In order to circumvent this difficulty, an innovative methodology has been developed. The Analog Application for Air Quality (A3Q) method is based on the comparison of each day of lockdown to a group of analog days having similar meteorological conditions. The A3Q method has been successfully evaluated and applied to a comprehensive in-situ dataset of primary and secondary pollutants obtained at the SIRTA observatory, a suburban background site of the Paris megacity (France). The overall slight decrease of PM1 concentrations (−14 %) compared to business-as-usual conditions conceals contrasting behaviours. Primary traffic tracers (NOx and traffic-related carbonaceous aerosols) dropped by 42–66 % during the lockdown period. Further, the A3Q method enabled us to characterize of changes triggered by NOx decreases. Particulate nitrate and secondary organic aerosols (SOA), two of the main springtime aerosol components in North-Western Europe, decreased by −45 % and −25 %, respectively. A NOx-relationship emphasizes the interest of NOx mitigation policies at the regional (i.e. city) scale, although long-range pollution advection sporadically overcompensated regional decreases. Variations of the oxidation state of SOA suggests discrepancies in SOA formation processes. At the same time, the expected ozone increase (+20 %) underlines the negative feedback of NO titration. These results provide a quasi-comprehensive observation-based insight on mitigation policies regarding air quality in future low-carbon urban areas.

scholarly journals Analysis of the Main Anthropogenic Sources’ Contribution to Pollutant Emissions in the Lazio Region, Italy

2021 ◽  
Vol 11 (17) ◽  
pp. 7936
Author(s):  
Gabriele Battista ◽  
Emanuele de Lieto Vollaro ◽  
Roberto de Lieto Vollaro
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Air Pollutants ◽  
Global Climate ◽  
Atmospheric Stability ◽  
Air Pollutant ◽  
Urban Traffic ◽  
Pollutant Emissions ◽  
Anthropogenic Sources ◽  
Lazio Region

Most cities worldwide suffer from serious air-quality problems, which have received increasing attention in the past decade. The most probable reason for the air-quality problems is the urban population growth, combined with a change in land use due to increasing urban areas. The emission of air pollutants is caused by different anthropogenic processes which can be categorized into the sources of urban traffic, industry, and domestic heating. Dispersion and dilution of air pollutants are strongly influenced by meteorological conditions, especially by wind direction, wind speed, turbulence, and atmospheric stability. With an increasing number of people living in cities, there is the need to examine the correlation between air pollution, local climate, and the effects these changes have on global climate. New interdisciplinary research studies are needed to increase our understanding of the interactions among these aspects. The aim is to analyze the pollutant condition in Rome and the other provinces of the Lazio region with qualitative and quantitative analysis, in order to understand which are the main pollutant sources and what is the correlation of habits of the population on air pollutant emissions.

scholarly journals European atmosphere in 2050, a regional air quality and climate perspective under CMIP5 scenarios

2013 ◽  
Vol 13 (15) ◽  
pp. 7451-7471 ◽  
Author(s):  
A. Colette ◽  
B. Bessagnet ◽  
R. Vautard ◽  
S. Szopa ◽  
S. Rao ◽  
...  
Keyword(s):  
Climate Change ◽  
Air Pollution ◽  
Air Quality ◽  
Regional Scale ◽  
Air Pollutant ◽  
External Factors ◽  
Pollutant Emissions ◽  
Reference Scenario ◽  
Regional Air Quality ◽  
The Impact

Abstract. To quantify changes in air pollution over Europe at the 2050 horizon, we designed a comprehensive modelling system that captures the external factors considered to be most relevant, and that relies on up-to-date and consistent sets of air pollution and climate policy scenarios. Global and regional climate as well as global chemistry simulations are based on the recent representative concentration pathways (RCP) produced for the Fifth Assessment Report (AR5) of the IPCC (Intergovernmental Panel on Climate Change) whereas regional air quality modelling is based on the updated emissions scenarios produced in the framework of the Global Energy Assessment. We explored two diverse scenarios: a reference scenario where climate policies are absent and a mitigation scenario which limits global temperature rise to within 2 °C by the end of this century. This first assessment of projected air quality and climate at the regional scale based on CMIP5 (5th Coupled Model Intercomparison Project) climate simulations is in line with the existing literature using CMIP3. The discrepancy between air quality simulations obtained with a climate model or with meteorological reanalyses is pointed out. Sensitivity simulations show that the main factor driving future air quality projections is air pollutant emissions, rather than climate change or intercontinental transport of pollution. Whereas the well documented "climate penalty" that weights upon ozone (increase of ozone pollution with global warming) over Europe is confirmed, other features appear less robust compared to the literature, such as the impact of climate on PM2.5. The quantitative disentangling of external factors shows that, while several published studies focused on the climate penalty bearing upon ozone, the contribution of the global ozone burden is somewhat overlooked in the literature.

scholarly journals European atmosphere in 2050, a regional air quality and climate perspective under CMIP5 scenarios

2013 ◽  
Vol 13 (3) ◽  
pp. 6455-6499 ◽  
Author(s):  
A. Colette ◽  
B. Bessagnet ◽  
R. Vautard ◽  
S. Szopa ◽  
S. Rao ◽  
...  
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Climate Model ◽  
Regional Climate ◽  
Regional Scale ◽  
Air Pollutant ◽  
Pollutant Emissions ◽  
Reference Scenario ◽  
Regional Air Quality ◽  
The Impact

Abstract. To quantify changes in air pollution in Europe at the 2050 horizon, we designed a comprehensive modelling system that captures the external factors considered to be most relevant and relies on up-to-date and consistent sets of air pollution and climate policy scenarios. Global and regional climate as well as global chemistry simulations are based on the recent Representative Concentrations Pathways (RCP) produced for the Fifth Assessment Report (AR5) of IPCC whereas regional air quality modelling is based on the updated emissions scenarios produced in the framework of the Global Energy Assessment. We explored two diverse scenarios: a reference scenario where climate policies are absent and a mitigation scenario which limits global temperature rise to within 2 °C by the end of this century. This first assessment of projected air quality and climate at the regional scale based on CMIP5 (5th Climate Model Intercomparison Project) climate simulations is in line with the existing literature using CMIP3. The discrepancy between air quality simulations obtained with a climate model or with meteorological reanalyses is pointed out. Sensitivity simulations show that the main factor driving future air quality projections is air pollutant emissions, rather than climate change or long range transport. Whereas the well documented "climate penalty" bearing upon ozone over Europe is confirmed, other features appear less robust compared to the literature: such as the impact of climate on PM2.5. The quantitative disentangling of each contributing factor shows that the magnitude of the ozone climate penalty has been overstated in the past while on the contrary the contribution of the global ozone burden is overlooked in the literature.

scholarly journals Response of atmospheric composition to COVID-19 lockdown measures during spring in the Paris region (France)

2021 ◽  
Vol 21 (22) ◽  
pp. 17167-17183
Author(s):  
Jean-Eudes Petit ◽  
Jean-Charles Dupont ◽  
Olivier Favez ◽  
Valérie Gros ◽  
Yunjiang Zhang ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Pollutant Emissions ◽  
Atmospheric Composition ◽  
Carbonaceous Aerosols ◽  
Low Carbon ◽  
Atmospheric Pollutant ◽  
Ambient Concentrations ◽  
The Impact ◽  
Mitigation Policies

Abstract. Since early 2020, the COVID-19 pandemic has led to lockdowns at national scales. These lockdowns resulted in large cuts of atmospheric pollutant emissions, notably related to the vehicular traffic source, especially during spring 2020. As a result, air quality changed in manners that are still currently under investigation. The robust quantitative assessment of the impact of lockdown measures on ambient concentrations is however hindered by weather variability. In order to circumvent this difficulty, an innovative methodology has been developed. The Analog Application for Air Quality (A3Q) method is based on the comparison of each day of lockdown to a group of analog days having similar meteorological conditions. The A3Q method has been successfully evaluated and applied to a comprehensive in situ dataset of primary and secondary pollutants obtained at the SIRTA observatory, a suburban background site of the megacity of Paris (France). The overall slight decrease of submicron particulate matter (PM1) concentrations (−14 %) compared to business-as-usual conditions conceals contrasting behaviors. Primary traffic tracers (NOx and traffic-related carbonaceous aerosols) dropped by 42 %–66 % during the lockdown period. Further, the A3Q method enabled us to characterize changes triggered by NOx decreases. Particulate nitrate and secondary organic aerosols (SOAs), two of the main springtime aerosol components in northwestern Europe, decreased by −45 % and −25 %, respectively. A NOx relationship emphasizes the interest of NOx mitigation policies at the regional (i.e., city) scale, although long-range pollution advection sporadically overcompensated for regional decreases. Variations of the oxidation state of SOA suggest discrepancies in SOA formation processes. At the same time, the expected ozone increase (+20 %) underlines the negative feedback of NO titration. These results provide a quasi-comprehensive observation-based insight for mitigation policies regarding air quality in future low-carbon urban areas.

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