scholarly journals Effect of accounting for public holidays on skills of atmospheric composition model SILAM v.5.7

2021 ◽  
Author(s):  
Yalda Fatahi ◽  
Rostislav Kouznetsov ◽  
Mikhail Sofiev
Keyword(s):  
Transport Model ◽  
Positive Impact ◽  
Sensitivity Study ◽  
Bias Reduction ◽  
Air Pollutant ◽  
Added Value ◽  
Atmospheric Composition ◽  
Anthropogenic Activity ◽  
Pollutant Concentrations ◽  
Public Holidays

Abstract. Changes in anthropogenic activity during public holidays influence air pollutant concentrations. The objective of this study is to quantify the public holiday’s effect on air quality and to analyse the added value of accounting for the holidays in AQ modelling and forecasting. Spatial and temporal distributions of atmospheric concentrations of the major air pollutants (PM2.5, PM10, SO2, CO, NO2, NOX, and O3) were considered at the European scale for all public holidays of 2018. Particular attention was given to the events with the most-pronounced continental or regional impact: Christmas and New Year, Easter, May vacations and last days of Ramadan. The simulations were performed with the Eulerian chemistry transport model SILAM v.5.7. Three model runs were performed: the baseline with no treatment of holidays, the run considering the holidays as Sundays, and the run forcing 80 % reduction of emissions for the week-day sensitive sectors. . The emission scaling was applied on a country basis. The model predictions were compared with in-situ observations collected by the European Environment Agency. The experiment showed that even conservative treatment of official holidays has a large positive impact on NOx (up to 30 % of bias reduction in the holiday days) and also improves the CO, PM2.5 and O3 predictions. In many cases, the sensitivity study suggested deeper emission reduction than the level of Sundays. An individual consideration of the holiday events in different countries may further improve their representation in the models: specific diurnal pattern of emissions, additional emission due to fireworks, different driving patterns, etc.

scholarly journals The effect of accounting for public holidays on the skills of the atmospheric composition model SILAM v.5.7

2021 ◽  
Vol 14 (12) ◽  
pp. 7459-7475
Author(s):  
Yalda Fatahi ◽  
Rostislav Kouznetsov ◽  
Mikhail Sofiev
Keyword(s):  
Transport Model ◽  
Positive Impact ◽  
Regional Scale ◽  
Added Value ◽  
Atmospheric Composition ◽  
Integrated Modelling ◽  
May Day ◽  
Emission Changes ◽  
Public Holidays ◽  
The Impact

Abstract. This study quantifies the impact of emission changes during public holidays on air quality (AQ) and analyses the added value of accounting for the holidays in AQ modelling. Spatial and temporal distributions of atmospheric concentrations of the major air pollutants (the main focus was on NO2, but we also included O3, CO, PM2.5, and SO2) were considered at the European scale for all public holidays of 2018. Particular attention was paid to the events with the most pronounced continental- or regional-scale impact: Christmas and New Year, Easter, May Day vacations, and the last days of Ramadan. The simulations were performed with the chemistry transport model SILAM v.5.7 (System for Integrated modeLling of Atmospheric coMposition). Three model runs were made: the baseline with no treatment of holidays, the run considering holidays as Sundays, and the run forcing 80 % reduction in emissions during holidays for the weekday-sensitive sectors. The emission scaling was applied on a country basis. The model predictions were compared with in situ observations collected by the European Environment Agency. The experiment showed that even conservative treatment of official holidays has a large positive impact on NOx (up to 30 % of reduction in the bias inhomogeneity during the holiday days) and improves the CO, PM2.5, and O3 predictions. In many cases, the sensitivity simulations suggested a greater emission reduction than the level of Sundays. An individual consideration of the holiday events in different countries may further improve their representation in the models: specific diurnal pattern of emissions, additional emission due to fireworks, and different driving patterns.

scholarly journals Phase Wise Variation of Criteria Pollutants across India during COVID-19 Lockdown

2021 ◽  
Vol 04 (10) ◽  
Author(s):  
Charu Tyagi ◽  
Keyword(s):  
Anthropogenic Activities ◽  
Phase 1 ◽  
Air Pollutant ◽  
Atmospheric Composition ◽  
Mitigation Measures ◽  
Criteria Pollutants ◽  
Mixed Response ◽  
Pollutant Concentrations ◽  
Maximum Decrease ◽  
Air Pollutant Concentrations

The COVID-19 epidemic forced many countries around the world to lockdown completely. This occlusion influenced the atmospheric composition positively due to reduced anthropogenic activities. Recently, many studies across India have shown how the COVID-19 lockdown has affected air quality in different cities. However, these studies did not examine the phased percentage variation in air pollutant concentrations across different states of India. In this study, percentage variation in the concentration of five criteria pollutant, PM10, PM2.5, NO2, CO and Ozone were studied for 13 states across India during four phases of COVID-19 lockdown. A significant decrease in air pollutant levels was observed in all four phases, with phase 1 and phase 2 reporting a maximum decrease. PM10 and PM2.5, CO and NO2 showed a decrease in concentration in all states. Ozone showed a mixed response, with both increase and decrease recorded across states. During the COVID-19 lockdown period in India, AOD levels were reduced by 10.25%. This study will certainly help regulators set the guidelines and mitigation measures for appropriate control of air pollutants in different states in future.

scholarly journals The influence of biomass burning on the global distribution of selected non-methane organic compounds

2013 ◽  
Vol 13 (2) ◽  
pp. 851-867 ◽  
Author(s):  
A. C. Lewis ◽  
M. J. Evans ◽  
J. R. Hopkins ◽  
S. Punjabi ◽  
K. A. Read ◽  
...  
Keyword(s):  
Air Quality ◽  
Organic Compounds ◽  
Biomass Burning ◽  
Transport Model ◽  
Developed Countries ◽  
Air Pollutant ◽  
Anthropogenic Activity ◽  
Chemical Transport Model ◽  
Benzene Toluene ◽  
Emission Ratios

Abstract. Forests fires are a significant source of chemicals to the atmosphere including numerous non-methane organic compounds (NMOCs). We report airborne measurement of hydrocarbons, acetone and methanol from >500 whole air samples collected over Eastern Canada, including interceptions of several different boreal biomass burning plumes. From these and concurrent measurements of carbon monoxide (CO) we derive fire emission ratios for 29 different organic species relative to the emission of CO. These range from 8.9 ± 3.2 ppt ppb−1 CO for methanol to 0.007 ± 0.004 ppt ppb−1 CO for cyclopentane. The ratios are in good to excellent agreement with literature values. Using the GEOS-Chem global 3-D chemical transport model (CTM) we show the influence of biomass burning on the global distributions of benzene, toluene, ethene and propene (species which are controlled for air quality purposes and sometimes used as indicative tracers of anthropogenic activity). Using our observationally derived emission ratios and the GEOS-Chem CTM, we show that biomass burning can be the largest fractional contributor to observed benzene, toluene, ethene and propene levels in many global locations. The widespread biomass burning contribution to atmospheric benzene, a heavily regulated air pollutant, suggests that pragmatic approaches are needed when setting air quality targets as tailpipe and solvent emissions decline in developed countries. We subsequently determine the extent to which the 28 global-status World Meteorological Organisation – Global Atmosphere Watch stations worldwide are influenced by biomass burning sourced benzene, toluene, ethene and propene as compared to their exposure to anthropogenic emissions.

scholarly journals The influence of boreal forest fires on the global distribution of non-methane hydrocarbons

2012 ◽  
Vol 12 (9) ◽  
pp. 23433-23469 ◽  
Author(s):  
A. C. Lewis ◽  
M. J. Evans ◽  
J. R. Hopkins ◽  
S. Punjabi ◽  
K. A. Read ◽  
...  
Keyword(s):  
Boreal Forest ◽  
Biomass Burning ◽  
Forest Fires ◽  
Transport Model ◽  
Air Pollutant ◽  
Anthropogenic Activity ◽  
Chemical Transport Model ◽  
Airborne Measurements ◽  
Benzene Toluene ◽  
Emission Ratios

Abstract. Boreal forest fires are a significant source of chemicals to the atmosphere including numerous non-methane hydrocarbons (NMHCs). We report airborne measurements of NMHCs, acetone and methanol from > 500 whole air samples collected over Eastern Canada, including interception of several different boreal biomass burning plumes. From these and concurrent measurements of carbon monoxide (CO) we derive fire emission ratios for 29 different species relative to the emission of CO. These range from 8.9 ± 3.2 ppt ppb−1 CO for methanol to 0.007 ± 0.004 ppt ppb−1 CO for cyclopentane. The ratios are in good to excellent agreement with recent literature values. Using the GEOS-Chem global 3-D chemical transport model (CTM) we show the influence of biomass burning on the global distributions of benzene, toluene, ethene and propene (species considered generally as indicative tracers of anthropogenic activity). Using our derived emission ratios and the GEOS-Chem CTM, we show that biomass burning can be the largest fractional contributor to observed benzene, toluene, ethene and propene in many global locations. The widespread biomass burning contribution to atmospheric benzene, a heavily regulated air pollutant, suggests that pragmatic approaches are needed when setting air quality targets as tailpipe and solvent emissions continue to decline. We subsequently determine the extent to which the 28 Global WMO-GAW stations worldwide are influenced by biomass burning sourced benzene, toluene, ethene and propene when compared to their exposure to anthropogenic emissions.

scholarly journals Monitoring aerosols over Europe: an assessment of the potential benefit of assimilating the VIS04 measurements from the future MTG/FCI geostationary imager

2019 ◽  
Vol 12 (2) ◽  
pp. 1251-1275 ◽  
Author(s):  
Maxence Descheemaecker ◽  
Matthieu Plu ◽  
Virginie Marécal ◽  
Marine Claeyman ◽  
Francis Olivier ◽  
...  
Keyword(s):  
Transport Model ◽  
Positive Impact ◽  
Low Earth Orbit ◽  
Added Value ◽  
Spatial And Temporal Patterns ◽  
Future Space ◽  
The Future ◽  
General Benefit ◽  
Pollution Event ◽  
Observing System Simulation Experiment

Abstract. The study assesses the possible benefit of assimilating aerosol optical depth (AOD) from the future space-borne sensor FCI (Flexible Combined Imager) for air quality monitoring in Europe. An observing system simulation experiment (OSSE) was designed and applied over a 4-month period, which includes a severe-pollution episode. The study focuses on the FCI channel centred at 444 nm, which is the shortest wavelength of FCI. A nature run (NR) and four different control runs of the MOCAGE chemistry transport model were designed and evaluated to guarantee the robustness of the OSSE results. The synthetic AOD observations from the NR were disturbed by errors that are typical of the FCI. The variance of the FCI AOD at 444 nm was deduced from a global sensitivity analysis that took into account the aerosol type, surface reflectance and different atmospheric optical properties. The experiments show a general benefit to all statistical indicators of the assimilation of the FCI AOD at 444 nm for aerosol concentrations at the surface over Europe, and also a positive impact during the severe-pollution event. The simulations with data assimilation reproduced spatial and temporal patterns of PM10 concentrations at the surface better than those without assimilation all along the simulations and especially during the pollution event. The advantage of assimilating AODs from a geostationary platform over a low Earth orbit satellite has also been quantified. This work demonstrates the capability of data from the future FCI sensor to bring added value to the MOCAGE aerosol simulations, and in general, to other chemistry transport models.

scholarly journals Risk Assessment and Air Quality Study during Different Phases of COVID-19 Lockdown in an Urban Area of Klang Valley, Malaysia

2021 ◽  
Vol 13 (21) ◽  
pp. 12217
Author(s):  
Mohd Shahrul Mohd Nadzir ◽  
Mohd Zaim Mohd Nor ◽  
Mohd Fadzil Firdzaus Mohd Nor ◽  
Muhamad Ikram A Wahab ◽  
Sawal Hamid Md Ali ◽  
...  
Keyword(s):  
Air Quality ◽  
Air Pollutants ◽  
Positive Impact ◽  
Movement Control ◽  
Air Pollutant ◽  
Pollutant Concentrations ◽  
The World ◽  
Klang Valley ◽  
Air Pollutant Concentrations ◽  
Control Order

Globally, the COVID-19 pandemic has had both positive and negative impacts on humans and the environment. In general, a positive impact can be seen on the environment, especially in regard to air quality. This positive impact on air quality around the world is a result of movement control orders (MCO) or lockdowns, which were carried out to reduce the cases of COVID-19 around the world. Nevertheless, data on the effects on air quality both during and post lockdown at local scales are still sparse. Here, we investigate changes in air quality during normal days, the MCOs (MCO 1, 2 and 3) and post MCOs, namely the Conditional Movement Control Order (CMCO) and the Recovery Movement Control Order (RMCO) in the Klang Valley region. In this study, we used the air sensor network AiRBOXSense that measures carbon monoxide (CO), nitrogen dioxide (NO2), sulfur dioxide (SO2) and particulate matter (PM2.5 and PM10) at Petaling Jaya South (PJS), Kelana Jaya (KJ) and Kota Damansara (KD). The results showed that the daily average concentrations of CO and NO2 mostly decreased in the order of normal days > MCO (MCO 1, 2 and 3) > CMCO > RMCO. PM10, PM2.5, SO2 and O3 showed a decrease from the MCO to RMCO. PJS showed that air pollutant concentrations decreased from normal days to the lockdown phases. This clearly shows the effects of ‘work from home’ orders at all places in the PJS city. The greatest percentage reductions in air pollutants were observed during the change from normal days to MCO 1 (24% to 64%), while during MCO 1 to MCO 2, the concentrations were slightly increased during the changes of the lockdown phase, except for SO2 and NO2 over PJS. In KJ, most of the air pollutants decreased from MCO 1 to MCO 3 except for CO. However, the percentage reduction and increments of the gas pollutants were not consistent during the different phases of lockdown, and this effect was due to the sensor location—only 20 m from the main highway (vehicle emissions). The patterns of air pollutant concentrations over the KD site were similar to the PJS site; however, the percentage reduction and increases of PM2.5, O3, SO2 and CO were not consistent. We believe that local burning was the main contribution to these unstable patterns during the lockdown period. The cause of these different changes in concentrations may be due to the relaxation phases during the lockdown at each station, where most of the common activities, such as commuting and industrial activities changed in frequency from the MCO, CMCO and RMCO. Wind direction also affected the concentrations, for example, during the CMCO and RMCO, most of the pollutants were blowing in from the Southeast region, which mostly consists of a city center and industrial areas. There was a weak correlation between air pollutants and the temperature and relative humidity at all stations. Health risk assessment analysis showed that non-carcinogenic risk health quotient (HQ) values for the pollutants at all stations were less than 1, suggesting unlikely non-carcinogenic effects, except for SO2 (HQ > 1) in KJ. The air quality information showed that reductions in air pollutants can be achieved if traffic and industry emissions are strictly controlled.

scholarly journals Nonstationary modeling of NO<sub>2</sub>, NO and NO<sub><i>x</i></sub> in Paris using the Street-in-Grid model: coupling local and regional scales with a two-way dynamic approach

2020 ◽  
Vol 20 (13) ◽  
pp. 7717-7740
Author(s):  
Lya Lugon ◽  
Karine Sartelet ◽  
Youngseob Kim ◽  
Jérémy Vigneron ◽  
Olivier Chrétien
Keyword(s):  
Transport Model ◽  
Regional Scale ◽  
Chemical Transport ◽  
Added Value ◽  
Scale Model ◽  
Background Concentrations ◽  
Chemical Transport Model ◽  
Time Step ◽  
Multi Scale ◽  
Pollutant Concentrations

Abstract. Regional-scale chemistry-transport models have coarse spatial resolution (coarser than 1 km ×1 km) and can thus only simulate background concentrations. They fail to simulate the high concentrations observed close to roads and in streets, where a large part of the urban population lives. Local-scale models may be used to simulate concentrations in streets. They often assume that background concentrations are constant and/or use simplified chemistry. Recently developed, the multi-scale model Street-in-Grid (SinG) estimates gaseous pollutant concentrations simultaneously at local and regional scales by coupling them dynamically. This coupling combines the regional-scale chemistry-transport model Polair3D and a street-network model, the Model of Urban Network of Intersecting Canyons and Highway (MUNICH), with a two-way feedback. MUNICH explicitly models street canyons and intersections, and it is coupled to the first vertical level of the chemical-transport model, enabling the transfer of pollutant mass between the street-canyon roof and the atmosphere. The original versions of SinG and MUNICH adopt a stationary hypothesis to estimate pollutant concentrations in streets. Although the computation of the NOx concentration is numerically stable with the stationary approach, the partitioning between NO and NO2 is highly dependent on the time step of coupling between transport and chemistry processes. In this study, a new nonstationary approach is presented with a fine coupling between transport and chemistry, leading to numerically stable partitioning between NO and NO2. Simulations of NO, NO2 and NOx concentrations over Paris with SinG, MUNICH and Polair3D are compared to observations at traffic and urban stations to estimate the added value of multi-scale modeling with a two-way dynamical coupling between the regional and local scales. As expected, the regional chemical-transport model underestimates NO and NO2 concentrations in the streets. However, there is good agreement between the measurements and the concentrations simulated with MUNICH and SinG. The two-way dynamic coupling between the local and regional scales tends to be important for streets with an intermediate aspect ratio and with high traffic emissions.

scholarly journals Monitoring aerosols over Europe: an assessment of the potential benefit of assimilating the VIS04 measurements from the future MTG/FCI geostationary imager

2018 ◽  
Author(s):  
Maxence Descheemaecker ◽  
Matthieu Plu ◽  
Virginie Marécal ◽  
Marine Claeyman ◽  
Francis Olivier ◽  
...  
Keyword(s):  
Transport Model ◽  
Positive Impact ◽  
Added Value ◽  
Spatial And Temporal Patterns ◽  
Transport Models ◽  
Chemistry Transport Model ◽  
The Future ◽  
General Benefit ◽  
Pollution Event ◽  
Observing System Simulation Experiment

Abstract. The study assesses the possible benefit of assimilating Aerosol Optical Depth (AOD) from the future spaceborne sensor FCI (Flexible Combined Imager) for air quality monitoring in Europe. An Observing System Simulation Experiment (OSSE) was designed and applied over a 4-months period that includes a severe pollution episode. The study focuses on the FCI channel centred at 444 nm, which is the shortest wavelength of FCI. A Nature Run (NR) and four different Control Runs of the MOCAGE chemistry-transport model were designed and evaluated to guarantee the robustness of the OSSE results. The AOD synthetic observations from the NR were disturbed by errors that are typical of the FCI. The variance of the FCI AOD at 444 nm was deduced from a global sensitivity analysis that took into account the aerosol type, surface reflectance and different atmospheric optical properties. The experiments show a general benefit on all statistical indicators of the assimilation of the FCI AOD at 444 nm for aerosol concentrations at surface over Europe, and also a positive impact during the severe pollution event. The simulations with data assimilation reproduced spatial and temporal patterns of PM10 concentrations at surface better than without assimilation all along the simulations and especially during the pollution event. This work demonstrates the capability of data from the future FCI sensor to bring an added value to the MOCAGE aerosol simulations, and in general, to other chemistry transport models.

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