scholarly journals Concentration and Physical Characteristics of Black Carbon in Winter Snow of Beijing in 2015

Atmosphere ◽  
2021 ◽  
Vol 12 (7) ◽  
pp. 816
Author(s):  
Delong Zhao ◽  
Jiujiang Sheng ◽  
Yuanmou Du ◽  
Wei Zhou ◽  
Fei Wang ◽  
...  
Keyword(s):  
Particle Size ◽  
Black Carbon ◽  
Urban Areas ◽  
Average Concentration ◽  
Beijing Area ◽  
Pollution Levels ◽  
Local Pollution ◽  
East Wind ◽  
Winter Snow ◽  
Log Normal

In Beijing, the probability of snowfall is decreasing as a result of global warming. At the same time, Beijing has suffered severe air pollution. In this paper, the concentration and particle size characteristics of BC (Black Carbon) in snow during the winter of 2015 in Beijing were analyzed by the SP2 method. The average concentration of BC in snow meltwater in Beijing is 82 ng/mL, with a minimum value of 62.9 ng/mL and a maximum of 210.6 ng/mL. The BC particle size in snow and ice in the Beijing area is mostly concentrated in the range of 70–400 nm. After log-normal, the BC particle size above 600 nm is still small, which should be closely related to the nature of the local BC emission source. The concentration of BC in snow is highly susceptible to meteorological conditions and local pollution levels. When Beijing is under the control of the east wind or the southeast wind, aerosols in the urban areas can easily accumulate in the northwestern mountains and then settle or participate in the snowfall process, resulting in an increase in BC aerosol accumulation in the snow, thus further changing the optical properties of snow in the Beijing area.

scholarly journals Study of Temporal Variations of Equivalent Black Carbon in a Coastal City in Northwest Spain Using an Atmospheric Aerosol Data Management Software

2021 ◽  
Vol 11 (2) ◽  
pp. 516
Author(s):  
María Piñeiro-Iglesias ◽  
Javier Andrade-Garda ◽  
Sonia Suárez-Garaboa ◽  
Soledad Muniategui-Lorenzo ◽  
Purificación López-Mahía ◽  
...  
Keyword(s):  
Data Management ◽  
Black Carbon ◽  
Light Absorption ◽  
Atmospheric Aerosol ◽  
Urban Areas ◽  
Radiative Properties ◽  
Anthropogenic Sources ◽  
Biomass Combustion ◽  
Management Support ◽  
Diurnal Variability

Light-absorbing carbonaceous aerosols (including black carbon (BC)) pose serious health issues and play significant roles in atmospheric radiative properties. Two-year measurements (2015–2016) of aerosol light absorption, combined with measurements of sub-micrometric particles, were continuously conducted in A Coruña (northwest (NW) Spain) to determine their light absorption properties: absorption coefficients (σabs) and the absorption Ångström exponent (AAE). The mean and standard deviation of equivalent black carbon (eBC) during the period of study were 0.85 ± 0.83 µg m−3, which are lower than other values measured in urban areas of Spain and Europe. High eBC concentrations found in winter are associated with an increase in emissions from anthropogenic sources in combination with lower mixing layer heights and frequent stagnant conditions. The pronounced diurnal variability suggests a strong influence from local sources. AAE had an average value of 1.26 ± 0.22 which implies that both fossil fuel combustion and biomass burning influenced optical aerosol properties. This also highlights biomass combustion in suburban areas, where the use of wood for domestic heating is encouraged, as an important source of eBC. All data treatment was gathered using SCALA© as atmospheric aerosol data management support software program.

scholarly journals Emission Factors of Black Carbon and Co-pollutants from Diesel Vehicles in Mexico City

2017 ◽  
Author(s):  
Miguel Zavala ◽  
Luisa T. Molina ◽  
Tara I. Yacovitch ◽  
Edward C. Fortner ◽  
Joseph R. Roscioli ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Developing Countries ◽  
Black Carbon ◽  
Mexico City ◽  
Urban Areas ◽  
Fine Particulate Matter ◽  
Emission Factors ◽  
Remote Sensing Technique ◽  
Driving Conditions ◽  
Comparison Of The Results

Abstract. Diesel-powered vehicles are intensively used in urban areas for transporting goods and people but can substantially contribute to high emissions of black carbon (BC), organic carbon (OC), and other gaseous pollutants. Strategies aimed at controlling mobile emissions sources thus have the potential to improve air quality as well as help mitigate impacts of air pollutants on climate, ecosystems, and human health. However, in developing countries there are limited data on the BC and OC emission characteristics of diesel-powered vehicles and thus there are large uncertainties in the estimation of the emission contributions from these sources. We measured BC, OC and other inorganic components of fine particulate matter (PM), as well as carbon monoxide (CO), nitrogen oxides (NOx), sulfur dioxide (SO2), ethane, acetylene, benzene, toluene, and C2-benzenes under real-world driving conditions of 20 diesel-powered vehicles encompassing multiple emission level technologies in Mexico City with the chasing technique using the Aerodyne mobile laboratory. Average BC emission factors ranged from 0.41–2.48 g/kg-fuel depending on vehicle type. The vehicles were also simultaneously measured using the cross-road remote sensing technique to obtain the emission factors of nitrogen oxide (NO), CO, total hydrocarbons, and fine PM, thus allowing the inter-comparison of the results from the two techniques. There is overall good agreement between the two techniques and both can identify high and low emitters but substantial differences were found in some of the vehicles, probably due to the ability of the chasing technique to capture a larger diversity of driving conditions in comparison to the remote sensing technique. A comparison of the results with the US-EPA MOVES-2014b model showed that the model underestimates CO, OC, and selected VOC species whereas there is better agreement for NOx and BC. Larger OC / BC ratios were found in comparison to ratios measured in California using the same technique, further demonstrating the need for using locally-obtained diesel-powered vehicle emission factors database in developing countries in order to reduce the uncertainty in the emissions estimates and to improve the evaluation of the effectiveness of emissions reduction measures.

scholarly journals A framework for IoT-enabled environment aware traffic management

2021 ◽  
Vol 11 (1) ◽  
pp. 518
Author(s):  
Mohamed Fazil Mohamed Firdhous ◽  
B. H. Sudantha ◽  
Naseer Ali Hussien
Keyword(s):  
Traffic Congestion ◽  
Urban Areas ◽  
Traffic Management ◽  
Fine Particles ◽  
Environment Pollution ◽  
Negative Effects ◽  
Traffic Condition ◽  
Pollution Levels ◽  
Transport Services ◽  
The Cost

Vehicular traffic has increased across all over the world especially in urban areas due to many reasons including the reduction in the cost of vehicles, degradation of the quality of public transport services and increased wealth of people. The traffic congestion created by these vehicles causes many problems. Increased environment pollution is one of the most serious negative effects of traffic congestion. Noxious gases and fine particles emitted by vehicles affect people in different ways depending on their age and present health conditions. Professionals and policy makers have devised schemes for better managing traffic in congested areas. These schemes suffer from many shortcomings including the inability to adapt to dynamic changes of traffic patterns. With the development of technology, new applications like Google maps help drivers to select less congested routes. But, the identification of the best route takes only the present traffic condition on different road segments presently. In this paper the authors propose a system that helps drivers select routes based on the present and expected environment pollution levels at critical points in a given area.

scholarly journals Estimating lockdown-induced European NO<sub>2</sub> changes using satellite and surface observations and air quality models

2021 ◽  
Vol 21 (9) ◽  
pp. 7373-7394
Author(s):  
Jérôme Barré ◽  
Hervé Petetin ◽  
Augustin Colette ◽  
Marc Guevara ◽  
Vincent-Henri Peuch ◽  
...  
Keyword(s):  
Machine Learning ◽  
Air Quality ◽  
Urban Areas ◽  
Gradient Boosting ◽  
Quality Models ◽  
Pollution Levels ◽  
Surface Station ◽  
Concentration Changes ◽  
Monitoring Service ◽  
No2 Pollution

Abstract. This study provides a comprehensive assessment of NO2 changes across the main European urban areas induced by COVID-19 lockdowns using satellite retrievals from the Tropospheric Monitoring Instrument (TROPOMI) onboard the Sentinel-5p satellite, surface site measurements, and simulations from the Copernicus Atmosphere Monitoring Service (CAMS) regional ensemble of air quality models. Some recent TROPOMI-based estimates of changes in atmospheric NO2 concentrations have neglected the influence of weather variability between the reference and lockdown periods. Here we provide weather-normalized estimates based on a machine learning method (gradient boosting) along with an assessment of the biases that can be expected from methods that omit the influence of weather. We also compare the weather-normalized satellite-estimated NO2 column changes with weather-normalized surface NO2 concentration changes and the CAMS regional ensemble, composed of 11 models, using recently published estimates of emission reductions induced by the lockdown. All estimates show similar NO2 reductions. Locations where the lockdown measures were stricter show stronger reductions, and, conversely, locations where softer measures were implemented show milder reductions in NO2 pollution levels. Average reduction estimates based on either satellite observations (−23 %), surface stations (−43 %), or models (−32 %) are presented, showing the importance of vertical sampling but also the horizontal representativeness. Surface station estimates are significantly changed when sampled to the TROPOMI overpasses (−37 %), pointing out the importance of the variability in time of such estimates. Observation-based machine learning estimates show a stronger temporal variability than model-based estimates.

scholarly journals Hazard indicators of urban soil contamination with polycyclic hydrocarbons on the example of monitoring results of the RUDN campus

2020 ◽  
Vol 28 (2) ◽  
pp. 112-130
Author(s):  
Margarita M. Redina ◽  
Alexander P. Khaustov ◽  
Xiangkai Li ◽  
Zhandos D. Kenzhin ◽  
Polina Yu. Silaeva
Keyword(s):  
Soil Contamination ◽  
Urban Areas ◽  
Carcinogenic Risk ◽  
Individual Characteristics ◽  
Forest Park ◽  
Pollution Levels ◽  
Sources Of Pollution ◽  
Functional Zones ◽  
Polycyclic Aromatic ◽  
The Individual

The characteristics of the hazard of urban soils pollution by polycyclic aromatic hydrocarbons (PAHs) are considered: naphthalene (Naph), anthracene (An), phenanthrene (Phen), pyrene (Py), fluoranthene (Flu), chrysene (Chr), benzo(a)anthracene (BaA), benzo[a]pyrene (BaP), benzo[b]fluoranthene (BbFlu), benzo[k]fluoranthene (BkFlu), dibenzo[ah]antracene (DBa), benzo[ghi]perylene (Bghi), indeno[1,2,3-c,d]pyrene). On the example of monitoring data on the RUDN University campus and the adjacent South-West Forest Park, modern approaches to assessing the hazard of pollution levels and the environmental risk of soil pollution are demonstrated: RQ indicators, total relative toxicity in comparison to BaP, carcinogenic risk, behavior of the representative PAHs. On the basis of a critical analysis of the pollution indicators, the optimal approaches to assessing the danger of the presence of polyarenes in the soils of urban areas are demonstrated. The leading sources of pollution (influence of vehicles) were identified. Different levels of environmental hazard of polyarene soil contamination in different functional zones of the analyzed territory are demonstrated: relatively clear territory in the middle zone of the park and a specific configuration of the pollution field on the rest of the territory. The necessity of developing ecosystem standards for urban natural complexes is justified, taking into account the individual characteristics of soils, the role of soil microbiota, the specificity of the use of the territory and the characteristics of pollution sources.

scholarly journals Effects of Air Pollutants on Summer Precipitation in Different Regions of Beijing

Atmosphere ◽  
2022 ◽  
Vol 13 (1) ◽  
pp. 141
Author(s):  
Yan Yang ◽  
Wei Zhou ◽  
Qian Gao ◽  
Delong Zhao ◽  
Xiange Liu ◽  
...  
Keyword(s):  
Air Pollutants ◽  
Summer Precipitation ◽  
Weather Research And Forecasting ◽  
Mountainous Areas ◽  
Cloud Droplets ◽  
Beijing Area ◽  
Pollution Levels ◽  
Mountainous Regions ◽  
Effective Particle ◽  
Air Layers

Many studies have shown that air pollutants have complex impacts on urban precipitation. Meteorological weather station and satellite Aerosol Optical Depth (AOD) product data from the last 20 years, combined with simulation results from the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem), this paper focuses on the effects of air pollutants on summer precipitation in different regions of Beijing. These results showed that air pollution intensity during the summer affected the precipitation contribution rate (PCR) of plains and mountainous regions in the Beijing area, especially in the plains. Over the past 20 years, plains PCR increased by ~10% when the AOD augmented by 0.15, whereas it decreased with lower pollution levels. In contrast, PCR in mountainous areas decreased with higher pollution levels and increased with lower pollution levels. Our analysis from model results indicated that aerosol increases reduce the effective particle size of cloud droplets and raindrops. Smaller cloud raindrops more readily transport to high air layers and participate in the generation of ice-phase substances in the clouds, increasing the total amount of cloud water in the air in a certain time, which ultimately enhanced precipitation intensity on the plains. The removal of pollutants caused by increased precipitation in the plains decreased rainfall levels in mountainous areas.

scholarly journals Size distribution and source of black carbon aerosol in urban Beijing during winter haze episodes

2016 ◽  
Author(s):  
Yunfei Wu ◽  
Xiaojia Wang ◽  
Jun Tao ◽  
Rujin Huang ◽  
Ping Tian ◽  
...  
Keyword(s):  
Size Distribution ◽  
Black Carbon ◽  
Urban Areas ◽  
Late Winter ◽  
Equivalent Diameter ◽  
Air Masses ◽  
A Value ◽  
Significant Linear Correlation ◽  
Mass Size ◽  
Black Carbon Aerosol

Abstract. Black carbon (BC) plays an important role in the climate and environment due to its light absorption, which is greatly dependent on its physicochemical properties including morphology, size and mixing state. The size distribution of the refractory BC (rBC) in urban Beijing during the late winter in 2014 was revealed by measurements obtained using a single particle soot photometer (SP2), when the hazes occurred frequently. By assuming void-free rBC with a density of 1.8 g cm−3, the mass of the rBC showed an approximately lognormal distribution as a function of the volume-equivalent diameter (VED), for which there was a peak diameter of 213 nm. This size distribution agreed well with those observed in other urban areas of China. Larger VED values of the rBC were observed during polluted periods than on clean days, implying an alteration in the rBC sources, as the mass-size of the rBC from a certain source varied little once it was emitted into the atmosphere. The potential source contribution functions showed that air masses from the south to east of the observation site brought a higher rBC loading with more thick coatings and larger core sizes. The mean VED of the rBC (VEDrBC) presented a significant linear correlation with the number fraction of thickly coated rBC (NFcoated); the VED of the entirely externally mixed rBC was inferred as the y-intercept of the linear regression. This VED, with a value of ~150 nm, was considered as the typical mean VED of the rBC from local traffic sources in this study. Accordingly, the contribution of the local traffic to the rBC was estimated based on reasonable assumptions. Local traffic contributed 35 to 100 % of the hourly rBC mass concentration with a mean of 59 %, during this campaign. A lower local traffic contribution was observed during polluted periods, suggesting increasing contributions of other sources (e.g., coal combustion/biomass burning) to the rBC. The heavy pollution in Beijing was greatly influenced by other sources in addition to the local traffic.

Pollution levels and health risk assessment of particulate phthalic acid esters in arid urban areas

2017 ◽  
Vol 8 (1) ◽  
pp. 188-195 ◽  
Author(s):  
He-Hua Zeng ◽  
Hong-Xi Zhang ◽  
Xia Wu ◽  
Hong-Xin Gu ◽  
Li-Zhong Zhang ◽  
...  
Keyword(s):  
Risk Assessment ◽  
Health Risk ◽  
Health Risk Assessment ◽  
Urban Areas ◽  
Phthalic Acid ◽  
Phthalic Acid Esters ◽  
Pollution Levels ◽  
Acid Esters

scholarly journals Measurement of Light Absorbing Aerosols with Folded-Jamin Photothermal Interferometry

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2615 ◽  
Author(s):  
Jeonghoon Lee ◽  
Hans Moosmüller
Keyword(s):  
Refractive Index ◽  
Black Carbon ◽  
Metropolitan Area ◽  
Atmospheric Aerosols ◽  
Urban Areas ◽  
Photothermal Spectroscopy ◽  
Interferometric Technique ◽  
Carbon Particles ◽  
Black Carbon Aerosol ◽  
Absorbing Aerosols

In this study, a photothermal interferometer was developed, based on a folded-Jamin polarization instrument with refractive-index sensitive configuration, in order to characterize light-absorbing aerosols. The feasibility of our interferometric technique was demonstrated by performing photothermal spectroscopy characterizing spark-generated black carbon particles with atmospherically relevant concentrations and atmospheric aerosols in a metropolitan area. The sensitivity of this interferometric system for both laboratory-generated aerosols and atmospheric aerosols was ~ 1 (μg/m3)/μV, which is sufficient for the monitoring of black carbon aerosol in urban areas.

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