scholarly journals Seasonality in the Δ<sup>33</sup>S measured in urban aerosols highlights an additional oxidation pathway for atmospheric SO<sub>2</sub>

2019 ◽  
Vol 19 (6) ◽  
pp. 3779-3796 ◽  
Author(s):  
David Au Yang ◽  
Pierre Cartigny ◽  
Karine Desboeufs ◽  
David Widory
Keyword(s):  
Seasonal Variations ◽  
Sulfur Isotope ◽  
Mineral Dust ◽  
Monitoring Station ◽  
Urban Aerosols ◽  
Oxidation Pathway ◽  
The City ◽  
Local Emissions ◽  
Year 2013 ◽  
Monitoring Stations

Abstract. Sulfates present in urban aerosols collected worldwide usually exhibit significant non-zero Δ33S signatures (from −0.6 ‰ to 0.5 ‰) whose origin still remains unclear. To better address this issue, we recorded the seasonal variations of the multiple sulfur isotope compositions of PM10 aerosols collected over the year 2013 at five stations within the Montreal Island (Canada), each characterized by distinct types and levels of pollution. The δ34S-values (n= 155) vary from 2.0 ‰ to 11.3 ‰ (±0.2 ‰, 2σ), the Δ33S-values from −0.080 ‰ to 0.341 ‰ (±0.01 ‰, 2σ) and the Δ36S-values from −1.082 ‰ to 1.751 ‰ (±0.2 ‰, 2σ). Our study evidences a seasonality for both the δ34S and Δ33S, which can be observed either when considering all monitoring stations or, to a lesser degree, when considering them individually. Among them, the monitoring station located at the most western end of the island, upstream of local emissions, yields the lowest mean δ34S coupled to the highest mean Δ33S-values. The Δ33S-values are higher during both summer and winter, and are < 0.1 ‰ during both spring and autumn. As these higher Δ33S-values are measured in “upstream” aerosols, we conclude that the mechanism responsible for these highly positive S-MIF also occurs outside and not within the city, at odds with common assumptions. While the origin of such variability in the Δ33S-values of urban aerosols (i.e. −0.6 ‰ to 0.5 ‰) is still subject to debate, we suggest that oxidation by Criegee radicals and/or photooxidation of atmospheric SO2 in the presence of mineral dust may play a role in generating such large ranges of S-MIF.

scholarly journals Seasonality in the Δ<sup>33</sup>S measured in urban aerosols highlights an additional oxidation pathway for atmospheric SO<sub>2</sub>

2018 ◽  
Author(s):  
David Au Yang ◽  
Pierre Cartigny ◽  
Karine Desboeufs ◽  
David Wîdory
Keyword(s):  
Seasonal Variations ◽  
Sulfur Isotope ◽  
Monitoring Station ◽  
Urban Aerosols ◽  
Oxidation Pathway ◽  
Local Emissions ◽  
Year 2013 ◽  
Monitoring Stations

Abstract. Sulfates present in urban aerosols collected worldwide usually exhibit significant non-zero Δ33S signatures (from −0.6 to 0.5 ‰) whose origin still remains unclear. To better address this issue, we recorded the seasonal variations of the multiple sulfur isotope compositions of PM10 aerosols collected over the year 2013 at five stations within the Montreal Island (Canada), each characterized by distinct types and levels of pollution. The δ34S-values (n = 155) vary from 2.0 to 11.3 ‰ (± 0.2 ‰, 2σ), the Δ33S-values from −0.080 to 0.341 ‰ (± 0.01 ‰, 2σ) and the Δ36S-values from −1.082 to 1.751 ‰ (± 0.2 ‰, 2σ). Our study evidences a seasonality for both the δ34S and Δ33S, which can be observed either when considering all monitoring stations or, to a lesser degree, when considering them individually. Among them, the monitoring station located at the most western end of the island, upstream of local emissions, yields the lowest mean δ34S coupled to the highest mean Δ33S-values. The Δ33S-values are higher during both summer and winter, and are

scholarly journals Representativeness of monitoring station readings in the context of urban environment

2021 ◽  
Vol 2057 (1) ◽  
pp. 012132
Author(s):  
V D Meshkova ◽  
A A Dekterev ◽  
K Yu Litvintsev
Keyword(s):  
Wind Speed ◽  
Urban Environment ◽  
Meteorological Parameters ◽  
Numerical Study ◽  
Comprehensive Analysis ◽  
Monitoring Station ◽  
Complex Mechanism ◽  
The City ◽  
Different Parts ◽  
Monitoring Stations

Abstract In this paper, a comprehensive analysis of the interaction of the urban environment elements with the natural environment components is carried out. The assessment of the complex impact of meteorological parameters on the human body is analyzed based on data obtained from monitoring stations. The readings of monitoring stations concerning both wind speed and directions are found to significantly deviate in different parts of the city due to urban development. A numerical study of the neighborhood with the monitoring station also shows a very complex mechanism for determining the pollution intensity of the area and the relevance of the data obtained, especially concerning pollutants.

scholarly journals Cascade Feed Forward Neural Network-based Model for Air Pollutants Evaluation of Single Monitoring Stations in Urban Areas

2015 ◽  
Vol 61 (4) ◽  
pp. 327-332 ◽  
Author(s):  
Giacomo Capizzi ◽  
Grazia Lo Sciuto ◽  
P. Monforte ◽  
Christian Napoli
Keyword(s):  
Neural Network ◽  
Urban Areas ◽  
Air Pollutants ◽  
Monitoring Station ◽  
Feed Forward Neural Network ◽  
Feed Forward ◽  
The City ◽  
Monitoring Stations

Abstract In this paper, air pollutants concentrations for NO2, NO, NOx and PM10 in a single monitoring station are predicted using the data coming from other different monitoring stations located nearby. A cascade feed forward neural network based modeling is proposed. The main aim is to provide a methodology leading to the introduction of virtual monitoring station points consistent with the actual stations located in the city of Catania in Italy

scholarly journals Statistical modeling of particle mater air pollutants in the city of Ruse, Bulgaria

2018 ◽  
Vol 145 ◽  
pp. 01010 ◽  
Author(s):  
Evelina Veleva ◽  
Ivanka Zheleva
Keyword(s):  
Air Pollution ◽  
Statistical Analysis ◽  
Statistical Modeling ◽  
Air Pollutants ◽  
Air Pollutant ◽  
Monitoring Station ◽  
Pm10 And Pm2.5 ◽  
Using Data ◽  
The City ◽  
Monitoring Stations

This paper is devoted to examine the PM10 and PM2.5 pollution in Ruse region, Bulgaria. It is a continuation of our previous work [1] where we presented a statistical analysis and modelling of the level of PM10 air pollution in Ruse using data from one of two monitoring stations (station 2) in the city. Now in this paper we present statistical analysis of the level of PM10 pollutant on the basis of data from the another monitoring station (station 1). The measurements cover the period since 2015 up to now. The results from analysis and modelling of PM2.5 air pollutant are also presented and commented in the paper.

Influence of mineral dust on the concentration and composition of PM10 in the city of Constantine

2021 ◽  
Vol 50 ◽  
pp. 100677
Author(s):  
Kanza Lokorai ◽  
Hocine Ali-Khodja ◽  
Salah Khardi ◽  
Fairouz Bencharif-Madani ◽  
Lamri Naidja ◽  
...  
Keyword(s):  
Mineral Dust ◽  
The City

Seasonal variations of elemental carbon in urban aerosols as measured by two common thermal-optical carbon methods

2009 ◽  
Vol 407 (18) ◽  
pp. 5176-5183 ◽  
Author(s):  
Min-Suk Bae ◽  
James J. Schauer ◽  
Jay R. Turner ◽  
Philip K. Hopke
Keyword(s):  
Seasonal Variations ◽  
Elemental Carbon ◽  
Urban Aerosols

scholarly journals Radiocarbon in the Air of Central Europe: Long-Term Investigations

Radiocarbon ◽  
2010 ◽  
Vol 52 (2) ◽  
pp. 823-834 ◽  
Author(s):  
I Svetlik ◽  
P P Povinec ◽  
M Molnár ◽  
M Vána ◽  
A Šivo ◽  
...  
Keyword(s):  
Central Europe ◽  
Monitoring Station ◽  
High Mountain ◽  
The Czech Republic ◽  
Suess Effect ◽  
Clean Air ◽  
Low Altitude ◽  
The Impact ◽  
Monitoring Stations

Regional levels of radiocarbon have been monitored in order to investigate the impact of fossil fuel combustion on the activity of atmospheric 14CO2 in central Europe. Data from atmospheric 14CO2 monitoring stations in the Czech Republic, Slovakia, and Hungary for the period 2000–2008 are presented and discussed. The Prague and Bratislava monitoring stations showed a distinct local Suess effect when compared to the Jungfraujoch clean-air monitoring station. However, during the summer period, statistically insignificant differences were observed between the low-altitude stations and the high-mountain Jungfraujoch station. 14C data from the Hungarian monitoring locality at Dunaföldvár and the Czech monitoring station at Košetice, which are not strongly affected by local fossil CO2 sources, indicate similar grouping and amplitudes, typical for a regional Suess effect.

scholarly journals Seasonal Variations of Pollinator Assemblages among Urban and Rural Habitats: A Comparative Approach Using a Standardized Plant Community

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 199
Author(s):  
Vincent Zaninotto ◽  
Adrien Perrard ◽  
Olivier Babiar ◽  
Amandine Hansart ◽  
Cécile Hignard ◽  
...  
Keyword(s):  
Seasonal Variations ◽  
Urban Environments ◽  
Green Spaces ◽  
Comparative Approach ◽  
Wild Bees ◽  
Generalist Species ◽  
Urban Green Spaces ◽  
Natural Grasslands ◽  
Insect Pollinators ◽  
The City

Even though urban green spaces may host a relatively high diversity of wild bees, urban environments impact the pollinator taxonomic and functional diversity in a way that is still misunderstood. Here, we provide an assessment of the taxonomic and functional composition of pollinator assemblages and their response to urbanization in the Paris region (France). We performed a spring-to-fall survey of insect pollinators in green spaces embedded in a dense urban matrix and in rural grasslands, using a plant setup standardized across sites and throughout the seasons. We compared pollinator species composition and the occurrence of bee functional traits over the two habitats. There was no difference in species richness between habitats, though urban assemblages were dominated by very abundant generalist species and displayed a lower evenness. They also included fewer brood parasitic, solitary or ground-nesting bees. Overall, bees tended to be larger in the city than in the semi-natural grasslands, and this trait exhibited seasonal variations. The urban environment filters out some life history traits of insect pollinators and alters their seasonal patterns, likely as a result of the fragmentation and scarcity of feeding and nesting resources. This could have repercussions on pollination networks and the efficiency of the pollination function.

Simulation model of scattering properties and extinction of laser light applied to urban aerosols over the city of Cali, Colombia

2005 ◽  
Author(s):  
Edith Rodríguez ◽  
Elena Montilla ◽  
Mauricio Jaramillo ◽  
Efraín Solarte ◽  
Alvaro Bastidas
Keyword(s):  
Simulation Model ◽  
Laser Light ◽  
Urban Aerosols ◽  
The City
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