Journal ArticleDOI
The influence of vehicle emission characteristics and meteorological conditions on urban no2 concentrations
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In this article, the influence of the tailpipe NO2/NOx fraction and meteorological conditions on the ambient air NO2 concentrations was investigated. But the authors focused on the road network dispersion model CAR-FMI and applied it to the analysis of the road networks.Abstract:
A major fraction of nitrogen oxides released from traffic is commonly nitrogen monoxide (NO); however, the proportion of NO2 in exhaust emissions can range from less than 1% to more than 50%. The released NO is chemically transformed into the more harmful nitrogen dioxide (NO2); the reaction time-scale is typically a few minutes in urban daylight conditions. This paper presents numerical results concerning the influence of the tailpipe NO2/NOx fraction and meteorological conditions on the ambient air NO2 concentrations. We have applied the road network dispersion model CAR-FMI in the computations.read more
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A measurement campaign in a street canyon in Helsinki and comparison of results with predictions of the OSPM model
Jaakko Kukkonen,Esko Valkonen,Jari Walden,Tarja Koskentalo,Päivi Aarnio,Ari Karppinen,Ruwim Berkowicz,Raimo Kartastenpää +7 more
TL;DR: In this paper, a measuring campaign was conducted in a street canyon (Runeberg St.) in Helsinki, where hourly mean concentrations of CO, NOx, NO2 and O3 were measured at street and roof levels, the latter in order to determine the urban background concentrations.
Journal Article
Review of urban air quality in finland
TL;DR: Measured concentrations in the largest Finnish cities and towns, presented in order of decreasing population, show no clear correlation and the results are dependent on the representativity of the location of urban monitoring stations.
Journal ArticleDOI
An Evaluation of Daumod Model in Estimating Urban Background Concentrations
TL;DR: In this article, the authors evaluated the performance of the urban atmospheric dispersion model (DAUMOD) in estimating nitrogen oxides (NOx) background concentrations in Copenhagen and found that 95.8% of hourly average estimations, 86.6% of mean daily and 100% of monthly average concentrations are within a factor of two of the observed values.
Journal ArticleDOI
The seasonal variation of urban air quality in northern European conditions
TL;DR: In this article, the seasonal variations of the guideline exceedences for CO, NO2, SO2, TSP and PM10 in urban areas in Finland are interpreted in the light of the meteorological variation.
Journal ArticleDOI
Modification of an Operational Dispersion Model for Urban Applications
TL;DR: In this article, a roughness sublayer has been introduced into the model to represent the turbulence characteristics of the lowest part of the surface layer over rough surfaces like cities, and the meteorological preprocessor was enhanced to take into account an urban energy budget.
References
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Atmospheric Chemistry and Physics of Air Pollution
TL;DR: The Gaussian Plume Equation and Air Quality Models Atmospheric Removal Processes and Residence Times Air Pollution Statistics Acid Rain Index (AIRI) as mentioned in this paper, which measures the amount of acid rain in the air.
Caline4 - a dispersion model for predicting air pollutant concentrations near roadways. final report
Journal ArticleDOI
Nitrogen dioxide in exhaust emissions from motor vehicles
TL;DR: In this paper, the NO2NOx (v/v) fractions and NO2 exhaust emission rates were determined for diesel- and gasoline-powered passenger cars and a diesel truck, at several conditions of constant engine load and speed.
Journal Article
An operational dispersion model for predicting pollution from a road
TL;DR: In this article, a mathematical model for predicting dispersion of pollution from a road, for use in a regulatory context, is presented, including an emission model, treatment of the meteorological time series, a dispersion model, statistical analysis of the computed time series of concentrations and a graphical Windows-based user interface.