Evaluation of the NO2 burden within a joint street canyon and tunnel portal micro environment
- Resource Type
- Authors
- Ulrich Uhrner; Peter-Johann Sturm; Raphael Jakob Reifeltshammer
- Source
- International Journal of Environment and Pollution. 65:25
- Subject
- Turbulent mixing
Meteorology
Flow (psychology)
Management, Monitoring, Policy and Law
Pollution
Wind speed
symbols.namesake
Micro environment
symbols
Environmental science
Diffusion (business)
Joint (geology)
Waste Management and Disposal
Lagrangian
Street canyon
- Language
- ISSN
- 1741-5101
0957-4352
Substantial breaches in NO2 limits in the vicinity of a tunnel portal and street canyon micro environment provided the motivation for this paper. The impact of portal and surface road emissions was assessed and mitigation scenarios computed, in order to aid the authorities responsible. Emphasis was placed on detailed emission processing. A unique data set from nine NO2 monitors located near the portal and within the street canyon was used to evaluate the model approach using a Lagrangian particle model. Good agreement with measurements was obtained using simple NOx/NO2 conversion approaches. The NOx/NO2 concentration pattern is dominated by surface road emissions. A kerbside area of ~30 m in the driving direction is clearly dominated by the portal emissions indicating effective diffusion at the portal. Major uncertainties are related to the interaction of flow and turbulent mixing from ambient atmospheric conditions and traffic, particularly at low wind speed conditions.