Comparison of the predictions of two road dust emission models with the measurements of a mobile van

M Kauhaniemi,A Karppinen,A Stojiljkovic,G Omstedt,B R Denby,J Härkönen,L Kangas,L Pirjola,J Kukkonen,K Kupiainen,M A Aarnio

doi:10.5194/acp-14-9155-2014

Abstract

Abstract. The predictions of two road dust suspension emission models were compared with the on-site mobile measurements of suspension emission factors. Such a quantitative comparison has not previously been reported in the reviewed literature. The models used were the Nordic collaboration model NORTRIP (NOn-exhaust Road TRaffic Induced Particle emissions) and the Swedish–Finnish FORE model (Forecasting Of Road dust Emissions). These models describe particulate matter generated by the wear of road surface due to traction control methods and processes that control the suspension of road dust particles into the air. An experimental measurement campaign was conducted using a mobile laboratory called SNIFFER, along two selected road segments in central Helsinki in 2007 and 2008. The suspended PM10 concentration was measured behind the left rear tyre and the street background PM10 concentration in front of the van. Both models reproduced the measured seasonal variation of suspension emission factors fairly well during both years at both measurement sites. However, both models substantially under-predicted the measured emission values. The article illustrates the challenges in conducting road suspension measurements in densely trafficked urban conditions, and the numerous requirements for input data that are needed for accurately applying road suspension emission models.

Highlights

Fine particles primarily originate from combustion sources, whereas coarse particles are produced mechanically by construction activities, windblown suspension (WHO, 2005), and the wear of road surface and vehicle components (e.g. Kupiainen, 2007)
The modelled values for both the emission factors for all traffic and for a van were compared against the measured suspension emission factors
The maximum PM10 concentrations and suspension emission factors in Helsinki have most commonly been measured in the later part of March and early part of April, the year-to-year variation has been found to be substantial (Kukkonen et al, 1999, 2000; Kupiainen et al, 2009)

Summary

Introduction

Fine particles primarily originate from combustion sources, whereas coarse particles are produced mechanically by construction activities, windblown suspension (WHO, 2005), and the wear of road surface and vehicle components (e.g. Kupiainen, 2007). Fine particles primarily originate from combustion sources, whereas coarse particles are produced mechanically by construction activities, windblown suspension (WHO, 2005), and the wear of road surface and vehicle components Development and regulations regarding car engines and exhaust cleaning systems during the last decade have resulted in a significant decrease of exhaust particulate emissions of vehicular traffic in the European Union. The improved engine and exhaust cleaning techniques have had practically no effect on the non-exhaust vehicular emissions. The relative contribution of non-exhaust particulate emissions is increasing, and should be assessed quantitatively (e.g. Keuken, 2006). The contribution of non-exhaust emissions has commonly been studied by performing stationary field measurements of particle mass-based concentrations at various urban traffic sites. The fractions of various emission source categories can be quantified, by source apportionment (e.g. AbuAllaban et al, 2003) or statistical analyses The fractions of various emission source categories can be quantified, by source apportionment (e.g. AbuAllaban et al, 2003) or statistical analyses (e.g. Bukowiecki et al, 2010)

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