Vertical distribution of aerosol particles and NOx close to a motorway

In May 2001, the large-scale field project BAB II was performed at the highly frequented motorway BAB (Bundesautobahn) A656 with two traffic lanes in each direction between the German cities Heidelberg and Mannheim. Extensive measurements of air pollutants were carried out on both sides of the motorway. In a distance of 60 m (north side) and 84 m (south side) to the traffic lanes, two 52-m-high towers were installed, at which electrically powered elevators were fixed. In these elevators, two NOx analysers, an Electrical Low Pressure Impactor (ELPI; measurement of the particle number size distribution in the diameter range 𝐷 between 30 nm and 10 μm) and a Diffusion Charger (DC; measuring the particle surface area concentration), were operated to record continuous vertical profiles from 5 to 50 m above the earth's surface. On the upwind side, particle number and surface area concentration as well as NOx values were constant over the entire height profile. On the downwind side, increased concentrations appeared in the near-ground range: in the forenoon, a monotonous decrease in pollutant concentrations with increasing height was found, while around noon the concentration maximum of the particles was slightly shifted to 10 m above ground. This height dependence was found for two different size ranges, i.e., for particles with 𝐷<300nm (consisting of soot particles and nucleation mode particles formed by condensation as a result of cooling of the exhaust gas after emission), and for coarse particles (𝐷>1μm, abrasion and resuspension products). In the size range between 300 and 700 nm, no height dependence was found, corroborating the fact that motor traffic emits only few particles in this size range. On the downwind side of the motorway, only background concentrations were measured above 25 m. The results of the profile measurements were confirmed by stationary measurements of particle size distributions with Scanning Mobility Particle Sizers (SMPS) at various heights. A good correlation between particle surface area and NOx concentration was observed. Vehicle emission factors were determined for the particle surface area, number and volume of several size ranges.

Schlagwörter

Fachgebiet (DDC)

380 - Handel, Kommunikation, Verkehr
360 - Soziale Probleme, Sozialdienste, Versicherungen

Projekt

Veranstaltung

Startdatum der Ausstellung

Enddatum der Ausstellung

Startdatum der Konferenz

Enddatum der Konferenz

Datum der letzten Prüfung

ISBN

ISSN

1352-2310
0004-6981

Sprache

Englisch

Während FHNW Zugehörigkeit erstellt

Nein

Zukunftsfelder FHNW

Publikationsstatus

Veröffentlicht

Begutachtung

Peer-Review der ganzen Publikation

Open Access-Status

Closed

Lizenz

Zitation

IMHOF, D., Ernest WEINGARTNER, Ulrich VOGT, Anja DREISEIDLER, E. ROSENBOHM, Volker SCHEER, Rainer VOGT, Ole John NIELSEN, Ralf KURTENBACH, Ulrich CORSMEIER, M. KOHLER und Urs BALTENSPERGER, 2005. Vertical distribution of aerosol particles and NOx close to a motorway. Atmospheric Environment. Oktober 2005. Bd. 39, Nr. 31, S. 5710–5721. DOI 10.1016/j.atmosenv.2004.07.036. Verfügbar unter: https://irf.fhnw.ch/handle/11654/46767

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