Traffic aerosol emission velocity derived from direct flux measurements over urban Stockholm, Sweden
2011 (English)In: Atmospheric Environment, ISSN 1352-2310, Vol. 45, no 32, 5725-5731 p.Article in journal (Refereed) Published
Size-resolved aerosol vertical number fluxes were measured using the eddy covariance method, 105 meters above the ground over the city of Stockholm, Sweden, between 1st April 2008 and 15th April 2009. The size range of the measurements cover particles from 0.25 to 2.5 mu m diameter (D(p)). Emission velocities (ye) were calculated for the same size range and were found to be well correlated with friction velocity (U*) and CO(2) fluxes (F(CO2)). These variables were used to parameterize the emission velocity as nu(e) = (129.14(0.01D(p)(2), + 0.06D(p) + 0.008) + 1.22)u(*)F(CO2) where nu(e) and u(*) are given in [ms(-1)], Dp in [gm], and F(CO2) in [mmol m(-2)s(-1)]. The parameterization reproduces the average diurnal cycle from the observations well for particles sizes up to 0.6 mu m D(p) For larger particles the parameterization tends to over predict the emission velocity. These larger particles are not believed to be produced by combustion and therefore not well represented by F(CO2), which represents the traffic source through its fossil fuel consumption and the related CO(2) emissions.
Place, publisher, year, edition, pages
2011. Vol. 45, no 32, 5725-5731 p.
Primary aerosol emissions, Carbon dioxide emissions, Traffic aerosol, Urban aerosol, Traffic activity, Emission factors, Eddy covariance, Aerosol flux
Earth and Related Environmental Sciences
IdentifiersURN: urn:nbn:se:uu:diva-162377DOI: 10.1016/j.atmosenv.2011.07.026ISI: 000295607300009OAI: oai:DiVA.org:uu-162377DiVA: diva2:460470