Remember Me
Or use your Academic/Social account:


Or use your Academic/Social account:


You have just completed your registration at OpenAire.

Before you can login to the site, you will need to activate your account. An e-mail will be sent to you with the proper instructions.


Please note that this site is currently undergoing Beta testing.
Any new content you create is not guaranteed to be present to the final version of the site upon release.

Thank you for your patience,
OpenAire Dev Team.

Close This Message


Verify Password:
Verify E-mail:
*All Fields Are Required.
Please Verify You Are Human:
fbtwitterlinkedinvimeoflicker grey 14rssslideshare1
Ripamonti, Giovanna; Jarvi, Leena; Molgaard, Bjarke; Hussein, Tareq; Nordbo, Annika; Hameri, Kaarle (2013)
Publisher: Tellus B
Journal: Tellus B
Languages: English
Types: Article
Subjects: Meteorology. Climatology, AREA, EUROPEAN CITIES, 114 Physical sciences, Particle number size distribution, Cluster analysis; Eddy covariance; Particle fluxes; Vehicle emission factor, particle number size distribution, FINE PARTICLES, eddy covariance, SURFACE-ATMOSPHERE INTERACTIONS, QC851-999, particle fluxes, vehicle emission factor, ULTRAFINE PARTICLES, CLUSTER-ANALYSIS, PARTICULATE AIR-POLLUTION, STATISTICAL-ANALYSIS, EMISSION FACTORS, atmospheric physics; aerosol science, URBAN-ENVIRONMENT
Three years of aerosol particle number concentrations (PNCs), size distributions and vertical particle fluxes measured at the semi-urban SMEAR III station in Helsinki, Finland, were studied. The purpose is to study the local emission sources and their effect on particle concentrations and size distributions. By means of cluster analysis, six representative size distributions were identified. Their occurrence together with particle concentrations and fluxes were found to vary significantly with wind direction. Lower particle concentrations and fluxes were measured downwind from vegetated and residential areas compared to directions where the measurement site is downwind from roads passing near the measurement site. For these directions, contributions of the local sources on the measured particle concentrations and size distributions were evident. In particular, size distributions with a mode in the size range 2040 nm were found to be more affected by local traffic emissions, whereas the mode shifted towards larger sizes when contribution from distant sources was more evident. Using flux footprint functions, mixed vehicle fleet emission factors (EFs) were derived from the particle flux measurements. EFs of 6.03(±0.19)∙1014 # Veh-1 km-1 and 3.65(±0.12) ∙1014 # Veh-1 km-1 were estimated for cold (October to March) and warm (April to September) periods, respectively. Emission factors increased with decreasing air temperature (T) following a linear relationship EF = -0.20∙1014 # Veh-1 km-1 °C-1T+ 6.98∙1014# Veh-1 km-1 (RMSE = 3.7∙1014 # Veh-1 km-1).Keywords: particle number size distribution, eddy covariance, particle fluxes, vehicle emission factor(Published: 28 June 2013Citation: Tellus B 2013, 65, 19786, http://dx.doi.org/10.3402/tellusb.v65i0.19786 

Share - Bookmark

Cite this article