Three years of size-resolved eddy-covariance particle number flux measurements in Berlin, Germany

Please contact the authors Agnes Straaten (agnes.straaten@tu-braunschweig.de) or Stephan Weber (s.weber@tu-braunschweig.de) to make a request for the research data.

Size-resolved particle number fluxes in the size range 10 nm < particle diameter (D_p) < 200 nm were measured over a 3-year period (April 2017 - March 2020) using the eddy covariance technique at an urban site in Berlin, Germany. The observations indicated the site as a net source of particles with a median total particle number flux of F_TNC = 0.86 x 10⁸ m^-2 s^-1. The turbulent surface-atmosphere exchange of particles was clearly dominated by ultrafine particles (D_p < 100 nm) with a share of 96 % of total particle number flux (F_UFP = 0.83 x 10⁸ m^-2 s^-1). Annual estimates of median F_TNC and F_UFP slightly decreased by - 9.6 % (- 8.9 % for F_UFP) from the first to the second observation year and a further - 5.9 % (- 6.1 % for F_UFP) from the second to the third year. The annual variation might be due to different reasons such as variation of flux footprints in the individual years, a slight reduction of traffic intensity in the third year or progressive transition of the vehicle fleet towards a higher share of low-emission standards or electric drive. Size resolved measurements illustrated events of bidirectional fluxes, i.e. simultaneous emission and deposition fluxes within the size spectrum, which occurred more often in spring, late summer and autumn than in winter. Multi-year observations of size-resolved particle fluxes proved to be important for deeper understanding of particle exchange processes with the urban surface and the pronounced influence of traffic at this urban site. 

This dataset provides the presented data in the below mentioned research article Straaten & Weber (2021). For further details please take a look into that article.