Articles | Volume 16, issue 17
Research article
13 Sep 2016
Research article |  | 13 Sep 2016

Seasonal variation of atmospheric particle number concentrations, new particle formation and atmospheric oxidation capacity at the high Arctic site Villum Research Station, Station Nord

Quynh T. Nguyen, Marianne Glasius, Lise L. Sørensen, Bjarne Jensen, Henrik Skov, Wolfram Birmili, Alfred Wiedensohler, Adam Kristensson, Jacob K. Nøjgaard, and Andreas Massling

Abstract. This work presents an analysis of the physical properties of sub-micrometer aerosol particles measured at the high Arctic site Villum Research Station, Station Nord (VRS), northeast Greenland, between July 2010 and February 2013. The study focuses on particle number concentrations, particle number size distributions and the occurrence of new particle formation (NPF) events and their seasonality in the high Arctic, where observations and characterization of such aerosol particle properties and corresponding events are rare and understanding of related processes is lacking.

A clear accumulation mode was observed during the darker months from October until mid-May, which became considerably more pronounced during the prominent Arctic haze months from March to mid-May. In contrast, nucleation- and Aitken-mode particles were predominantly observed during the summer months. Analysis of wind direction and wind speed indicated possible contributions of marine sources from the easterly side of the station to the observed summertime particle number concentrations, while southwesterly to westerly winds dominated during the darker months. NPF events lasting from hours to days were mostly observed from June until August, with fewer events observed during the months with less sunlight, i.e., March, April, September and October. The results tend to indicate that ozone (O3) might be weakly anti-correlated with particle number concentrations of the nucleation-mode range (10–30 nm) in almost half of the NPF events, while no positive correlation was observed. Calculations of air mass back trajectories using the Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model for the NPF event days suggested that the onset or interruption of events could possibly be explained by changes in air mass origin. A map of event occurrence probability was computed, indicating that southerly air masses from over the Greenland Sea were more likely linked to those events.

Short summary
Aerosol particles strongly influence climate change as they can absorb or reflect solar radiation. This work investigates aerosol particles in the remote northern Arctic. "Newly born" particles are small, then they "age" and grow in size due to different mechanisms. The results showed that during the polar night and especially Arctic spring, particles were likely transported from longer distances and were aged. During summer, "younger" particles are observed, which might be linked to ozone.
Final-revised paper