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

doi:10.5194/acp-16-11319-2016

Abstract

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.

Highlights

Climate change driven by anthropogenic greenhouse gas emissions is a global challenge
The observed new particle formation (NPF) events at the station lasted from hours to days with various onset times
O3 was possibly related to the observed NPF events, with 46 % of NPF cases showing a weak to moderate anti-correlation between O3 concentration and integrated particle number concentrations for the nucleationmode range (10–30 nm), while no positive correlation was found, and the remainder of events showed no correlation

Summary

Introduction

Climate change driven by anthropogenic greenhouse gas emissions is a global challenge. Nguyen et al.: Seasonal variation of atmospheric particle number concentrations tion of the Earth’s albedo due to ice loss subsequently impacts the radiative balance of the Earth through a positive feedback, leading to further warming. The Arctic has been considered a manifestation of global warming with the rate of temperature increase in the region being twice as high as the rest of the world (IPCC, 2013; ACIA, 2005), up to 8–9 ◦C along the east coast of Greenland (Stendel et al, 2008). In addition to long-lived greenhouse gases, short-lived climate forcers including tropospheric ozone, aerosols and black carbon play a significant role in affecting the radiative balance in the Arctic (Quinn et al, 2008; Bond et al, 2013; IPCC, 2013)

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