Characterization of distinct Arctic Aerosol Accumulation Modes and their Sources

Research output: Contribution to journalArticle

Authors

  • R. Lange
  • Manuel Dall'Osto
  • H. Skov
  • I.E. Nielsen
  • R. Simo
  • A. Massling

Colleges, School and Institutes

External organisations

  • Department of Environmental Science, Aarhus University, Frederiksborgvej 399, 4000, Roskilde, Denmark
  • Department of Environmental Sciences / Center of Excellence in Environmental Studies, King Abdulaziz University, PO Box 80203, Jeddah, 21589, Saudi Arabia
  • Institute of Marine Sciences, ICM-CSIC, Passeig Marítim de la Barceloneta, 37-49. E-08003, Barcelona, Spain
  • CSIC

Abstract

Measurements of aerosol number size distributions (9-915 nm), as well as aerosol chemistry and cloud condensation nuclei (CCN) activity, were undertaken at Villum Research Station, Station Nord (VRS) in North Greenland during a 7 year record (2010-2016). Clustering analysis on daily size distributions identified several k-means SMPS clusters. K-means clusters of accumulation aerosols (with main size modes >100 nm) accounted for 56% of the total aerosol time sampling period (89-91% during February-April, 1-3% during June-August). By air trajectory association, diurnal variation patterns, and relationship to meteorological and pollution variables, three typical accumulation-mode aerosol categories were identified: Haze (32% of the time), Bimodal (14%) and Aged (6%). In brief: (1) Haze accumulation aerosol shows a single mode at 150 nm, peaking in February-April, with highest loadings of sulfate and black carbon concentrations; (2) Aged accumulation aerosol shows a single mode at 213 nm, peaking in September-October and is associated with cloudy and humid weather conditions during autumn; and (3) Accumulation Bimodal aerosol shows two modes at 38 nm and 150 nm, peaking in June-August, with the highest ratio of organics to sulfate concentrations. The three aerosol categories were considered alongside Cloud Condensation Nuclei (CCN) concentrations. We suggest that organic compounds - likely biogenic in nature and responsible for the smaller mode in the Bimodal category - contribute significantly to the CCN activity. It is concluded that - at least during summer - an Aitken mode, biogenic in origin always coexists with an accumulation mode, stressing the importance of better characterizing the marine ecosystem and the aerosol-mediated climate effects in the Arctic.

Details

Original languageEnglish
Pages (from-to)1-10
JournalAtmospheric Environment
Volume183
Early online date29 Mar 2018
Publication statusE-pub ahead of print - 29 Mar 2018

Keywords

  • Arctic aerosol, Cluster analysis, Accumulation mode, CCN, Biogenic aerosol