Atmospheric Chemistry and Physics | 2019
Biogenic and anthropogenic sources of aerosols at the High Arctic site Villum Research Station
Abstract
Abstract. There are limited measurements of the chemical\ncomposition, abundance and sources of atmospheric particles in the High\nArctic To address this, we report 93\u2009d of soot particle aerosol mass\nspectrometer (SP-AMS) data collected from 20\xa0February to 23\xa0May\n2015 at Villum Research Station (VRS) in northern Greenland\n(81 ∘ 36 ′ \u2009N). During this period, we observed the Arctic haze\nphenomenon with elevated PM1 concentrations ranging from an average of\n2.3, 2.3 and 3.3\u2009 µ g\u2009m −3 in February, March and April, respectively, to 1.2\u2009 µ g\u2009m −3 in May. Particulate sulfate ( SO 4 2 - ) accounted\nfor 66\u2009% of the non-refractory PM1 with the highest concentration until\nthe end of April and decreasing in May. The second most abundant species was\norganic aerosol (OA) (24\u2009%). Both OA and PM1 , estimated from the sum\nof all collected species, showed a marked decrease throughout May in\naccordance with the polar front moving north, together with changes in\naerosol removal processes. The highest refractory black carbon (rBC)\nconcentrations were found in the first month of the campaign, averaging 0.2\u2009 µ g\u2009m −3 . In March and April, rBC averaged 0.1\u2009 µ g\u2009m −3 while decreasing to 0.02\u2009 µ g\u2009m −3 in May. Positive matrix factorization (PMF) of the OA mass spectra yielded three\nfactors: (1)\xa0a hydrocarbon-like organic aerosol (HOA) factor, which was\ndominated by primary aerosols and accounted for 12\u2009% of OA mass, (2)\xa0an\nArctic haze organic aerosol (AOA) factor and (3)\xa0a more oxygenated marine\norganic aerosol (MOA) factor. AOA dominated until mid-April (64\u2009%–81\u2009%\nof OA), while being nearly absent from the end of May and correlated\nsignificantly with SO 4 2 - , suggesting the main part of that factor\nis secondary OA. The MOA emerged late at the end of March, where it\nincreased with solar radiation and reduced sea ice extent and dominated OA\nfor the rest of the campaign until the end of May (24\u2009%–74\u2009% of OA), while\nAOA was nearly absent. The highest O∕C ratio (0.95) and S∕C ratio (0.011)\nwas found for MOA. Our data support the current understanding that Arctic\naerosols are highly influenced by secondary aerosol formation and receives an\nimportant contribution from marine emissions during Arctic spring in remote\nHigh Arctic areas. In view of a changing Arctic climate with changing\nsea-ice extent, biogenic processes and corresponding source strengths,\nhighly time-resolved data are needed in order to elucidate the components\ndominating aerosol concentrations and enhance the understanding of the\nprocesses taking place.