Preprints
https://doi.org/10.5194/acp-2021-516
https://doi.org/10.5194/acp-2021-516

  14 Jul 2021

14 Jul 2021

Review status: this preprint is currently under review for the journal ACP.

Chemically speciated mass size distribution, particle effective density and origin of non-refractory PM1 measured at a rural background site in Central Europe

Petra Pokorná1, Naděžda Zíková1, Radek Lhotka1,2, Petr Vodička1, Saliou Mbengue3, Adéla Holubová Šmejkalová4, Véronique Riffault5, Jakub Ondráček1, Jaroslav Schwarz1, and Vladimír Ždímal1 Petra Pokorná et al.
  • 1Department of Aerosol Chemistry and Physics, Institute of Chemical Process Fundamentals, Czech Academy of Sciences, Rozvojová 135/1, 165 02 Prague, Czech Republic
  • 2Institute for Environmental Studies, Faculty of Science, Charles University, Benátská 2, 128 01 Prague 2, Czech Republic
  • 3Global Change Research Institute, Czech Academy of Sciences, Bělidla 986/4a, 603 00 Brno, Czech Republic
  • 4Czech Hydrometeorological Institute, Air Quality Division, Na Šabatce 2050/17, 143 06 Prague, Czech Republic
  • 5IMT Lille Douai, Institut Mines-Télécom, Université de Lille, Centre for Energy and Environment, F-59000 Lille, France

Abstract. The seasonal variability of non-refractory PM1 (NR-PM1) was studied at a rural background site (National Atmospheric Observatory Košetice – NAOK) in the Czech Republic to examine the impact of atmospheric regional and long-range transport in Central Europe. NR-PM1 measurements were performed by compact time-of-flight aerosol mass spectrometry (C-ToF-AMS), and the chemically speciated mass size distributions, effective density, and origin were discussed. The average PM1 concentrations, calculated as the sum of the NR-PM1 (after collection efficiency corrections – CE corrections of 0.4 and 0.33 in summer and winter, respectively) and the equivalent black carbon (eBC) concentrations measured by an aethalometer (AE), were 8.58 ± 3.70 μg m−3 in summer and 10.08 ± 8.04 μg m−3 in winter. Organics dominated during both campaigns (summer/winter: 4.97 ± 2.92/4.55 ± 4.40 μg m−3), followed by sulphate in summer (1.68 ± 0.81/1.36± 1.38 μg m−3) and nitrate in winter (0.67 ± 0.38/2.03 ± 1.71 μg m−3). The accumulation mode dominated the average mass size distribution during both seasons, with larger particles of all species measured in winter (mode diameters: Org: 334/413 nm, NO3: 377/501 nm, SO42−: 400/547 nm, and NH4+: 489/515 nm) pointing to regional and long-range transport. However, since the winter aerosols were less oxidized than the summer aerosols (comparing fragments f44 and f43), the importance of local sources in the cold part of the year was not negligible. The average PM1 particle effective density, defined as the ratio of the mass to the volume of a particle, corresponded to higher inorganic contents during both seasons (summer: ∼ 1.30 g cm−3 and winter: ∼ 1.40 g cm−3). However, the effective densities during episodes of higher mass concentrations calculated based on the particle number (mobility diameter) and mass size distribution (vacuum aerodynamic diameter) were even higher, ranging from 1.40–1.60 g cm−3 in summer and from 1.40–1.75 g cm−3 in winter. Although aged continental air masses from the SE were rare in summer (7 %), they were connected with the highest concentrations of all NR-PM1 species, especially sulphate and ammonium. In winter, slow continental air masses from the SW (44 %) were linked to inversion conditions over Central Europe and were associated with the highest concentrations among all NR-PM1 measurements.

Petra Pokorná et al.

Status: open (extended)

Comment types: AC – author | RC – referee | CC – community | EC – editor | CEC – chief editor | : Report abuse
  • RC1: 'Comment on acp-2021-516', Anonymous Referee #1, 10 Aug 2021 reply

Petra Pokorná et al.

Petra Pokorná et al.

Viewed

Total article views: 308 (including HTML, PDF, and XML)
HTML PDF XML Total BibTeX EndNote
241 61 6 308 0 0
  • HTML: 241
  • PDF: 61
  • XML: 6
  • Total: 308
  • BibTeX: 0
  • EndNote: 0
Views and downloads (calculated since 14 Jul 2021)
Cumulative views and downloads (calculated since 14 Jul 2021)

Viewed (geographical distribution)

Total article views: 312 (including HTML, PDF, and XML) Thereof 312 with geography defined and 0 with unknown origin.
Country # Views %
  • 1
1
 
 
 
 
Latest update: 23 Oct 2021
Download
Short summary
The accumulation mode dominated the average mass size distributions, with larger particles of NR-PM1 species in winter linked to seasonally differentiated regional and long-range origins, as well as to the variability in the local sources primarily observed in winter. Comparison of spectra fitting and chemical-based particle density calculations revealed differences in these two approaches due to the presence of unknown compounds, particle physical characteristics and calculation uncertainties.
Altmetrics