Source apportionment of fine aerosol at a rural background site in Central Europe based on seasonal distributions of dicarboxylic acids, sugars and related compounds

Water-soluble dicarboxylic acids (hereafter diacids) and sugars are an important part of the atmospheric water-soluble organic aerosol. Here, we studied diacids and other compounds in fine aerosol particles (PM₁) collected at a rural background site National Atmospheric Observatory Košetice (NAOK), Czech Republic, Central Europe. Aerosol samples were collected every second day for 24 h from September 2013 to August 2014 (n=146). Based on receptor modeling (PMF), we identified PM₁ organic compounds that are more typical to anthropogenic and to biogenic sources. We have apportioned two anthropogenic sources especially evident during the heating season from mid-October to mid-April: (i) biomass burning (BB) (main contribution of levoglucosan and methylsuccinic, maleic, methylmaleic and azelaic acids) and (ii) fossil fuel combustion (FF) (represented by phthalic, terephthalic and ketomalonic acids). Furthermore, we identified two sources of biogenic aerosols: (iii) summer factor was largely characterized by compounds with three and seven carbons (malonic, 4-ketopimelic, oxoheptanoic, methylmalonic acids) while (iv) spring biogenic factor was characterized mostly by primary sugars, normal chain diacids and their precursors (oxalic, malonic, succinic, glutaric, ketomalonic, 4-oxobutanoic and 5-oxopentanoic acids). Last but not least, we distinguished (v) background factor mainly represented by less oxidized diacids precursors such as glyoxal, methylglyoxal, glyoxylic and pyruvic acids, but also by aromatic diacids, which may originate from traffic emissions; a stable and year-round source.

Acknowledgement: This conference contribution was supported by the Ministry of Education, Youth and Sports of the Czech Republic under the project ACTRIS-CZ-LM2018122, by the Czech Science Foundation grant No. 20–08304J and by the Japan Society for the Promotion of Science (JSPS) through Grant-in-Aid No. 24221001. We appreciate the financial support of JSPS fellowship to P. Vodička (P16760) in Japan.

Reference: Vodička, P., Kawamura, K., Deshmukh, D.K., Pokorná, P., Schwarz, J., Ždímal, V.: Anthropogenic and biogenic tracers of fine aerosol based on seasonal distributions of dicarboxylic acids, sugars and related compounds at a rural background site in Central Europe, Atmos. Environ., submitted, 2023.