Fossil fuel combustion, biomass burning and biogenic sources of fine carbonaceous aerosol in the Carpathian Basin

• Main Authors: I. Salma, A. Vasanits-Zsigrai, A. Machon, T. Varga, I. Major, V. Gergely, M. Molnár
• Format: Article
• Language: English
• Published: Copernicus Publications 2020-04-01
• Series: Atmospheric Chemistry and Physics
• Online Access: https://www.atmos-chem-phys.net/20/4295/2020/acp-20-4295-2020.pdf
• ISSN: 1680-7316; 1680-7324

<p>Fine-fraction aerosol samples were collected, and air pollutants and meteorological properties were measured in situ in the regional background environment of the Carpathian Basin, a suburban area and central part of its largest city, Budapest, in each season for a 1-year-long time interval. The samples were analysed for PM<span class="inline-formula">_2.5</span> mass, organic carbon (OC), elemental carbon (EC), water-soluble OC (WSOC), radiocarbon, levoglucosan (LVG) and its stereoisomers, and some chemical elements. Carbonaceous aerosol species made up 36&thinsp;% of the PM<span class="inline-formula">_2.5</span> mass, with a modest seasonal variation and with a slightly increasing tendency from the regional background to the city centre (from 32&thinsp;% to 39&thinsp;%). A coupled radiocarbon-LVG marker method was applied to apportion the total carbon (TC&thinsp;<span class="inline-formula">=</span>&thinsp;OC&thinsp;<span class="inline-formula">+</span>&thinsp;EC) into contributions of EC and OC from fossil fuel (FF) combustion (EC<span class="inline-formula">_FF</span> and OC<span class="inline-formula">_FF</span>, respectively), EC and OC from biomass burning (BB) (EC<span class="inline-formula">_BB</span> and OC<span class="inline-formula">_BB</span>, respectively), and OC from biogenic sources (OC<span class="inline-formula">_BIO</span>). Fossil fuel combustion showed rather constant daily or monthly mean contributions (of 35&thinsp;%) to the TC in the whole year in all atmospheric environments, while the daily contributions of BB and biogenic sources changed radically (from <span class="inline-formula">&lt;2</span>&thinsp;% up to 70&thinsp;%–85&thinsp;%) at all locations and over the years. In October, the three major sources contributed equally to the TC in all environments. In January, it was the BB that was the major source, with a share of 70&thinsp;% at all sites. The contributions from biogenic sources in January were the smallest. In April, FF combustion and biogenic sources were the largest two contributors at all locations with typical shares of 45&thinsp;%–50&thinsp;% each. In July, biogenic sources became the major source type with a monotonically increasing tendency (from 56&thinsp;% to 72&thinsp;%) from the city centre to the regional background. The share of BB was hardly quantifiable in July. The EC<span class="inline-formula">_FF</span> made up more than 90&thinsp;% of EC in April and July, while in October and January, the contributions of EC<span class="inline-formula">_BB</span> were considerable. Biomass burning in winter and autumn offers the largest and most considerable potential for improving the air quality in cities as well as in rural areas of the Carpathian Basin.</p>