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

Abstract

<p><strong>Abstract.</strong> Fine-fraction aerosol samples were collected, air pollutants and meteorological properties were measured in-situ in regional background environment of the Carpathian Basin, a suburban area and central part of its largest city, Budapest in each season for 1 year-long time interval. The samples were analysed for PM<sub>2.5</sub> 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 % of the PM<sub>2.5</sub> mass with a modest seasonal variation and with a slightly increasing tendency from the regional background to the city centre (from 32 to 39 %). Coupled radiocarbon-LVG marker method was applied to apportion the total carbon (TC = OC + EC) into contributions of EC and OC from fossil fuel (FF) combustion (EC<sub>FF</sub> and OC<sub>FF</sub>, respectively), EC and OC from biomass burning (BB) (EC<sub>BB</sub> and OC<sub>BB</sub>, respectively) and OC from biogenic sources (OC<sub>BIO</sub>). Fossil fuel combustion showed rather constant daily or seasonal mean contributions (of 35 %) to the TC in the whole year in all atmospheric environments, while the daily contributions of BB and biogenic sources changed radically (from < 2 up to 70–85 %) over the seasons at all locations. In autumn, the three major sources contributed equally to the TC in all environments. In winter, it was the BB that was the major source with a share of 70 % at all sites. The contributions from biogenic sources in winter were the smallest, although they were still non-negligible with an increasing share (from 5 to 8 %) from the regional background to the urban sites. In spring, FF combustion and biogenic sources were the largest two contributors at all locations with typical shares of 45–50 % each. In summer, biogenic sources became the major source with a monotonically increasing tendency (from 56 to 72 %) from the city centre to the regional background. The share of BB was hardly quantifiable in summer. The EC<sub>FF</sub> made up more than 90 % of EC in spring and summer, while in autumn and winter, the contributions of EC<sub>BB</sub> were considerable. Biomass burning in winter and autumn offers the largest and considerable potentials for improving the air quality in cities as well as in rural areas of the Carpathian Basin.</p>

What can we learn about urban air quality with regard to the first outbreak of the COVID-19 pandemic? A case study from Central Europe

“…The strongest connections are related to cold air masses above the basin which generate a lasting T inversion and relatively shallow planetary boundary layer (cold air pool). It confirms that the daily evolution of regional meteorology can have higher influence on atmospheric concentrations than the source intensities under such conditions (Salma et al, 2020a). The curves for PM2.5 mass and N6-1000 confirmed that there is week association between these two types of aerosol metrics (de Jesus et al, 2019).…”

“…At the same time, PM10 mass represents disintegration sources, e.g. windblown or resuspended soil, crustal rock, mineral and roadside dust particularly under dry weather conditions, agricultural activities in the region and material wear (Putaud et al, 2010;Salma et al, 2020a).…”

“…The location represents a well-mixed, average atmospheric environment for the city centre due to its geographical and meteorological conditions (Salma et al, 2016a). The local emissions include diffuse urban traffic exhaust, household/residential emissions and limited industrial sources together with some off-road transport (Salma et al, 2020a). In some time intervals, long-range transport of air masses can also play a role.…”

“…These species can have multiple sources. Organic matter and elemental carbon, for instance, make up approximately 35% of the PM2.5 mass in inter (Salma et al, 2020a). Biomass burning is the major source of carbonaceous aerosol in this season with its relative contribution to total carbon of approximately 67%.…”

Influence of vegetation on occurrence and time distributions of regional new aerosol particle formation and growth

“…The typical mean contribution of biogenic sources to the total carbon in the PM2.5 size fraction was the second largest with a share of ca. 40 % (Salma et al, 2020). Unfortunately, there is no experimental information available on absolute concentrations or amounts of VOC in the area.…”