One-Year-Long Continuous and Synchronous Data Set of Fossil Carbon in Atmospheric PM_2.5 and Carbon Dioxide in Debrecen, Hungary

Abstract

ABSTRACT. Radiocarbon investigation of atmospheric PM 2.5 aerosol synchronized with 14 CO 2 observations began in Debrecen in the winter of 2010. The aim of the study was to determine the contemporary and fossil carbon fractions in the aerosol and to set them against the fossil CO 2 excess data referring to the same period. The mass of the collected PM 2.5 mode on prebaked quartz filters was determined gravimetrically, while its total carbon mass was calculated from the pressure of CO 2 gas produced after the combustion of the filters. As a result of the applied sampling and preparation method, the stable, nonvolatile carbon forms were principally studied.14 C measurements of the tiny aerosol bulk samples were performed using the EnvironMICADAS accelerator mass spectrometer at ATOMKI. The sample preparation method was tested using several blanks, standards, and real samples. Test results showed good reproducibility for the applied aerosol sample preparation and accelerator mass spectrometry (AMS) 14 C analyses. Atmospheric fossil CO 2 excess data were calculated according Levin et al. (2003), using the 14 C results of collected CO 2 samples measured by the gas proportional counting system at ATOMKI. Mass concentration of PM 10 involving the PM 2.5 mode in the city air exceeded the daily average of 50 µg/m 3 (24-hr limit value in the EU) several times in 2011, mainly during the winter. The results showed that recently derived carbon most likely from domestic wood burning was causing the elevated carbon mass concentration of PM 2.5 in Debrecen at the time. In the course of the 1-yr-long continuous and systematic comparison of fossil carbon mass concentration of PM 2.5 mode and mole fraction of fossil excess of atmospheric CO 2 , similar and synchronous trends were observed during the studied period in Debrecen.

Fossil Carbon Load in Urban Vegetation for Debrecen, Hungary

“…Due to the bomb 14 C, the biomass that has grown since the 1950s, has slightly higher specific 14 C activity than the modern atmospheric CO 2 of the respective years. This effect has already been observed and described in other studies dealing with 14 C measurements of carbonaceous aerosols (Heal et al 2011;Major et al 2015). In the case of sampling points no.…”

“…In addition, 13 samples were collected close to each other in the courtyard of the Hertelendi Laboratory (Table 2) within a 50-m circle around a 14 CO 2 atmopsheric monitoring station (47.5427N, 21.6237E, 3 m a.g.l), where the local urban atmospheric CO 2 has been sampled since 2008 (Molnár et al 2010a). This backyard is a minimum of 50 m away from busy roads and intensive industrial activity (Molnár et al 2010b;Major et al 2015). In this way, it is possible to compare the 14 C signals in plants during the vegetation period (March-September) to each other and to the local atmospheric 14 CO 2 data taken as background.…”

Detailed Carbon Isotope Study of PM2.5 Aerosols at Urban Background, Suburban Background and Regional Background Sites in Hungary

“…Among the most relevant atmospheric research in the region, Gelencsér et al (2007) initially quantified the effects of biomass burning at the rural sampling site K-puszta, using the 14 C technique [21]. Current air pollutant investigations are increasingly using simultaneous and coupled analyses of some beneficial chemical compounds [22][23][24][25] and similar techniques have also been applied in Hungary. For example, Salma et al (2017) used a coupled radiocarbon + levoglucosan tracer method to determine that 40% of TC, collected in Budapest in 2014, derived from biomass burning, but the biological sources still accounted for 24% of TC [26].…”