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

Imre Salma,Virág Gergely,István Major,Attila Machon,Tamás Varga,Anikó Vasanits-Zsigrai,Mihály Molnár

doi:10.5194/acp-20-4295-2020

Imre Salma, Virág Gergely + Show 5 more

Open Access

https://doi.org/10.5194/acp-20-4295-2020

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Abstract

Abstract. 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 PM2.5 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 PM2.5 mass, with a modest seasonal variation and with a slightly increasing tendency from the regional background to the city centre (from 32 % to 39 %). A 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 (ECFF and OCFF, respectively), EC and OC from biomass burning (BB) (ECBB and OCBB, respectively), and OC from biogenic sources (OCBIO). Fossil fuel combustion showed rather constant daily or monthly 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 %) 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 % 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 %–50 % each. In July, biogenic sources became the major source type 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 July. The ECFF made up more than 90 % of EC in April and July, while in October and January, the contributions of ECBB 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.

Highlights

Introduction and objectivesCarbonaceous aerosol constituents make up a major part (e.g. 20 %–60 % in the continental mid-latitudes and up to 90 % in tropical forests) of the PM2.5 mass (Kanakidou et al, 2005; Fuzzi et al, 2015)
The median concentrations of SO2, NO, NO2 and PM10 mass over the sampling time intervals were larger in the city centre than in the suburban area in all months (Table S2)
The major carbonaceous aerosol species of organic carbon (OC) and elemental carbon (EC) were apportioned among fossil fuel (FF) combustion, biomass burning (BB) and biogenic sources in various types of atmospheric environments of interest in the Carpathian Basin in different months representing the different seasons

Summary

Introduction

Introduction and objectivesCarbonaceous aerosol constituents make up a major part (e.g. 20 %–60 % in the continental mid-latitudes and up to 90 % in tropical forests) of the PM2.5 mass (Kanakidou et al, 2005; Fuzzi et al, 2015). Their largest emission or production source types are fossil fuel (FF) combustion, biomass burning (BB) and biogenic sources (Le Quéré et al, 2018) These processes represent the highest source of certain important aerosol species such as soot (species mainly containing C with imperfect or fragmented graphitic structure; Andreae and Gelencsér, 2006) and of some pollutant or greenhouse gases such as CO, NOx, CO2 and volatile organic compounds (VOCs) on a global spatial scale (Wiedinmyer et al, 2011; Von Schneidemesser et al, 2015; Tian et al, 2016). Highly relevant to estimate the relative contribution of FF combustion, BB and biogenic sources to major carbonaceous aerosol species, namely to organic carbon (OC) and elemental carbon (EC)

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