Brown carbon emissions from laboratory combustion of Eurasian arctic-boreal and South African savanna biomass
Year: 2025
Type: article
Abstract: . Warming climate is predicted to increase forest fires which can be a major source of black and brown carbon (BC and BrC) into the atmosphere. Unlike North American forest fires, very limited studies have characterized North Eurasian biomass burning (BB) emissions. In this work, we defined the emission factors of carbonaceous aerosols and characterized light absorption of BrC emitted from boreal and peat burning through offline filter extraction method. The results were compared to African savanna emissions. Effects of atmospheric dilution and oxidative aging on BrC absorptivity were investigated for selected BB emissions sampled into an environmental chamber. Organic carbon (OC) and elemental carbon (EC) emission factors of fresh BB emissions ranged between 1.30–89.9 g kg-1 and 0.01–4.80 g kg-1 respectively. Methanol soluble OC (MSOC) represented more than 92 % of fresh BB emissions but intrinsic chemical differences among samples resulted in MACMSOC values ranging from 0.46–1.48 m2 g-1 at 365 nm. Fresh BB emissions formed weakly absorbing BrC with k550_MSOC ranging from 0.002 and 0.011. Water soluble OC (WSOC) fractions varied among fresh BB emissions but overall exhibited higher MAC365 than MSOC. Dilution-related evaporative loss in environmental chamber resulted in less volatile OC, making them less soluble in methanol. Photochemical and dark oxidative aging further increased the ELVOC fraction of the organics along with oxidation state. Our estimated OC-EC emission factors and kMSOC for fresh BB emissions can be used for future modelling purposes. Further online measurements are needed to account for non-soluble strong BrC in aged BB emissions.
Authors: Arya Mukherjee, Anni Hartikainen, Markus Somero, Viljami Luostari, Mika Ihalainen, Christopher P. Rüger, Timo Kekäläinen, Ville H. Nissinen, Luis M. F. Barreira, Hanna Koponen, Tuukka Kokkola, Delun Li, Lejish Vettikkat, Pasi Yli-Pirilä, Muhammad Shahzaib, Meri M. Ruppel, Ville Vakkari, Kerneels Jaars, Stefan J. Siebert, Angela Buchholz, Kajar Köster, Pieter G. van Zyl, Hilkka Timonen, Niko Kinnunen, Janne Jänis, Annele Virtanen, Aki Virkkula, Olli Sippula
Language: English
Subfield: Atmospheric Science
Field: Earth and Planetary Sciences
Domain: Physical Sciences
SDG: Climate action
Open Access status: gold
Estimated APC paid: $1,725
Awards: G2204757554, Solutions for Sustainable Access to Atmospheric Research Facilities, G31730716, G3729462117, Redefining open biomass burning aerosol emissions, G434337789, G4937468798, Atmosphere and Climate Competence Center (ACCC), Black and Brown Carbon in the Atmosphere and the Cryosphere, G7723866977, Fire in the Arctic – Trends and sources of Arctic Black and Brown Carbon for targeted climate change mitigation, Black and Brown Carbon in the Atmosphere and the Cryosphere, Atmosphere and Climate Competence Center (ACCC)
OpenAlex ID: W4416627257