Recommendations for reporting equivalent black carbon (eBC) mass concentrations based on long-term pan-European in-situ observations

0583845 - ÚCHP 2025 RIV GB eng J - Journal Article
Savadkoohi, M. - Pandolfi, M. - Favez, O. - Putaud, J.-P. - Eleftheriadis, K. - Feibig, M. - Hopke, P.K. - Laj, P. - Wiedensohler, A. - Alados-Arboledas, L. - Bastian, S. - Chazeau, B. - María, Á.C. - Colombi, C. - Costabile, F. - Green, D.C. - Hueglin, Ch. - Liakakou, E. - Luoma, K. - Listrani, S. - Mihalopoulos, N. - Marchand, N. - Močnik, G. - Niemi, J.V. - Ondráček, Jakub - Petit, J.-E. - Rattigan, O.V. - Reche, C. - Timonen, H. - Titos, G. - Tremper, A.H. - Vratolis, S. - Vodička, Petr - Funes, E.Y. - Zíková, Naděžda - Harrison, R.M. - Patäjä, T. - Alastuey, A. - Querol, X.
Recommendations for reporting equivalent black carbon (eBC) mass concentrations based on long-term pan-European in-situ observations.
Environment International. Roč. 185, MAR 2024 (2024), č. článku 108553. ISSN 0160-4120. E-ISSN 1873-6750
R&D Projects: GA MŠMT(CZ) LM2023030
Institutional support: RVO:67985858
Keywords : absorption * site specific MAC * rolling MAC * FAPs
OECD category: Meteorology and atmospheric sciences
Impact factor: 11.8, year: 2022
Method of publishing: Open access
https://www.sciencedirect.com/science/article/pii/S0160412024001399?via%3Dihub

A reliable determination of equivalent black carbon (eBC) mass concentrations derived from filter absorption photometers (FAPs) measurements depends on the appropriate quantification of the mass absorption crosssection (MAC) for converting the absorption coefficient (babs) to eBC. This study investigates the spa tial–temporal variability of the MAC obtained from simultaneous elemental carbon (EC) and babs measurements performed at 22 sites. We compared different methodologies for retrieving eBC integrating different options for calculating MAC including: locally derived, median value calculated from 22 sites, and site-specific rolling MAC. The eBC concentrations that underwent correction using these methods were identified as LeBC (local MAC), MeBC (median MAC), and ReBC (Rolling MAC) respectively. Pronounced differences (up to more than 50 %) were observed between eBC as directly provided by FAPs (NeBC, Nominal instrumental MAC) and ReBC due to the differences observed between the experimental and nominal MAC values. The median MAC was 7.8 ± 3.4 m2 g-1 from 12 aethalometers at 880 nm, and 10.6 ± 4.7 m2 g-1 from 10 MAAPs at 637 nm. The experimental MAC showed significant site and seasonal dependencies, with heterogeneous patterns between summer and winter in different regions. In addition, long-term trend analysis revealed statistically significant (s.s.) decreasing trends in EC. Interestingly, we showed that the corresponding corrected eBC trends are not independent of the way eBC is calculated due to the variability of MAC. NeBC and EC decreasing trends were consistent at sites with no significant trend in experimental MAC. Conversely, where MAC showed s.s. trend, the NeBC and EC trends were not consistent while ReBC concentration followed the same pattern as EC. These results underscore the importance of accounting for MAC variations when deriving eBC measurements from FAPs and emphasize the necessity of incorporating EC observations to constrain the uncertainty associated with eBC.
Permanent Link: https://hdl.handle.net/11104/0351846