TY - JOUR
T1 - Recommendations for reporting equivalent black carbon (eBC) mass concentrations based on long-term pan-European in-situ observations
AU - Savadkoohi, Marjan
AU - Pandolfi, Marco
AU - Favez, Olivier
AU - Putaud, Jean Philippe
AU - Eleftheriadis, Konstantinos
AU - Fiebig, Markus
AU - Hopke, Philip K.
AU - Laj, Paolo
AU - Wiedensohler, Alfred
AU - Alados-Arboledas, Lucas
AU - Bastian, Susanne
AU - Chazeau, Benjamin
AU - María, Álvaro Clemente
AU - Colombi, Cristina
AU - Costabile, Francesca
AU - Green, David C.
AU - Hueglin, Christoph
AU - Liakakou, Eleni
AU - Luoma, Krista
AU - Listrani, Stefano
AU - Mihalopoulos, Nikos
AU - Marchand, Nicolas
AU - Močnik, Griša
AU - Niemi, Jarkko V.
AU - Ondráček, Jakub
AU - Petit, Jean Eudes
AU - Rattigan, Oliver V.
AU - Reche, Cristina
AU - Timonen, Hilkka
AU - Titos, Gloria
AU - Tremper, Anja H.
AU - Vratolis, Stergios
AU - Vodička, Petr
AU - Funes, Eduardo Yubero
AU - Zíková, Naděžda
AU - Harrison, Roy M.
AU - Petäjä, Tuukka
AU - Alastuey, Andrés
AU - Querol, Xavier
N1 - Publisher Copyright:
© 2024 The Author(s)
PY - 2024/3
Y1 - 2024/3
N2 - 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 cross-section (MAC) for converting the absorption coefficient (babs) to eBC. This study investigates the spatial–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.
AB - 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 cross-section (MAC) for converting the absorption coefficient (babs) to eBC. This study investigates the spatial–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.
KW - Absorption
KW - EC
KW - FAPs
KW - MAC
KW - Rolling MAC
KW - Site specific MAC
KW - eBC
UR - https://www.scopus.com/pages/publications/85187240472
U2 - 10.1016/j.envint.2024.108553
DO - 10.1016/j.envint.2024.108553
M3 - Article
C2 - 38460240
AN - SCOPUS:85187240472
SN - 0160-4120
VL - 185
JO - Environment international
JF - Environment international
M1 - 108553
ER -