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

Marjan Savadkoohi; Marco Pandolfi; Olivier Favez; Jean Philippe Putaud; Konstantinos Eleftheriadis; Markus Fiebig; Philip K. Hopke; Paolo Laj; Alfred Wiedensohler; Lucas Alados-Arboledas; Susanne Bastian; Benjamin Chazeau; Álvaro Clemente María; Cristina Colombi; Francesca Costabile; David C. Green; Christoph Hueglin; Eleni Liakakou; Krista Luoma; Stefano Listrani; Nikos Mihalopoulos; Nicolas Marchand; Griša Močnik; Jarkko V. Niemi; Jakub Ondráček; Jean Eudes Petit; Oliver V. Rattigan; Cristina Reche; Hilkka Timonen; Gloria Titos; Anja H. Tremper; Stergios Vratolis; Petr Vodička; Eduardo Yubero Funes; Naděžda Zíková; Roy M. Harrison; Tuukka Petäjä; Andrés Alastuey; Xavier Querol

doi:10.1016/j.envint.2024.108553

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

Marjan Savadkoohi^*, Marco Pandolfi^*, Olivier Favez, Jean Philippe Putaud, Konstantinos Eleftheriadis, Markus Fiebig, Philip K. Hopke, Paolo Laj, Alfred Wiedensohler, Lucas Alados-Arboledas, Susanne Bastian, Benjamin Chazeau, Álvaro Clemente María, Cristina Colombi, Francesca Costabile, David C. Green, Christoph Hueglin, Eleni Liakakou, Krista Luoma, Stefano ListraniNikos Mihalopoulos, Nicolas Marchand, Griša Močnik, Jarkko V. Niemi, Jakub Ondráček, Jean Eudes Petit, Oliver V. Rattigan, Cristina Reche, Hilkka Timonen, Gloria Titos, Anja H. Tremper, Stergios Vratolis, Petr Vodička, Eduardo Yubero Funes, Naděžda Zíková, Roy M. Harrison, Tuukka Petäjä, Andrés Alastuey, Xavier Querol

^*Corresponding author for this work

Earth and Environmental Sciences

Research output: Contribution to journal › Article › peer-review

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Abstract

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 (b_abs) to eBC. This study investigates the spatial–temporal variability of the MAC obtained from simultaneous elemental carbon (EC) and b_abs 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.

Original language	English
Article number	108553
Number of pages	17
Journal	Environment international
Volume	185
Early online date	2 Mar 2024
DOIs	https://doi.org/10.1016/j.envint.2024.108553
Publication status	Published - 8 Mar 2024

Bibliographical note

Funding Information:
This work was funded and supported within the framework of the Research Infrastructures Services Reinforcing AQ Monitoring Capacities in European Urban & Industrial AreaS (RI-URBANS) project. The RI-URBANS project (https://riurbans.eu/, contract 101036245), is a European H2020-Green Deal initiative that aims to provide comprehensive tools for the measurement and analysis of advanced AQ parameters (RI-URBANS, 2020). These parameters include eBC, ultrafine particles, and oxidative potential in urban environments, which will consequently allow for the enhanced assessment of AQ policies. RI-URBANS is implementing the ACTRIS (https://www.actris.eu/) strategy for the development of services for improving air quality in Europe. The authors would like to also thank the support from “Agencia Estatal de Investigación” from the Spanish Ministry of Science and Innovation under the project CAIAC (PID2019-108990RB-I00), AIRPHONEMA (PID2022-142160OB-I00), and the Generalitat de Catalunya (AGAUR, SGR-447). M. Savadkoohi would like to thank the Spanish Ministry of Science and Innovation for her FPI grant (PRE-2020-095498). This study is also partly funded by the National Institute for Health Research (NIHR) Health Protection Research Unit in Environmental Exposures and Health, a partnership between UK Health Security Agency (UKHSA) and Imperial College London, and the UK Natural Environment Research Council. The views expressed are those of the author(s) and not necessarily those of the NIHR, UKHSA or the Department of Health and Social Care. The work in Helsinki and Hyytiälä is supported by Academy of Finland flagship “Atmosphere and Climate Competence Center (ACCC), project numbers 337549, 337552, 334792, 328616, 345510 and the Technology Industries of Finland Centennial Foundation Urban Air Quality 2.0 project and European Commission via FOCI-project (grant number 101056783). The work performed in Rome (IT) was supported by ARPA Lazio, the regional Environmental Protection Agency. Measurements at Granada urban station were possible thanks to MCIN/AEI/10.13039/501100011033 and NextGenerationEU/PRTR under the projects PID2020-120015RB-I00 and PID2021-128757OB-I00, ACTRIS-España (CGL2017-90884REDT), and University of Granada Plan Propio through Excellence Research Unit Earth Science and Singular Laboratory AGORA (LS2022-1). Partial support of this work by the project “PANhellenic infrastructure for Atmospheric Composition and climatE change” (MIS 5021516) which is implemented under the Action “Reinforcement of the Research and Innovation Infrastructure”, funded by the Operational Programme “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014-2020) and co-financed by Greece and the European Union (European Regional Development Fund). Partial funding was obtained by Slovenian ARRS/ARIS program P1-0385. Partial support for operating stations in France is received by ACTRIS-FR supported by French Ministery for research and Education and by France2030 initiative under project ANR-21-ESRE-0013. Elche data were possible thanks to the support of European Union NextGenerationEU/PRTR” (CAMBIO project, ref. TED2021-131336B-I00) and by the Valencian Regional Government (Generalitat Valenciana, CIAICO/2021/280 research project). This research was supported by the Ministry of Education, Youth and Sports of the Czech Republic within the Large Research Infrastructure Support Project - ACTRIS Participation of the Czech Republic (ACTRIS-CZ LM2023030).

Funding Information:
This work was funded and supported within the framework of the Research Infrastructures Services Reinforcing AQ Monitoring Capacities in European Urban & Industrial AreaS (RI-URBANS) project. The RI-URBANS project ( https://riurbans.eu/ , contract 101036245), is a European H2020-Green Deal initiative that aims to provide comprehensive tools for the measurement and analysis of advanced AQ parameters ( RI-URBANS, 2020 ). These parameters include eBC, ultrafine particles, and oxidative potential in urban environments, which will consequently allow for the enhanced assessment of AQ policies. RI-URBANS is implementing the ACTRIS ( https://www.actris.eu/ ) strategy for the development of services for improving air quality in Europe.

Publisher Copyright:
© 2024 The Author(s)

Keywords

Absorption
eBC
EC
FAPs
MAC
Rolling MAC
Site specific MAC

ASJC Scopus subject areas

General Environmental Science

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10.1016/j.envint.2024.108553Licence: Creative Commons: Attribution-NonCommercial (CC BY-NC)

108553_ Recommendations for Reporting Equivalent Black CarbonFinal published version, 4.01 MBLicence: Creative Commons: Attribution-NonCommercial (CC BY-NC)

RI-URBANS: Research Infrastructures services reinforcing Air Quality Monitoring Capacities in European Urban & Industrial areaS
Harrison, R.
European Commission
1/10/21 → 30/09/25
Project: EU

Cite this

Savadkoohi, M., Pandolfi, M., Favez, O., Putaud, J. P., Eleftheriadis, K., Fiebig, 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, C., Liakakou, E., Luoma, K., ... Querol, X. (2024). Recommendations for reporting equivalent black carbon (eBC) mass concentrations based on long-term pan-European in-situ observations. Environment international, 185, Article 108553. https://doi.org/10.1016/j.envint.2024.108553

@article{d1131e07ff744dc6adb339ebbc5cb0f1,

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

abstract = "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.",

keywords = "Absorption, eBC, EC, FAPs, MAC, Rolling MAC, Site specific MAC",

author = "Marjan Savadkoohi and Marco Pandolfi and Olivier Favez and Putaud, {Jean Philippe} and Konstantinos Eleftheriadis and Markus Fiebig and Hopke, {Philip K.} and Paolo Laj and Alfred Wiedensohler and Lucas Alados-Arboledas and Susanne Bastian and Benjamin Chazeau and Mar{\'i}a, {{\'A}lvaro Clemente} and Cristina Colombi and Francesca Costabile and Green, {David C.} and Christoph Hueglin and Eleni Liakakou and Krista Luoma and Stefano Listrani and Nikos Mihalopoulos and Nicolas Marchand and Gri{\v s}a Mo{\v c}nik and Niemi, {Jarkko V.} and Jakub Ondr{\'a}{\v c}ek and Petit, {Jean Eudes} and Rattigan, {Oliver V.} and Cristina Reche and Hilkka Timonen and Gloria Titos and Tremper, {Anja H.} and Stergios Vratolis and Petr Vodi{\v c}ka and Funes, {Eduardo Yubero} and Nad{\v e}{\v z}da Z{\'i}kov{\'a} and Harrison, {Roy M.} and Tuukka Pet{\"a}j{\"a} and Andr{\'e}s Alastuey and Xavier Querol",

note = "Funding Information: This work was funded and supported within the framework of the Research Infrastructures Services Reinforcing AQ Monitoring Capacities in European Urban & Industrial AreaS (RI-URBANS) project. The RI-URBANS project (https://riurbans.eu/, contract 101036245), is a European H2020-Green Deal initiative that aims to provide comprehensive tools for the measurement and analysis of advanced AQ parameters (RI-URBANS, 2020). These parameters include eBC, ultrafine particles, and oxidative potential in urban environments, which will consequently allow for the enhanced assessment of AQ policies. RI-URBANS is implementing the ACTRIS (https://www.actris.eu/) strategy for the development of services for improving air quality in Europe. The authors would like to also thank the support from “Agencia Estatal de Investigaci{\'o}n” from the Spanish Ministry of Science and Innovation under the project CAIAC (PID2019-108990RB-I00), AIRPHONEMA (PID2022-142160OB-I00), and the Generalitat de Catalunya (AGAUR, SGR-447). M. Savadkoohi would like to thank the Spanish Ministry of Science and Innovation for her FPI grant (PRE-2020-095498). This study is also partly funded by the National Institute for Health Research (NIHR) Health Protection Research Unit in Environmental Exposures and Health, a partnership between UK Health Security Agency (UKHSA) and Imperial College London, and the UK Natural Environment Research Council. The views expressed are those of the author(s) and not necessarily those of the NIHR, UKHSA or the Department of Health and Social Care. The work in Helsinki and Hyyti{\"a}l{\"a} is supported by Academy of Finland flagship “Atmosphere and Climate Competence Center (ACCC), project numbers 337549, 337552, 334792, 328616, 345510 and the Technology Industries of Finland Centennial Foundation Urban Air Quality 2.0 project and European Commission via FOCI-project (grant number 101056783). The work performed in Rome (IT) was supported by ARPA Lazio, the regional Environmental Protection Agency. Measurements at Granada urban station were possible thanks to MCIN/AEI/10.13039/501100011033 and NextGenerationEU/PRTR under the projects PID2020-120015RB-I00 and PID2021-128757OB-I00, ACTRIS-Espa{\~n}a (CGL2017-90884REDT), and University of Granada Plan Propio through Excellence Research Unit Earth Science and Singular Laboratory AGORA (LS2022-1). Partial support of this work by the project “PANhellenic infrastructure for Atmospheric Composition and climatE change” (MIS 5021516) which is implemented under the Action “Reinforcement of the Research and Innovation Infrastructure”, funded by the Operational Programme “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014-2020) and co-financed by Greece and the European Union (European Regional Development Fund). Partial funding was obtained by Slovenian ARRS/ARIS program P1-0385. Partial support for operating stations in France is received by ACTRIS-FR supported by French Ministery for research and Education and by France2030 initiative under project ANR-21-ESRE-0013. Elche data were possible thanks to the support of European Union NextGenerationEU/PRTR” (CAMBIO project, ref. TED2021-131336B-I00) and by the Valencian Regional Government (Generalitat Valenciana, CIAICO/2021/280 research project). This research was supported by the Ministry of Education, Youth and Sports of the Czech Republic within the Large Research Infrastructure Support Project - ACTRIS Participation of the Czech Republic (ACTRIS-CZ LM2023030). Funding Information: This work was funded and supported within the framework of the Research Infrastructures Services Reinforcing AQ Monitoring Capacities in European Urban & Industrial AreaS (RI-URBANS) project. The RI-URBANS project ( https://riurbans.eu/ , contract 101036245), is a European H2020-Green Deal initiative that aims to provide comprehensive tools for the measurement and analysis of advanced AQ parameters ( RI-URBANS, 2020 ). These parameters include eBC, ultrafine particles, and oxidative potential in urban environments, which will consequently allow for the enhanced assessment of AQ policies. RI-URBANS is implementing the ACTRIS ( https://www.actris.eu/ ) strategy for the development of services for improving air quality in Europe. Publisher Copyright: {\textcopyright} 2024 The Author(s)",

year = "2024",

month = mar,

day = "8",

doi = "10.1016/j.envint.2024.108553",

language = "English",

volume = "185",

journal = "Environment international",

issn = "0160-4120",

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Savadkoohi, M, Pandolfi, M, Favez, O, Putaud, JP, Eleftheriadis, K, Fiebig, M, Hopke, PK, Laj, P, Wiedensohler, A, Alados-Arboledas, L, Bastian, S, Chazeau, B, María, ÁC, Colombi, C, Costabile, F, Green, DC, Hueglin, C, Liakakou, E, Luoma, K, Listrani, S, Mihalopoulos, N, Marchand, N, Močnik, G, Niemi, JV, Ondráček, J, Petit, JE, Rattigan, OV, Reche, C, Timonen, H, Titos, G, Tremper, AH, Vratolis, S, Vodička, P, Funes, EY, Zíková, N, Harrison, RM, Petäjä, T, Alastuey, A & Querol, X 2024, 'Recommendations for reporting equivalent black carbon (eBC) mass concentrations based on long-term pan-European in-situ observations', Environment international, vol. 185, 108553. https://doi.org/10.1016/j.envint.2024.108553

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 - Funding Information: This work was funded and supported within the framework of the Research Infrastructures Services Reinforcing AQ Monitoring Capacities in European Urban & Industrial AreaS (RI-URBANS) project. The RI-URBANS project (https://riurbans.eu/, contract 101036245), is a European H2020-Green Deal initiative that aims to provide comprehensive tools for the measurement and analysis of advanced AQ parameters (RI-URBANS, 2020). These parameters include eBC, ultrafine particles, and oxidative potential in urban environments, which will consequently allow for the enhanced assessment of AQ policies. RI-URBANS is implementing the ACTRIS (https://www.actris.eu/) strategy for the development of services for improving air quality in Europe. The authors would like to also thank the support from “Agencia Estatal de Investigación” from the Spanish Ministry of Science and Innovation under the project CAIAC (PID2019-108990RB-I00), AIRPHONEMA (PID2022-142160OB-I00), and the Generalitat de Catalunya (AGAUR, SGR-447). M. Savadkoohi would like to thank the Spanish Ministry of Science and Innovation for her FPI grant (PRE-2020-095498). This study is also partly funded by the National Institute for Health Research (NIHR) Health Protection Research Unit in Environmental Exposures and Health, a partnership between UK Health Security Agency (UKHSA) and Imperial College London, and the UK Natural Environment Research Council. The views expressed are those of the author(s) and not necessarily those of the NIHR, UKHSA or the Department of Health and Social Care. The work in Helsinki and Hyytiälä is supported by Academy of Finland flagship “Atmosphere and Climate Competence Center (ACCC), project numbers 337549, 337552, 334792, 328616, 345510 and the Technology Industries of Finland Centennial Foundation Urban Air Quality 2.0 project and European Commission via FOCI-project (grant number 101056783). The work performed in Rome (IT) was supported by ARPA Lazio, the regional Environmental Protection Agency. Measurements at Granada urban station were possible thanks to MCIN/AEI/10.13039/501100011033 and NextGenerationEU/PRTR under the projects PID2020-120015RB-I00 and PID2021-128757OB-I00, ACTRIS-España (CGL2017-90884REDT), and University of Granada Plan Propio through Excellence Research Unit Earth Science and Singular Laboratory AGORA (LS2022-1). Partial support of this work by the project “PANhellenic infrastructure for Atmospheric Composition and climatE change” (MIS 5021516) which is implemented under the Action “Reinforcement of the Research and Innovation Infrastructure”, funded by the Operational Programme “Competitiveness, Entrepreneurship and Innovation” (NSRF 2014-2020) and co-financed by Greece and the European Union (European Regional Development Fund). Partial funding was obtained by Slovenian ARRS/ARIS program P1-0385. Partial support for operating stations in France is received by ACTRIS-FR supported by French Ministery for research and Education and by France2030 initiative under project ANR-21-ESRE-0013. Elche data were possible thanks to the support of European Union NextGenerationEU/PRTR” (CAMBIO project, ref. TED2021-131336B-I00) and by the Valencian Regional Government (Generalitat Valenciana, CIAICO/2021/280 research project). This research was supported by the Ministry of Education, Youth and Sports of the Czech Republic within the Large Research Infrastructure Support Project - ACTRIS Participation of the Czech Republic (ACTRIS-CZ LM2023030). Funding Information: This work was funded and supported within the framework of the Research Infrastructures Services Reinforcing AQ Monitoring Capacities in European Urban & Industrial AreaS (RI-URBANS) project. The RI-URBANS project ( https://riurbans.eu/ , contract 101036245), is a European H2020-Green Deal initiative that aims to provide comprehensive tools for the measurement and analysis of advanced AQ parameters ( RI-URBANS, 2020 ). These parameters include eBC, ultrafine particles, and oxidative potential in urban environments, which will consequently allow for the enhanced assessment of AQ policies. RI-URBANS is implementing the ACTRIS ( https://www.actris.eu/ ) strategy for the development of services for improving air quality in Europe. Publisher Copyright: © 2024 The Author(s)

PY - 2024/3/8

Y1 - 2024/3/8

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 - eBC

KW - EC

KW - FAPs

KW - MAC

KW - Rolling MAC

KW - Site specific MAC

UR - http://www.scopus.com/inward/record.url?scp=85187240472&partnerID=8YFLogxK

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 -

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

Abstract

Bibliographical note

Keywords

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RI-URBANS: Research Infrastructures services reinforcing Air Quality Monitoring Capacities in European Urban & Industrial areaS

Cite this