Long term variability of carbonaceous aerosols in a West African savanna over a 15 year-period (Lamto, Côte d’Ivoire)
Abstract
In the framework of the International Network to study Deposition and Atmospheric chemistry in AFrica (INDAAF) program, we report a 15-year dataset (2006-2020) of total carbon (TC), organic carbon (OC) and elemental carbon (EC) aerosols in PM2.5 and PM10 at the Lamto site (Cote d’Ivoire), a representative West African natural wet savanna. Harmonized protocols ensure global comparability, making this dataset the longest continuous African record and allowing us to document carbonaceous aerosol variability from weekly up to annual scales. Annual EC concentrations in PM2.5 and PM10 ranged from 1 to 1.35 μg m−3 and OC from 3 to 5.6 μg m−3 respectively, with dry-season (November-March) values about twice those of the wet season (April-October). Strong seasonal peaks were linked to biomass burning and Harmattan transport, while higher wet-season OC/EC ratios reflected incomplete combustion and secondary organic carbon formation. Back trajectories and OC/EC emission inventories indicate a decline in large-scale savanna fires but rising agricultural waste burning and growing local anthropogenic contributions. Upward OC and EC trends (+3–5 % yr−1) highlight shifting emission sources and the growing anthropogenic impact on aerosol burdens over West African savannas. This integrated approach combining in-situ monitoring, emission inventories, and trajectory analysis—offers valuable insight into regional aerosol dynamics and supports the evaluation of satellite products, air quality strategies, and chemistry-transport models.
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BibTeX
@article{ochou2026long,
title = {{Long term variability of carbonaceous aerosols in a West African savanna over a 15 year-period (Lamto, Côte d’Ivoire)}},
author = {Arsène Ochou and Corinne Galy-Lacaux and Véronique Yoboué and Catherine Liousse and Béatrice Marticorena and Véronique Pont and Jean-Eudes Petit and Marie Roumy Ouafo-Leumbe and Estelle Amanda Ndengué and Sekou Keita and Money Ossohou and Maria Dias Alves},
journal = {Atmospheric Environment},
year = {2026},
month = may,
doi = {10.1016/j.atmosenv.2026.121874},
url = {https://hal.science/hal-05827457v1},
note = {CC BY-NC-ND 4.0},
}
RIS
TY - JOUR
TI - Long term variability of carbonaceous aerosols in a West African savanna over a 15 year-period (Lamto, Côte d’Ivoire)
AU - Arsène Ochou
AU - Corinne Galy-Lacaux
AU - Véronique Yoboué
AU - Catherine Liousse
AU - Béatrice Marticorena
AU - Véronique Pont
AU - Jean-Eudes Petit
AU - Marie Roumy Ouafo-Leumbe
AU - Estelle Amanda Ndengué
AU - Sekou Keita
AU - Money Ossohou
AU - Maria Dias Alves
PY - 2026
DA - 2026/05/15
JO - Atmospheric Environment
DO - 10.1016/j.atmosenv.2026.121874
UR - https://hal.science/hal-05827457v1
AB - In the framework of the International Network to study Deposition and Atmospheric chemistry in AFrica (INDAAF) program, we report a 15-year dataset (2006-2020) of total carbon (TC), organic carbon (OC) and elemental carbon (EC) aerosols in PM2.5 and PM10 at the Lamto site (Cote d’Ivoire), a representative West African natural wet savanna. Harmonized protocols ensure global comparability, making this dataset the longest continuous African record and allowing us to document carbonaceous aerosol variability from weekly up to annual scales. Annual EC concentrations in PM2.5 and PM10 ranged from 1 to 1.35 μg m−3 and OC from 3 to 5.6 μg m−3 respectively, with dry-season (November-March) values about twice those of the wet season (April-October). Strong seasonal peaks were linked to biomass burning and Harmattan transport, while higher wet-season OC/EC ratios reflected incomplete combustion and secondary organic carbon formation. Back trajectories and OC/EC emission inventories indicate a decline in large-scale savanna fires but rising agricultural waste burning and growing local anthropogenic contributions. Upward OC and EC trends (+3–5 % yr−1) highlight shifting emission sources and the growing anthropogenic impact on aerosol burdens over West African savannas. This integrated approach combining in-situ monitoring, emission inventories, and trajectory analysis—offers valuable insight into regional aerosol dynamics and supports the evaluation of satellite products, air quality strategies, and chemistry-transport models.
SN - 1352-2310
SN - 1873-2844
ER -