EGU General Assembly 2021
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Meteorological and fire impacts on tropospheric ozone concentration over tropical forest in the Congo Basin

Inês Vieira1, Hans Verbeeck1, Félicien Meunier1, Marc Peaucelle1, Lodewijk Lefevre1,2, Alexander Cheesman3,4, Stephen Sitch5, José Mbifo6, Pascal Boeckx2, and Marijn Bauters1,2
Inês Vieira et al.
  • 1CAVElab, Computational and Applied Vegetation Ecology, Department of Environment, Ghent University, Ghent, Belgium (
  • 2Isotope Bioscience Laboratory - ISOFYS, Department of Green Chemistry and Technology, Ghent University, Ghent, Belgium
  • 3College of Science and Engineering and Centre for Tropical Environmental and Sustainability Science, James Cook University, Cairns, Australia
  • 4College of Engineering, Mathematics, and Physical Sciences, University of Exeter, Exeter, EX4 4QE, UK
  • 5College of Life and Environmental Sciences, University of Exeter, Exeter, EX4 4RJ, UK
  • 6Institut National des Etudes et Recherche Agronomique, Department of Climatology, Yangambi, Democratic Republic of the Congo

Tropospheric ozone is a greenhouse gas, and high tropospheric ozone levels can directly impact plant growth and human health. In the Congo basin, simulations predict high ozone concentrations, induced by high ozone precursor (VOC and NOx) concentrations and high solar irradiation, which trigger the chemical reactions that form ozone. Additionally, biomass burning activities are widespread on the African continent, playing a crucial role in ozone precursor production. How these potentially high ozone levels impact tropical forest primary productivity remains poorly understood, and field-based ozone monitoring is completely lacking from the Congo basin. This study intends to show preliminary results from the first full year of in situ measurements of ozone concentration in the Congo Basin (i.e., Yangambi, Democratic Republic of the Congo). We show the relationships between meteorological variables (temperature, precipitation, radiation, wind direction and speed), fire occurrence (derived from remote sensing products) and ozone concentrations at a new continuous monitoring station in the heart of the Congo Basin. First results show higher daily mean ozone levels (e.g. 43 ppb registered in January 2020) during dry season months (December-February). We identify a strong diurnal cycle, where minimum values of ozone (almost near zero) are registered during night hours, and maximum values (near 100 ppb) are registered during the daytime. We also verify that around 2.5% of the ozone measurements exceeds a toxicity level (potential for ozone to damage vegetation) of 40 ppb. In the longer term, these measurements should improve the accuracy of future model simulations in the Congo Basin and will be used to assess the impact of ozone on the tropical forest’s primary productivity.

How to cite: Vieira, I., Verbeeck, H., Meunier, F., Peaucelle, M., Lefevre, L., Cheesman, A., Sitch, S., Mbifo, J., Boeckx, P., and Bauters, M.: Meteorological and fire impacts on tropospheric ozone concentration over tropical forest in the Congo Basin, EGU General Assembly 2021, online, 19–30 Apr 2021, EGU21-13301,, 2021.

Display materials

Display file

Comments on the display material

to access the discussion