Advancing Air Quality and Carbon Science in Africa

Dates: Wednesday 10 March, Thursday 11 March and Friday 12 March 2021

Online workshop Goal: Foster current collaborations and identify areas for future scientific research.

Workshop summary: Identify strategies to monitor African atmospheric composition to better quantify pollutant and greenhouse gases surface fluxes and atmospheric fate. The overarching goal is to shape pollutant and greenhouse gases abatement strategies to mitigate climate change with improved air quality.

Workshop Outline: Africa is a continent that is projected to double its population by the mid 21^st century. Already many regions have high concentrations of ambient particulate matter and other health relevant pollutants, often driven by desert dust, biogenic, and biomass burning emissions. This is further complicated by the projected future changes in emissions from anthropogenic sources that are expected to increase significantly with the rapid socio-economic development and growth of cities and megacities. Air pollution is thus emerging as a serious problem in Africa that can be mitigated by emission regulation. This effort requires an adequate monitoring of spatial and temporal patterns of pollutants and an improved characterization of sectoral emissions sources and their chemical and physical evolution. The development of an Air Quality forecasting systems dedicated to the continent will serve as a basis to assess health impacts and inform the population. It is also of primary importance to improve our understanding and to accurately quantify the greenhouse gases fluxes across the continents when such large discrepancies remains between top-down and bottom-up estimates.

Because of the lack of African in situ monitoring of air pollutants and the specificity and diversity of biofuel and fossil fuel use from anthropogenic sources, there is a need to assess uncertainties and short-comings of current emissions inventories. Biogenic, biomass burning, and desert dust pollutants are also subject to important errors that in turn impact major cities through long-range transport. This leads to complex vertical structures of gases and aerosols that can lower the reliability of satellite retrievals and are challenging the models. Using field campaign measurements, available networks of observations, satellite retrievals and model simulations, the goal is to accurately assess aerosol and gas abundance and composition in order to better quantify and potentially reduce the impacts on human health, ecosystems, and climate.

• Assess existing observation datasets (monitoring networks and field campaigns), and identify gaps in current scientific understanding.
• Improving estimates of anthropogenic, natural and biomass burning sectoral fluxes.
• Characterize potential errors in satellite retrievals to improve the monitoring of the atmospheric composition and greenhouse gases from space.
• Identifying missing physical and chemical processes and potential emergent constraints in a perturbed tropical environment.
• Development of the next generation of Air Quality forecast models with data assimilation capabilities.

Organizers: Gabriele Pfister, Claire Granier and Benjamin Gaubert