Development of an air quality early warning system for eastern and southern Africa

Air pollution in Eastern and Southern Africa (E&SA) is a severe public health issue, causing over 23,000 premature deaths annually and widespread respiratory problems. To mitigate this problem, we are developing a regional air quality forecasting system system that provides a 48 hour air quality forecast over E&SA under a NASA funded SERVIR project. To help the stakeholders understand past trends in air quality,  we have also developed a regional air quality atlas based on the Copernicus Atmosphere Monitoring System. This project is being carried out in collaboration with local stakeholders. This system is being intentionally designed to address specific regional needs, priorities, and environmental challenges, and can aid informed decision-making and regional planning in response to local mandates. Our regional air quality forecasting system is based on the Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) employed at 15 km grid spacing. Aerosol optical depth (AOD) retrievals from the Visible Infrared Imaging Radiometer Suite (VIIRS) satellite are assimilated daily using the community Gridpoint Statistical Interpolation (GSI) framework to improve aerosol initialization. Meteorological data from the Global Forecast System (GFS), anthropogenic emissions based on CAMS annual estimates, and real-time fire emissions from the Fire Inventory from NCAR (FINN) are used in the forecast. Initial simulations, focusing on June 2022, capture major regional pollution events, including wildfires, dust storms, and local anthropogenic emissions. Challenges such as validation in data-sparse regions and high cloud coverage in tropical areas, which complicates data assimilation, will be addressed. This system has been installed for operational air quality forecasting at Meteo Rwanda and has been running operationally since Oct 2024. This talk will describe the development of this system in detail.