The Aerosols, Radiation and Clouds in southern Africa (AEROCLO-sA) field campaign in Namibia: overview of objectives, first research highlights and way forward

The AEROCLO-sA project (Aerosol, Radiation and CLOuds in southern Africa) investigates the role of aerosols on the regional climate of southern Africa. This is a unique environment where natural and anthropogenic aerosols encounter a semi-permanent and extended stratocumulus cloud deck. The project aims to improve our understanding of aerosol-cloud-radiation interactions over coastal southern Africa in various landscapes and under various meteorological conditions to investigate the dynamical, chemical and radiative processes involved in their life cycle. AEROCLO-sA is based on a field campaign conducted in August/September 2017 over Namibia. An aircraft equipped with active and passive remote sensors as well as aerosol in situ probes performed a total of 30 research flight hours over northern Namibia. The focus laid on terrigenous aerosol emission over land as well as biomass burning aerosol plumes which were advected from Angola, and their subsequent transport over the marine clouds over the Atlantic Ocean. Concomitantly, an instrumented mobile station was implemented at the Namibian coast in order to measure boundary layer aerosols at the ocean-atmosphere interface using a state-of-the-art suite of in situ aerosol probes as well as balloon-borne dynamics and thermodynamics observations of the lower troposphere. This presentation presents an overview of the AEROCLO-sA field campaign as well as first highlights from the airborne and surface-based observations. We expect these observations to significantly contribute to improving the representation of aerosol-cloud-radiation interactions over the region in climate models. They also will be instrumental in promoting capacity building in Namibia and will support policies towards a more sustainable development for the region.