Atmospheric composition of West Africa: highlights from the AMMA international program

Abstract

The atmospheric composition of West Africa reflects the interaction of various dynamical and chemical systems (i.e. biogenic, urban, convective and long-range transport) with signatures from local to continental scales. Recent measurements performed during the African Monsoon Multidisciplinary Analyses (AMMA) observational periods in 2005 and 2006 provide new data which has allowed new insight into the processes within these systems that control the distribution of ozone and its precursors. Using these new data and recently published results, we provide an overview of these systems with a particular emphasis on ozone distributions over West Africa during the wet season.

Global-scale atmosphere monitoring by in-service aircraft – current achievements and future prospects of the European Research Infrastructure IAGOS

“…Sauvage et al (2007) further explained the interhemispheric transport pathway, which results in the observed ozone and CO profiles on both sides of the equator. These detailed analyses of West African data supported the preparation and analysis of the atmospheric composition data recorded in the framework of the international African Monsoon Multidisciplinary Analyses (AMMA) programme (Mari et al, 2011) that took place in 2005Á 2006. MOZAIC helped provide the long-term and regional perspective to place the AMMA data into a wider spatial and temporal context (Thouret et al, 2009).…”

HO<sub>x</sub> observations over West Africa during AMMA: impact of isoprene and NO<sub>x</sub>

“…The African Monsoon Multidisciplinary Analyses (AMMA) field campaign was a large international programme to look at a range of environmental issues in the West African region between (Redelsperger et al, 2006Lebel et al, 2010;Reeves et al, 2010;Mari et al, 2010). During the period between 17 July to 17 August 2006 the UK FAAM BAe146 research aircraft was stationed in Niamey, Niger, and undertook 21 flights from that base.…”

A meteorological and chemical overview of the DACCIWA field campaign in West Africa in June–July 2016

“…The atmospheric composition over southern West Africa (SWA hereafter) during the wet season is a complex combination of air masses transported from remote sources, bringing desert dust or biomass burning aerosol, and local anthropogenic pollution (Mari et al, 2011). The Sahara desert to the north of the region is the largest aerosol source in the world and the transport of dust southwards is a significant source of aerosol for SWA (e.g.…”

“…The dense vegetation can emit large quantities of biogenic compounds (isoprene, monoterpenes, etc. ), which profoundly alter the gas and aerosol composition in the region (Mari et al, 2011). The relative role of local biogenic and anthropogenic emissions, the long-range transport of other compounds into the SWA atmosphere, coupled to the peculiar dynamics of the region during the monsoonal period leads to a chemically complex region.…”