Fig. 4: Year-round variations in BC source contribution in Nairobi.
From: Black carbon emissions from traffic contribute substantially to air pollution in Nairobi, Kenya
a Presents the Δ14C signatures of BC (Δ14CBC) and the corresponding fractional contribution of biomass burning (ƒbiomass), and b shows the Δ14C resolved fossil vs biomass sourced BC concentrations in Nairobi. Δ14C of −1000‰ implies 100% fossil. Roughly every second sample was analyzed for 14C signatures. The prevailing are masses received in Nairobi, and the transition periods are indicated.
