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Mineral dust can significantly impact climate and biogeochemical cycles on Earth. To understand dust provenance, an accurate characterization of dust sources and emission regions is required. In this study, we combine rare-earth element patterns, elemental ratios, and radiogenic Sr-Nd-Pb isotopes to discriminate dust sources from key regions in North Africa responsible for similar to 55% of the total dust load emitted annually on Earth. This new dataset, based on fifty-nine analyses of deflatable fine soil material, improves our current knowledge about North African dust sources, especially those underrepresented in Saharan-Sahelian regions. Six potential source areas (PSA) - Libya-Algeria-Mali (PSA(LAM)), Libya-Egypt (PSA(LE)), Bodele Depression (PSA(BD)), Mali Center (PSA(MC)), West African Coast (PSA(WAC)) and Mauritania (PSA(Ma)) - are defined based on several lithogenic tracers as well as on the geological subdivision of North African geological provinces, providing a unique chemical and isotope fingerprint for each PSA. For example, the PSA(BD) - the main dust activation area in North Africa - is clearly distinguished from western African sources using Pb isotopes. Major elements show a large variability within each PSA and are not alone diagnostically useful. Comparison of the newly defined PSA with aerosols collected in remote locations over the North Atlantic shows that their sources are predominantly from western African regions (PSA(LAM) and PSA(WAC)). Bodele-derived dust has a limited impact on the bulk dust transported over the tropical North Atlantic, regardless of the season and altitude of dust transport. The low impact of the Bodele Depression can be explained by a high deposition rate (wet and dry) of aerosols along its southwestward trajectory. A detailed analysis of dust collected over South America during winter will be essential to confirm this observation at a global scale. The present dataset can be efficiently used to track modern dust emiss

During the last African Humid Period (AHP; 15-5 ka), many lakes in the East African Rift System (EARS) experienced pronounced lake-level variations that dramatically transformed the hydrological landscape. Currently dry, saline or marshy-wetland terminal lakes became vast waterbodies, interconnected via overflow sills resulting in the formation of a several thousand-kilometre-long chain of lakes in the EARS. A quantitative, process-based understanding of these hydrological systems can advance our interpretation of past hydroclimate variability from proxy records. Here, we provide a critical modern hydrological dataset for the data-sparse Lake Chew Bahir basin in southern Ethiopia. Driven by modern data, an isotope-enabled hydro-balance model was developed to assess how increases in rainfall modulate delta O-18 and Sr-87/Sr-86 variability. Considering a terminal Lake Chew Bahir scenario, humid conditions resulted in higher lake delta O-18 (similar to+14 parts per thousand) due to increased evaporation and longer water residence times. At the same time Sr-87/Sr-86 Sr decreased from 0.7064 to 0.7061 due to an increased riverine Sr flux characterised by lower, unradiogenic Sr-87/Sr-86 ratios. In a modelling scenario where Lake Chew Bahir became a flow-through system with interconnectivity between lakes Abaya, Chamo, Chew Bahir and Turkana, higher lake delta O-18 (similar to+12 parts per thousand) relative to present was found, but 8 18 0 was lower than in the terminal lake scenario. The lake water Sr-87/Sr-86 ratios (<0.7061) were also slightly lower. A moderate concomitant change in rainfall input delta O-18 of similar to 1 parts per thousand in step with hydrological reorganisation resulted in the lowest lake delta O-18 (similar to+5 parts per thousand). Modelled delta O-18 values were similar to the delta O-18 range of endogenic carbonates from sedimentary cores from Lake Chew Bahir at the onset of the AHP, supporting the validity of our model, and suggesting that ev