Interannual Variability in the Source Location of North African Dust Transported to the Amazon

• Published in: Geophysical Research Letters
• Main Authors: Barkley, Anne E., Pourmand, Ali, Longman, Jack, Sharifi, Arash, Prospero, Joseph M., Panechou, Kathy, Bakker, Natalie, Drake, Nick, Guinoiseau, Damien, Gaston, Cassandra J.
• Other Authors: Géosciences Paris Saclay (GEOPS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: North African dust; provenance; nutrients; Amazon; North Atlantic Ocean; [SDU]Sciences of the Universe [physics]; [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; North Atlantic
• Online Access: https://hal-insu.archives-ouvertes.fr/insu-03745284; https://hal-insu.archives-ouvertes.fr/insu-03745284/document; https://hal-insu.archives-ouvertes.fr/insu-03745284/file/Geophysical%20Research%20Letters%20-%202022%20-%20Barkley%20-%20Interannual%20Variability%20in%20the%20Source%20Location%20of%20North%20African%20Dust.pdf; https://doi.org/10.1029/2021GL097344

International audience African dust is transported to South America (SA) every winter and spring. Hypotheses suggest that either Western or Central North Africa (e.g., Bodélé Depression) is the main source of transported dust, yet these notions remain largely untested with geochemical data. Using 2 years of isotopic measurements (strontium and neodymium) of African dust collected in SA integrated into a statistical model, we identified strong interannual variability in dust source region. Central North Africa supplied 44% of long-range transported dust in winter 2016 while the Western region accounted for 53% of dust in winter 2014. We propose the variability is due to differences in the strength of the Libyan High and precipitation over the Gulf of Guinea and Atlantic Ocean between the 2 years. Our findings can improve constraints of dust nutrient deposition and predictions of how changes in climate impact the source and magnitude of dust transported to the Amazon.