Revisiting atmospheric dust export to the Southern Hemisphere ocean: Biogeochemical implications

• Published in: Global Biogeochemical Cycles
• Main Authors: Wagener, Thibaut, Guieu, Cécile, Losno, Rémi, Bonnet, Sophie, Mahowald, Natalie
• Other Authors: Laboratoire d'océanographie de Villefranche (LOV), Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Laboratoire Interuniversitaire des Systèmes Atmosphériques (LISA (UMR_7583)), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Laboratoire d'Océanographie Physique et Biogéochimique (LOPB), Université de la Méditerranée - Aix-Marseille 2-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), National Center for Atmospheric Research Boulder (NCAR)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2008
• Subjects: [SDU.OCEAN]Sciences of the Universe [physics]/Ocean; Atmosphere; Pacific; Southern Ocean
• Online Access: https://hal.archives-ouvertes.fr/hal-02567410; https://hal.archives-ouvertes.fr/hal-02567410/document; https://hal.archives-ouvertes.fr/hal-02567410/file/2007GB002984.pdf; https://doi.org/10.1029/2007GB002984

International audience Aerosol concentrations in the Southern Hemisphere are largely undersampled. This study presents a chemical and physical description of dust particles collected on board research vessels in the southeast Pacific (SEPS) and the Southern Ocean (SOKS). Concentrations of dust were 6.1 ± 2.4 ng m À3 for SEPS and 13.0 ± 6.3 ng m À3 for SOKS. Dust fluxes, derived from those concentrations, were 9.9 ± 3.7 mg m À2 d À1 for SEPS and 38 ± 14 mg m À2 d À1 for SOKS and are shown to be representative of actual fluxes in those areas. Dust and iron deposition are up to 2 orders of magnitude lower than former predictions. A map of dust deposition on the Southern Hemisphere is proposed by incorporating those in situ measurements into a dust model. This study confirms that dust deposition is not the dominant source of iron to the large high-nutrient low-chlorophyll Southern Ocean.