Dust from Patagonia to Kerguelen

REMI LOSNO; HEIMBURGER A; Z. QU; JOURNET E; MONNA F; EDUARDO QUEL; PABLO RISTORI; JACOBO SALVADOR; LIDIA OTERO; A. COGEZ; J. GAILLARDET; L. MEYNADIER; E. VIOLLIER; Y. BALKANSKI

Kiel Fjord

Conferencia; SOLAS Open Science Conference; 2015

International and interdisciplinary research project on biogeochemical-physical air-sea interactions and processes

The Southern Ocean is of paramount importance in the global carbon cycle due to its strong CO2 sink and its active export driven by its biological pump. Primary production by phytoplankton reduces the carbon dioxide to organic material which is partially buried into sediments. Supplying trace metals and metalloïds is essential to this biological pump because other nutrients, including nitrogen and phosphorus, are mostly non-limiting in this ocean. The atmosphere is suspected to be the main vector of micro-nutrients which are originating from continental dust emission by aeolian erosion of soils. Chemical and isotopic composition of dusts was measured at Kerguelen Island (South Indian Ocean) and compared to the chemical and the isotopic signature obtained from soils and aerosols in Patagonia. A strong contribution of Patagonian sources was detected at Kerguelen except during winter time when Southern African sources may be involved. This is consistent with an observed seasonality of dust emission in Patagonia showing a minimum during winter.