Conférence de monsieur Roger François
Le 24 novembre 2010 à 10 h 15
Salle Mohammed-El-Sabh (P-210)
Sediment 231Pa/230Th as a recorder of the rate of the Atlantic meridional overturning circulation : Insights from a 2-D model
Dissolved 230th was first measured in the water column of the Arctic Ocean in 1983 from an ice camp over Alpha Ridge. Subsequently, an additional 22 profiles were measured at various locations between 1987 and 2009 in the Eurasian and Canadian Basins. These proliles can be compared in space and time to infer changes in the deep water circulation of the Arctic Ocean. In the mid-1900’s, the pattern of Arctic deep water circulation started to change, resulting in the displacement of a previously isolated water mass into the surrounding basins, first in the Norwegian Sea, and most recently in Canada Basin. These data further illustrate the potential of 230Th as a powerful, yet rarely used, tracer of deep water circulation.
Dernier ajout: lundi 26 mars 2012