Accueil > Actualités > Séminaires > Séminaire de Guy Williams


Titre : The suppression of Antarctic Bottom Water formation by melting ice shelves in Prydz Bay
Nom du conférencier : Guy Williams
Son affiliation : IMAS (Hobart, Tasmania)
Laboratoire organisateur : LOCEAN
Date et heure : 30-05-2016 11h00
Lieu : UPMC - 4 place Jussieu - Paris 5e - LOCEAN, tour 45/55, 4eme étage - salle de réunion
Résumé :

A fourth production region for the globally important Antarctic Bottom Water has been attributed to Dense Shelf Water formation in the Cape Darnley Polynya, adjoining Prydz Bay in East Antarctica. Extensive new observations from CTD-instrumented elephant seals in 2011-2013 now provides the first complete assessment of Dense Shelf Water formation in Prydz Bay. After a complex evolution involving the opposing contributions of three polynyas (positive) and two ice shelves (negative), Dense Shelf Water (salinity 34.65–34.7) is exported through Prydz Channel. This provides a distinct, relatively fresh contribution to Cape Darnley Bottom Water. Elsewhere, dense water formation is hindered by the freshwater input from the Amery and West Ice Shelves into the Prydz Bay Gyre. This study highlights the susceptibility of Antarctic Bottom Water to increased freshwater input from the enhanced melting of ice shelves, and ultimately the potential collapse of Antarctic Bottom Water formation in a warming climate.

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