On the relationship between Nd isotopic composition and ocean overturning circulation in idealized freshwater discharge events ...

• Main Authors: Rempfer, Johannes, Dutay, Jean-Claude, Joos, Fortunat, Stocker, Thomas F.
• Format: Article in Journal/Newspaper
• Language: English
• Published: American Geophysical Union 2012
• Subjects: Antarc*; Antarctic; NADW; North Atlantic Deep Water; North Atlantic; Southern Ocean
• Online Access: https://dx.doi.org/10.7892/boris.18179; http://boris.unibe.ch/18179/

Using a cost-efficient climate model, the effect of changes in overturning circulation on neodymium isotopic composition,ϵNd, is systematically examined for the first time. Idealized sequences of abrupt climate changes are induced by the application of periodic freshwater fluxes to the North Atlantic (NA) and the Southern Ocean (SO), thus mainly affecting either the formation of North Atlantic Deep Water (NADW) or Antarctic Bottom Water (AABW). Variations in ϵNd reflect weakening and strengthening of the formation of NADW and AABW, changes in ϵNdof end-members are relatively small. Relationships betweenϵNd and the strength of NADW or AABW are more pronounced for AABW than for NADW. Atlantic patterns of variations in ϵNd systematically differ between NA and SO experiments. Additionally, the signature of changes in ϵNd in the Atlantic and the Pacific is alike in NA but opposite in SO experiments. Discrimination between NA and SO experiments is therefore possible based on the Atlantic pattern of variations in ...