North Atlantic ocean circulation during the last glacial maximum and subsequent meltwater event: A numerical model

Abstract

A numerical model that was forced with reconstructed sea surface temperature and sea surface salinity values of the North Atlantic was used to investigate three major states of the North Atlantic ocean circulation since the last glaciation: the modern state, the last glacial maximum (LGM), and an important meltwater event (MWE) near 14,200–13,200 14 C yr B.P. Preliminary results of numerical experiments show significant differences of the three outlined modes in the northern North Atlantic and especially in the Norwegian Greenland Seas (NGS). The overturning strength of the North Atlantic salinity conveyor belt and northward heat transport decreased somewhat in the LGM and drastically in the MWE case. Accordingly, the North Atlantic Deep Water production decreased by 30% during the LGM and almost ceased at the MWE. The climatologically most important changes occurred during the MWE and are characterized by a reversal in the circulation of the surface water in the northeastern part of the NGS, implying that the North Atlantic Current did not reach the Norwegian Sea anymore.