Assessing changes in North Atlantic Central Water-mass properties during the Holocene

Abstract

Eastern North Atlantic Central Water formation and circulation are linked to the strength of the Atlantic Meridional Overturning Circulation (AMOC) and therefore an important component of our climate system. Today, the North Atlantic Oscillation is one of the controlling modes in climate variability of atmosphere-ocean linkages over the subpolar and subtropical basins and influences central water formation and circulation. However, the impact of longer-term forcings such as total solar irradiance, sudden or gradual changes in the freshwater budget of the North Atlantic, and the nature of climate signal propagation from high to low latitudes within central water circulation remains poorly understood. This thesis presents a newly developed Mg/Ca temperature calibration of the calcitic benthic foraminifera Hyalinea balthica, which allows the reconstruction of decadal to centennial scale climate variability in Eastern North Atlantic Central Water during the Holocene.