Detecting Holocene Changes in the Atlantic Meridional Overturning Circulation: Integration of Proxy Data and Climate Simulations

Abstract

The contribution of central water circulation to the Atlantic Meridional Overturning Circulation (AMOC) and its role in natural climate variability remain poorly understood. Limits in our knowledge are due to the scarcity of high resolution records from central water depth and the limited abilities of proxy parameters to reconstruct small changes in Holocene central water properties. We addressed these issues by combining paleoclimate modeling of ‘fingerprints’ (UVic ESCM version 2.8) that identify suitable locations and parameters to reconstruct past central water variability with the development and application of a new Mg/Ca-paleotemperature calibration for the benthic foraminifera Hyalinea balthica. The presented records demonstrate the important role of central water circulation in communicating regional climate signatures of various forcings (freshwater flux, solar variability, orbital parameters) onto a hemispheric or global scale via cross-gyre meridional heat transfer from high to low latitudes.