Funds are provided to support two related foci of this project ? analytical studies of ocean circulation and paleo-oceanographic estimation of transport variability. The PI will analyze diffuse spectral reflectance and X-Ray Fluorescence (XRF) data as proxies for sediment provenance, and grain size variation in samples taken from both sides of the Bering Strait (BST) as a proxy for paleo-current strength. In parallel, the analytical focus of the co-PI will be to develop a time-dependent version of the steady state models of flow through BST that he has previously developed. Together, they will then compare periods of high and low global wind fields with weak or strong Atlantic Meridional Overturning Circulation (AMOC) to periods of strong or weak flows at the BST. They already have one excellent example for the success of such an approach. About 5000 years ago the Southern Ocean winds weakened significantly and, simultaneously (geologically speaking) the flow through the BST increased and the AMOC weakened, in an excellent conceptual agreement with their preliminary analytics. Their cross-discipline collaboration will benefit physical oceanography by providing ?natural experiments? that are otherwise unavailable, and benefit paleo-oceanography by providing dynamical explanations for the past oceanographic changes observed in proxy data.
