The Time-Dependent Paleocirculation Problem


OCCI Funded Project: 2006

Proposed Research

In this project we will develop an inverse method to interpret the time-dependent information that is contained in two sediment records originating from the North Atlantic (one from the western basin and one from the eastern basin) and covering the last deglaciation. The records are time series of the ratio between two naturally-occurring radio-isotopes (protactinium-231 and thorium-230), which has been hypothesized to provide constraints on the strength of the meridional overturning circulation in the North Atlantic. We will test the null hypothesis (H0 hereafter) that the Pa-231/Th-230 records are consistent with an estimate of the abyssal circulation based on modern hydrography, the existing database of Pa-231 and Th-230 measurements in the water column and surface sediments, and geostrophic dynamics. If the circulation did change within the time span of the records and if the sediment data are adequate, one should be able to reject H0.