Modeling Ice Sheet Evolution on Orbital and Millennian Timescales

Investigator: Peter U. Clark clarkp@ucs.orst.edu  (Principal Investigator current)          Steven W. Hostetler  (Co-Principal Investigator current)

Abstract

This award supports  a collaborative project whose principal objective is to model the origin of orbital- and millennial-scale  variability of ice sheets.  The project will focus on the inception of the North Hemisphere ice sheets the origin of the lOO-kyr ice volume signal in the absence of significant orbital forcing at that frequency ice-sheets dynamics that give rise to Heinrich events, and the role of ice sheets in D/O events, initially the project will focus on the North American ice sheets although the resulting model will be applicable to Eurasian ice sheets. The modeling strategy is guided by the overarching hypothesis that orbital- arid millennial-scale variability of ice sheets is strongly influenced by hydrologic, geologic and atmospheric conditions, and that the neglect of these conditions is a fundamental source of deficiency in existing ice-sheet models. The project will enhance an existing three-dimensional (3-ft) ice-sheet model developed by the participants by adding components to simulate ice streams ice shelves, and ice calving along marine margins and proglacial lakes Throughout the simulations, the geological record will be used to validate model output and guide model modifications