Collaborative Research: Modeling the Role of Obliquity and Insolation Gradients in Controlling Global Ice Volume

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

The goal of this research is to construct a series of process models to examine the transport of heat and moisture from low to high latitudes in the atmosphere and oceans and their interactions with ice sheets. The central thesis of the research is that the Earth's obliquity controls the differential of insolation between high and low latitudes and, hence, ice volume and climate. Milankovitch theory postulates that ice-age cycles are controlled by insolation in high northern latitudes in summer. This insolation is dominated by the 23,000-year period of the precession cycle. Paleoclimate evidence, however, indicates that the dominant period in ice volume over the last three million years is the 41,000-year period of obliquity. This discrepancy represents a crucial gap in understanding in the science of paleoclimatology. Validating the insolation gradient hypothesis would greatly advance our understanding of Earth's past climate history. Since no climate model has yet succeeded in reproducing the record of the ice ages, the knowledge gained in validating the hypothesis would also point the way towards constructing climate models with greater reliability for predicting future climate changes. Funding is primarily for the support of a graduate student who would carry out the proposed research as part of a doctoral research project.