Response of a zonal climate- ice sheet model to the orbital perturbations during the Quaternary ice ages.

The astronomical theory of the ice ages is investigated using a simple climate model which includes the ice sheets explicitly. Model ice age curves are generated for the last several 10 Kyr by computing the seasonal climate as above once every 2Kyr, with isolation calculated from actual Earth orbit perturbations. The sensitivity of the model ice age curves to various parameter changes is described, but none of these changes significantly improve the fit of the model ice age curves to the data. In the concluding section we generalize about the types of mechanisms that might yield realistic glacial-interglacial cycles. -Authors