Glacial Cycles and Milankovitch Forcing

TL;DR

This paper presents a conceptual model linking Milankovitch cycles, especially obliquity and eccentricity, to the timing of glacial and interglacial periods, supporting their role as triggers for ice sheet dynamics.

Contribution

It introduces a finite-dimensional approximation of a complex climate model that explicitly incorporates Milankovitch cycles to explain glacial cycles.

Findings

Deglaciation and glaciation are primarily driven by Earth's obliquity.

Eccentricity also influences glacial cycles but to a lesser extent.

The model aligns well with observed timing of glacial periods.

Abstract

Using a recent conceptual model of the glacial-interglacial cycles we present more evidence of Milankovitch cycles being the trigger for retreat and forming of ice sheets in the cycles. This model is based on a finite approximation of an infinite dimensional model which has three components: Budyko's energy balance model describing the annual mean temperatures at latitudes, Widiasih's ODE which describes the behavior of the edge of the ice sheet, and Walsh et al. who introduced a snow line to account for glacial accumulation and ablation zones. Certain variables in the model are made to depend on the Milankovitch cycles, in particular, the obliquity of the Earth's axis and the eccentricity of the Earth's orbit. We see as a result that deglaciation and glaciation do occur mostly due to obliquity and to some extent eccentricity.