# Modeling the Dynamics of Glacial Cycles

## TL;DR

This paper analyzes a conceptual model of glacial cycles, demonstrating how simplified versions capture key dynamics like limit cycles and bifurcations, highlighting the role of atmospheric CO2 in glacial periodicity.

## Contribution

It introduces a simplified two-dimensional model that retains essential features of the original three-dimensional system, elucidating the dynamics of glacial cycles.

## Key findings

- The simplified model exhibits equilibrium states and limit cycles similar to the full model.
- Identification of bifurcations and a Bogdanov-Takens point as organizing centers.
- Symmetry breaking leads to splitting of the Bogdanov-Takens point with different local dynamics.

## Abstract

This article is concerned with the dynamics of glacial cycles observed in the geological record of the Pleistocene Epoch. It focuses on a conceptual model proposed by Maasch and Saltzman [J. Geophys. Res.,95, D2 (1990), pp. 1955-1963], which is based on physical arguments and emphasizes the role of atmospheric CO2 in the generation and persistence of periodic orbits (limit cycles). The model consists of three ordinary differential equations with four parameters for the anomalies of the total global ice mass, the atmospheric CO2 concentration, and the volume of the North Atlantic Deep Water (NADW). In this article, it is shown that a simplified two-dimensional symmetric version displays many of the essential features of the full model, including equilibrium states, limit cycles, their basic bifurcations, and a Bogdanov-Takens point that serves as an organizing center for the local and global dynamics. Also, symmetry breaking splits the Bogdanov-Takens point into two, with different local dynamics in their neighborhoods.