Nonlinear time series analysis of palaeoclimate proxy records

Identifying and characterising dynamical regime shifts, critical transitions or potential tipping points in palaeoclimate time series is relevant for improving the understanding of often highly nonlinear Earth system dynamics. Beyond linear changes properties such as mean, variance, trend, these shifts can manifest signal predictability, regularity, complexity, higher-order stochastic multi-stability. In recent years, several classes methods have been put forward to study data that are based on concepts from dynamics, complex systems science, information theory, analysis. These include approaches phase space-based recurrence plots networks, visibility graphs, order pattern-based entropies, modelling. Here, we review compare detail prominent fields by applying them same set marine proxy records African climate variations during past 5 million years. Applying methods, observe notable dynamics discuss context important events regimes phases intensified Walker circulation, isotope stage M2, onset northern hemisphere glaciation mid-Pleistocene transition. We find studied complement each other allowing us point out distinct aspects series. also detect significant correlations shift indicators with Earth's orbit, suggesting latter triggers palaeoclimate. Overall, presented underlines potentials analysis provide complementary their driving processes cannot be revealed statistics eyeball inspection alone.