Science and Technology Production
2nd AMS-UMI Joint International Meeting 2024 - Nonautonomous Dynamical Systems for Climate Change & Climate Variability: An Application to a Simple Ocean Model

Congress

Authorship
Ghil, Michael ; CHARÓ, GISELA DANIELA ; Denisse Sciamarella ; Pierini, Stefano
Date
2025
Publishing House and Editing Place
American Mathematical Society
Summary Information provided by the agent in SIGEVA
The theory of nonautonomous and random dynamical systems (NDSs and RDSs) provides an appropriate mathematical setting for the study of time-dependent forcing, both natural and anthropogenic, upon a climate system characterized by intrinsic variability [1]. In this theory, the forward attractors of autonomous dynamical systems are replaced by pullback and random attractors (PBAs and RAs) and classical bifurcations by “tipping points.” Over the last decade- and-a-half, these relativel... The theory of nonautonomous and random dynamical systems (NDSs and RDSs) provides an appropriate mathematical setting for the study of time-dependent forcing, both natural and anthropogenic, upon a climate system characterized by intrinsic variability [1]. In this theory, the forward attractors of autonomous dynamical systems are replaced by pullback and random attractors (PBAs and RAs) and classical bifurcations by “tipping points.” Over the last decade- and-a-half, these relatively novel concepts have been applied to a number of simple climate models, atmospheric, oceanic and coupled [2]. Important insights into the study of PBAs and RAs arising from climate dynamics have been provided by novel tools from algebraic topology [3,4]. These tools have led to the introduction and analysis of topological tipping points and we present them here as applied to a simple model of the wind-driven double-gyre ocean circulation [5]. The model is a low-order approximation of a spectral quasigeostrophic model for the sub- tropical and subpolar gyres of the North Atlantic or North Pacific ocean basin, subject to time varying zonal winds [6]. The recent tools from algebraic topology applied to it are Branched Manifold Analysis through Homologies (BraMAH) and the Templex, which combines the com- plex underlying BraMAH with a directed graph that captures the flow in the dynamical system’s phase space [4].
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Key Words
TEMPLEXPULLBACK ATTRACTORSDOUBLE GYRE