A tale of two vortices: How numerical ergodic theory and transfer operators reveal fundamental changes to coherent structures in non-autonomous dynamical systems

dc.contributor.authorBlachut, C.
dc.contributor.authorGonzález-Tokman, C.
dc.date.issued2020
dc.description.abstractCoherent structures are spatially varying regions which disperse minimally over time and organise motion in non-autonomous systems. This work develops and implements algorithms providing multilayered descriptions of time-dependent systems which are not only useful for locating coherent structures, but also for detecting time windows within which these structures undergo fundamental structural changes, such as merging and splitting events. These algorithms rely on singular value decompositions associated to Ulam type discretisations of transfer operators induced by dynamical systems, and build on recent developments in multiplicative ergodic theory. Furthermore, they allow us to investigate various connections between the evolution of relevant singular value decompositions and dynamical features of the system. The approach is tested on models of periodically and quasi-periodically driven systems, as well as on a geophysical dataset corresponding to the splitting of the Southern Polar Vortex.
dc.description.statementofresponsibilityChantelle Blachut and Cecilia González-Tokman
dc.identifier.citationJournal of Computational Dynamics, 2020; 7(2):369-399
dc.identifier.doi10.3934/jcd.2020015
dc.identifier.issn2158-2491
dc.identifier.issn2158-2505
dc.identifier.orcidBlachut, C. [0000-0001-9955-7682]
dc.identifier.urihttps://hdl.handle.net/2440/139969
dc.language.isoen
dc.publisherAmerican Institute of Mathematical Sciences (AIMS)
dc.relation.granthttp://purl.org/au-research/grants/arc/DE160100147
dc.rights©American Institute of Mathematical Sciences
dc.source.urihttps://doi.org/10.3934/jcd.2020015
dc.subjectNumerical ergodic theory; non-autonomous dynamical systems; coherent structures; transfer operators; Ulam’s method
dc.titleA tale of two vortices: How numerical ergodic theory and transfer operators reveal fundamental changes to coherent structures in non-autonomous dynamical systems
dc.typeJournal article
pubs.publication-statusPublished

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