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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Evidence for crisis-induced intermittency during geomagnetic superchron transitions

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Author(s):
Raphaldini, Breno [1] ; Ciro, David [1] ; Medeiros, Everton S. [2] ; Massaroppe, Lucas [1] ; Trindade, Ricardo I. F. [1]
Total Authors: 5
Affiliation:
[1] Univ Sao Paulo, Inst Astron Geophys & Atmospher Sci, Rua Matao 1226, BR-05508090 Sao Paulo, SP - Brazil
[2] Univ Sao Paulo, Inst Phys, Rua Matao 187, BR-05508090 Sao Paulo, SP - Brazil
Total Affiliations: 2
Document type: Journal article
Source: Physical Review E; v. 101, n. 2 FEB 12 2020.
Web of Science Citations: 0
Abstract

The geomagnetic field's dipole undergoes polarity reversals in irregular time intervals. Particularly long periods without reversals (of the order of 10(7) yr), called superchrons, have occurred at least three times in the Phanerozoic (since 541 million years ago). We provide observational evidence for high non-Gaussianity in the vicinity of a transition to and from a geomagnetic superchron, consisting of a sharp increase in high-order moments (skewness and kurtosis) of the dipole's distribution. Such an increase in the moments is a universal feature of crisis-induced intermittency in low-dimensional dynamical systems undergoing global bifurcations. This implies a temporal variation of the underlying parameters of the physical system. Through a low-dimensional system that models the geomagnetic reversals, we show that the increase in the high-order moments during transitions to geomagnetic superchrons is caused by the progressive destruction of global periodic orbits exhibiting both polarities as the system approaches a merging bifurcation. We argue that the non-Gaussianity in this system is caused by the redistribution of the attractor around local cycles as global ones are destroyed. (AU)

FAPESP's process: 18/03211-6 - Non linear dynamics
Grantee:Iberê Luiz Caldas
Support type: Research Projects - Thematic Grants
FAPESP's process: 15/50686-1 - Paleo-constraints on monsoon evolution and dynamics
Grantee:Pedro Leite da Silva Dias
Support type: Research Projects - Thematic Grants
FAPESP's process: 13/26598-0 - Fractal Boundaries between chaos and periodicity in the parameters space.
Grantee:Everton Santos Medeiros
Support type: Scholarships in Brazil - Post-Doctorate
FAPESP's process: 17/23417-5 - Paleoclimatic variability of South Atlantic Convergence Zone and processes in the Atlantic and Pacific Oceans: Last Glacial, Middle Holocene and Last Millennium
Grantee:Breno Raphaldini Ferreira da Silva
Support type: Scholarships in Brazil - Post-Doctorate