| Full text | |
| Author(s): |
Raphaldini, Breno
[1]
;
Medeiros, Everton S.
[2]
;
Ciro, David
[3]
;
Franco, Daniel Ribeiro
[4]
;
Trindade, Ricardo I. F.
[5]
Total Authors: 5
|
| Affiliation: | [1] Univ Durham, Dept Math Sci, Upper Mountjoy Campus, Stockton Rd, Durham DH1 3LE - England
[2] Tech Univ Berlin, Inst Theoret Phys, Hardenbergstr 36, D-10623 Berlin - Germany
[3] Univ Fed Santa Catarina, Ctr Ciencias Biol, Florianopolis, SC - Brazil
[4] Observ Nacl, BR-04533085 Rio De Janeiro - Brazil
[5] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508090 Sao Paulo - Brazil
Total Affiliations: 5
|
| Document type: | Journal article |
| Source: | PHYSICAL REVIEW RESEARCH; v. 3, n. 1 FEB 18 2021. |
| Web of Science Citations: | 0 |
| Abstract | |
Geomagnetic field reversals remain as one of the most intriguing problems in geophysics and are regarded as chaotic processes resulting from a dynamo mechanism. In this article we use the polarity scale data of the last 170 Myrs collected from the ocean floor to provide robust evidence for an inverse relationship between the complexity of sequences of consecutive polarity intervals and the respective reversal rate. In particular, the variability of sequences of polarity intervals reaches minimum values in the mid-Jurassic when a maximum reversal rate is found, in the early Cretaceous preceding the Cretaceous Superchron, and twice in the last 20 Myrs. These facts raise the possibility of epochs of high regularity in the geomagnetic field reversals. To shed light on this process, we investigate the transition from regular to chaotic regime in a minimal model for geomagnetic reversals. We show that even in chaotic regimes, the system retains the signature of regular behavior near to transitions. We suggest that geomagnetic reversals have switched between different degrees of irregularity, with a dominant periodicity of approximate to 70 kyrs that results from the occurrence of ``ghost{''} limit cycles (GLCs) or unstable periodic orbits (UPOs) immersed in a chaotic region of phase space. (AU) | |
| 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 Opportunities: | Scholarships in Brazil - Post-Doctoral |
| FAPESP's process: | 18/03211-6 - Non linear dynamics |
| Grantee: | Iberê Luiz Caldas |
| Support Opportunities: | 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 Opportunities: | Scholarships in Brazil - Post-Doctoral |