| Texto completo | |
| Autor(es): |
Raphaldini, Breno
[1]
;
Medeiros, Everton S.
[2]
;
Ciro, David
[3]
;
Franco, Daniel Ribeiro
[4]
;
Trindade, Ricardo I. F.
[5]
Número total de Autores: 5
|
| Afiliação do(s) autor(es): | [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
Número total de Afiliações: 5
|
| Tipo de documento: | Artigo Científico |
| Fonte: | PHYSICAL REVIEW RESEARCH; v. 3, n. 1 FEB 18 2021. |
| Citações Web of Science: | 0 |
| Resumo | |
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) | |
| Processo FAPESP: | 17/23417-5 - Variabilidade paleoclimática da Zona de Convergência do Atlântico Sul e processos no Oceano Atlântico e Pacífico: Último Glacial, Holoceno Médio e Último Milênio |
| Beneficiário: | Breno Raphaldini Ferreira da Silva |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |
| Processo FAPESP: | 18/03211-6 - Dinâmica não linear |
| Beneficiário: | Iberê Luiz Caldas |
| Modalidade de apoio: | Auxílio à Pesquisa - Temático |
| Processo FAPESP: | 13/26598-0 - Caracterização das Fronteiras entre Periodicidade e Caos no Espaço de Parâmetros |
| Beneficiário: | Everton Santos Medeiros |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |