| Texto completo | |
| Autor(es): |
Número total de Autores: 4
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| Afiliação do(s) autor(es): | [1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508090 Sao Paulo - Brazil
[2] Univ Wisconsin, Dept Astron, Madison, WI 53706 - USA
[3] McMaster Univ, Dept Phys & Astron, Hamilton, ON L8S 4M1 - Canada
[4] Jagiellonian Univ, Astron Observ, PL-30244 Krakow - Poland
Número total de Afiliações: 4
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| Tipo de documento: | Artigo Científico |
| Fonte: | Nonlinear Processes in Geophysics; v. 19, n. 2, p. 297-314, 2012. |
| Citações Web of Science: | 41 |
| Resumo | |
We study a model of fast magnetic reconnection in the presence of weak turbulence proposed by Lazarian and Vishniac (1999) using three-dimensional direct numerical simulations. The model has been already successfully tested in Kowal et al. (2009) confirming the dependencies of the reconnection speed V-rec on the turbulence injection power P-inj and the injection scale l(inj) expressed by a constraint V-rec similar to P(inj)(1/2)l(inj)(3/4)and no observed dependency on Ohmic resistivity. In Kowal et al. (2009), in order to drive turbulence, we injected velocity fluctuations in Fourier space with frequencies concentrated around k(inj) = 1/l(inj), as described in Alvelius (1999). In this paper, we extend our previous studies by comparing fast magnetic reconnection under different mechanisms of turbulence injection by introducing a new way of turbulence driving. The new method injects velocity or magnetic eddies with a specified amplitude and scale in random locations directly in real space. We provide exact relations between the eddy parameters and turbulent power and injection scale. We performed simulations with new forcing in order to study turbulent power and injection scale dependencies. The results show no discrepancy between models with two different methods of turbulence driving exposing the same scalings in both cases. This is in agreement with the Lazarian and Vishniac (1999) predictions. In addition, we performed a series of models with varying viscosity nu. Although Lazarian and Vishniac (1999) do not provide any prediction for this dependence, we report a weak relation between the reconnection speed with viscosity, V-rec similar to nu(-1/4). (AU) | |
| Processo FAPESP: | 09/50053-8 - Magnetic reconnection and particle acceleration in astrophysical sources and diffuse media |
| Beneficiário: | Grzegorz Kowal |
| Modalidade de apoio: | Bolsas no Brasil - Pós-Doutorado |