Seminari del Dipartimento

 

Fisica

The terrestrial and solar dynamos: effects of anisotropic magnetic diffusivity on rotating magnetoconvection

Enrico Filippi


08-01-2018 - 16:00
Via della Vasca Navale 84 - AULA A

 

This talk briefly recall the basics of the Dynamo Theory of the Planetary and Solar Magnetic Fields. Then, some results indicate the importance of the anisotropic magnetic diffusivity of the Earth’s Outer Core due to its turbulent state. For instance, Filippi et al., (2015) stated that the relaxation times of the Geomagnetic field dipole component in the last few millennia are much faster than those typically obtained by a simple magnetic diffusion in the geodynamo. That indicated that if the turbulence increases the magnetic diffusivity then the assumption of even anisotropic magnetic diffusivity is possible. Therefore, a former model (Šoltis and Brestenský, 2010) about anisotropy in Rotating Magnetoconvection is extended and the advancements will be described.
Then, the structure and the analysis of  this model will be used  to investigate the solar dynamo and more specifically the (likely) anisotropy in the convection zone of the Sun. Besides, the possibility to compare the Earth and Solar dynamo problems with some studies on the geomagnetic external sources   will be also discussed.

References
1.    Filippi, E., A. De Santis, F.J. Pavón-Carrasco, B. Duka and K.Peqini, Some evidence for a Turbulent Diffusion in the Geodynamo from geomagnetic global models of the last few millennia, *26th IUGG General Assembly*, Prague, 2015 (available at https://drive.google.com/file/d/0B-vFmSm_gnQfNFhTcTRrUEVXbHM/view?pref=2&pli=1)
2.    Šoltis, T., Brestenský, J., Rotating magnetoconvection with anisotropic diffusivities in the Earth’s core, *Phys. Earth Planet. Inter.*, 178, 27–38, 2010.
 
org: ORESTANO Domizia

 

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