Model for the coupling of turbulence and zonal flows and fields in the ionosphere

The coupling of turbulence and zonal flows in toroidal plasmas is well known and presents interesting physics which leads to improved confinement scenarios. When magnetic fluctuations are also important there is a self organization that leads to the appearance of large scale zonal fields. In the ionosphere, on the other hand, MHD fluctuations are always present and they can couple to the Earth rotation to give rise to large scale geostrophic flows. This has been studied for the case of Rossby waves which present a situation analogous to drift waves in magnetized toroidal plasmas. Now, when the Earth magnetic field is also taken into account in addition to the zonal flows the appearance of a zonal field is possible. This has been studied by Kaladze el al. [1] in a model that considers a combination of Rossby-Alfvén-Khantadze waves showing the emergence of zonal flows and fields. In the present work we present a model based in [1] that extends the interaction of turbulence and large scale features to a complete two-way coupling. The model is applicable to the E-layer of the ionosphere and it is based on the momentum equations for ions and electrons. They are combined and separated in large and small scales in order to obtain a set of four coupled equations for the time evolution of the energies of the velocity and magnetic fluctuations as well as equations for the zonal flows and fields. They are solved to show the coupling between the four quantities which present an interesting self-organized behavior.

[1] T.D. Kaladze et al. Phys. Scr. 88 (2013) 06550.