The Impact of Turbulence on Physics of the Geomagnetic Tail

Elizaveta E Antonova,Marina V Stepanova

doi:10.3389/fspas.2021.622570

Elizaveta E Antonova, Marina V Stepanova

Open Access

https://doi.org/10.3389/fspas.2021.622570

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Abstract

There is a vast amount of evidence that suggests that the geomagnetic tail is like a turbulent wake behind an obstacle. Large-scale vortices in the wake are able to generate turbulent transport that takes place both along the plasma sheet, in the X and Y directions, and across the plasma sheet, in the Z direction. Thus, turbulent fluctuations in all directions should be taken into consideration when analyzing plasma transport in the plasma sheet, and stability of the plasma sheet configurations. In this review, we summarize and discuss the main results of large and middle scale magnetospheric turbulence yielded by data analysis and modeling. We also identify changes in the description of the magnetospheric dynamics connected with the existence of turbulent fluctuations in the tail.

Highlights

Formation of turbulent wake behind an obstacle is a well-known phenomenon observed in the gas and fluid flows with a high Reynolds number
Our analysis shows that mechanisms of generation of the plasma sheet turbulence are deeply connected to the plasma pressure gradients in the magnetosphere, including the driving or integral scale vortices–the two-vortex convection and the eddy vortices, responsible for the eddy diffusion transport
We have summarized published results in which the plasma sheet in Earth’s magnetosphere has been regarded as a turbulent wake behind an obstacle formed due to high Reynolds number values

Summary

Introduction

Formation of turbulent wake behind an obstacle is a well-known phenomenon observed in the gas and fluid flows with a high Reynolds number. When the computer codes combine both the low resistivity and small grid spacing, it is possible to obtain comparatively large values of the magnetic Reynolds number and to model the formation of the turbulent plasma sheet under idealized southward (El-Alaoui et al, 2010) and northward (El-Alaoui et al, 2012) IMF.

Results

Conclusion