Start Date: 2010-12-02 End Date: 2013-02-12
Plasma vortices are often detected by spacecraft in
the geospace (atmosphere, ionosphere, magnetosphere) environment, for instance in the magnetosheath and in the magnetotail region. Large scale vortices may correspond to the
injection scale of turbulence, so that understanding their origin is important for understanding the energy transfer processes in the geospace environment. In a recent work, turbulent state of plasma medium (especially, ionosphere) is
overviewed. Experimental observation data from THEMIS
mission (Keiling et al., 2009) is investigated and numerical
simulations are carried out. By analyzing the THEMIS data
for that event, we find that several vortices in the magnetotail
are detected together with the main one and these vortices
constitute a vortex chain. Such vortices can cause the strong
turbulent state in the different media. The strong magnetic
turbulence is investigated in the ionsophere as an ensemble of
such strongly localized (weakly interacting) vortices. Characteristics of power spectral densities are estimated for the
observed and analytical stationary dipole structures. These
characteristics give good description of the vortex structures.