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Accueil > A propos du LPP > Communication > Actualités archivées > 2015 > Journal of Plasmas’ cover shows results from a team comprising LPP scientists

Journal of Plasmas’ cover shows results from a team comprising LPP scientists

Turbulence is a universal phenomenon occurring in fluids as well as in magnetized collisionless plasma. This work focuses on the spontaneous development of turbulence in the saturated phase of the Kelvin-Helmholtz (K-H) instability using a Two-Fluid simulation.
The physical reference is the low latitude Earth’s magnetopause where the shear flow between solar wind and magnetosphere plasmas provides the conditions for this instability to develop and to create a chain of large scale vortices. The development of the K-H instability is particularly important in terms of solar wind plasma transport into the Earth’s magnetosphere.
During the evolution of the instability, the vortices evolve nonlinearly and interact one with each other leading to merging or being disrupted. The vortices disruption is driven by the development of secondary instabilities around the edge of the arms of the vortices, in between or inside the vortices themselves.

JPEG - 1.2 Mo

In this figure the iso-contours of the out of plane current Jz (x,y) with the magnetic potential lines are drawn, taking a zoom in the saturated phase of the instability.
This turbulent region is characterized by the presence of small scale magnetic field fluctuations and structures of the order of one inertial length or less. The authors observed the presence of intermittency and studied the intense structures responsible for intermittency. They noticed that these structures are consistent with reconnecting current sheets. The detailed analysis of one reconnection structure shows reconnection rates higher than values typically recovered in Hall reconnection but in agreement with other simulations of reconnection in a turbulent medium.

View article : C. Rossi et al


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Tutelles : CNRS Ecole Polytechnique Sorbonne Université Université Paris Sud Observatoire de Paris Convention : CEA
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Directeur de la publication : Pascal Chabert (Directeur)