Magnetic reconnection is a fundamental plasma process that explosively converts magnetic energy into kinetic energy and heating of the plasma, and particle acceleration. Reconnection is a crucial mechanism in a variety of environments, from Earth’s and planetary magnetospheres to astrophysical systems. In near-Earth space, reconnection occurs in dynamic current sheets such as the magnetopause and the magnetotail, where it is often accompanied by plasma instabilities and wave generation. These instabilities, such as the electron firehose instability (EFI) and current sheet kink instability, can possibly influence the reconnection process. However, the interplay of reconnection and instabilities is still largely unexplored.
In this talk, I will present recent studies that explore the intricate interaction between reconnection and plasma instabilities at different scales in the Earth’s magnetotail.
We use 3D global hybrid-Vlasov simulations performed with the code Vlasiator to investigate how the current sheet kink instability interacts with reconnection in the magnetotail. Our results reveal that the kink instability can significantly perturb the current sheet, reducing the reconnection rate during the instability’s growth phase. These results highlight the intricate three-dimensional relationship between reconnection and kink instabilities, underlining their significant role in modulating the reconnection rate.
Magnetic reconnection is characterized by regions of enhanced temperature anisotropy that could drive instabilities such as EFI. Using high-resolution in situ observations from NASA’s Magnetospheric Multiscale (MMS) mission, we identified and characterized fluctuations generated by EFI in the reconnection outflow. These observations provide the first direct evidence of EFI waves during reconnection and highlight their possible role in modulating the global energy conversion associated with reconnection.
By combining in situ spacecraft data and simulations, these studies provide new insights on the interaction of reconnection and instabilities, advancing our understanding of fundamental plasma processes in Earth’s magnetotail and beyond.
Zoom link : https://cnrs.zoom.us/j/95003883304?pwd=MI0B5WLYiGZlzo3oAZUl5TAu4fta6q.1
