Taking a spin on plasma space tornadoes:

Discussion in 'Astronomy, Exobiology, & Cosmology' started by paddoboy, Nov 17, 2017.

  1. paddoboy Valued Senior Member

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    Taking a spin on plasma space tornadoes with NASA observations
    November 17, 2017 by Mara Johnson-Groh

    Interplanetary space is hardly tranquil. High-energy charged particles from the Sun, as well as from beyond our solar system, constantly whizz by. These can damage satellites and endanger astronaut health—though, luckily for life on Earth, the planet is blanketed by a protective magnetic bubble created by its magnetic field. This bubble, called the magnetosphere, deflects most of the harmful high-energy particles.

    Nevertheless, some sneak through—and at the forefront of figuring out just how this happens is NASA's Magnetospheric Multiscale mission, or MMS. New results show that tornado-like swirls of space plasma create a boundary tumultuous enough to let particles slip into near Earth space.

    Read more at: https://phys.org/news/2017-11-plasma-space-tornadoes-nasa.html#jCp
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    the paper:

    https://www.nature.com/articles/s41467-017-01579-0

    Turbulent mass transfer caused by vortex induced reconnection in collisionless magnetospheric plasmas:

    Abstract
    Magnetic reconnection is believed to be the main driver to transport solar wind into the Earth’s magnetosphere when the magnetopause features a large magnetic shear. However, even when the magnetic shear is too small for spontaneous reconnection, the Kelvin–Helmholtz instability driven by a super-Alfvénic velocity shear is expected to facilitate the transport. Although previous kinetic simulations have demonstrated that the non-linear vortex flows from the Kelvin–Helmholtz instability gives rise to vortex-induced reconnection and resulting plasma transport, the system sizes of these simulations were too small to allow the reconnection to evolve much beyond the electron scale as recently observed by the Magnetospheric Multiscale (MMS) spacecraft. Here, based on a large-scale kinetic simulation and its comparison with MMS observations, we show for the first time that ion-scale jets from vortex-induced reconnection rapidly decay through self-generated turbulence, leading to a mass transfer rate nearly one order higher than previous expectations for the Kelvin–Helmholtz instability.

     

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