FiniteLarmorradius equilibrium and currents of the Earth's flank magnetopause
Abstract
We consider the onedimensional equilibrium problem of a shearflow boundary layer within an `extendedfluid model' of a plasma that includes the Hall and the electron pressure terms in Ohm's law, as well as dynamic equations for anisotropic pressure for each species and firstorder finiteLarmorradius (FLR) corrections to the ion dynamics. We provide a generalized version of the analytic expressions for the equilibrium configuration given in Cerri et al., (Phys. Plasmas, vol. 20 (11), 2013, 112112), highlighting their intrinsic asymmetry due to the relative orientation of the magnetic field B, b = B/B, and the fluid vorticity ω = Δ × u('ωb asymmetry'). Finally, we show that FLR effects can modify the ChapmanFerraro current layer at the flank magnetopause in a way that is consistent with the observed structure reported by Haaland et al., (J. Geophys. Res. (Space Phys.), vol. 119, 2014, pp. 90199037). In particular, we are able to qualitatively reproduce the following key features: (i) the duskdawn asymmetry of the current layer, (ii) a doublepeak feature in the current profiles and (iii) adjacent current sheets having thicknesses of several ion Larmor radii and with different current directions.
 Publication:

Journal of Plasma Physics
 Pub Date:
 October 2018
 DOI:
 10.1017/S0022377818000934
 arXiv:
 arXiv:1804.02109
 Bibcode:
 2018JPlPh..84e5501C
 Keywords:

 space plasma physics;
 plasma flows;
 Physics  Space Physics;
 Physics  Plasma Physics
 EPrint:
 version accepted for publication in Journal of Plasma Physics