Articles | Volume 10, issue 4/5
Nonlin. Processes Geophys., 10, 351–361, 2003
https://doi.org/10.5194/npg-10-351-2003

Special issue: Theory and Simulation of Solar System Plasmas, No.4

Nonlin. Processes Geophys., 10, 351–361, 2003
https://doi.org/10.5194/npg-10-351-2003

  31 Oct 2003

31 Oct 2003

On the predominance of oblique disturbances in the supersonic shear flow instability of the geomagnetic tail boundary

V. V. Mishin V. V. Mishin
  • Institute of Solar-Terrestrial Physics Russian Academy of Sciences, P.O. Box 4026, Irkutsk 664033, Russia

Abstract. A study is made of the influence of the longitudinal magnetic field and density inhomogeneity on the supersonic shear flow instability at the magnetospheric tail boundary. It is shown that the most unstable are slow oblique (3D) disturbances, with a phase velocity approaching at a sufficiently large angle (with respect to the flow direction) the magnetosonic velocity. Their growth rate and spectral width are much larger than those of the usually considered longitudinal (2D) supersonic disturbances. The magnetic field reduces the compressibility effect and, unlike the subsonic case, has a noticeable destabilizing effect on the excitation of oblique disturbances.