A plasmapause-like density boundary at high latitudes in Saturn's magnetosphere

作者：Gurnett D A^*; Persoon A M; Kopf A J; Kurth W S; Morooka M W; Wahlund J E; Khurana K K; Dougherty M K; Mitchell D G; Krimigis S M; Krupp N

来源：Geophysical Research Letters, 2010, 37: L16806.

DOI：10.1029/2010GL044466

Here we report the discovery of a well-defined plasma density boundary at high latitudes in Saturn's magnetosphere. The boundary separates a region of relatively high density at L less than about 8 to 15 from a region with densities nearly three orders of magnitude lower at higher L values. Magnetic field measurements show that strong field-aligned currents, probably associated with the aurora, are located just inside the boundary. Analyses of the anisotropy of energetic electrons show that the magnetic field lines are usually closed inside the boundary and open outside the boundary, although exceptions sometimes occur. The location of the boundary is also modulated at the similar to 10.6 to 10.8 hr rotational period of the planet. Many of these characteristics are similar to those predicted by Brice and Ioannidis for the plasmapause at a strongly magnetized, rapidly rotating planet such as Saturn. Citation: Gurnett, D. A., et al. (2010), A plasmapause-like density boundary at high latitudes in Saturn's magnetosphere, Geophys. Res. Lett., 37, L16806, doi:10.1029/2010GL044466.

• 出版日期2010-8-21