Collisionless reconnection in Jupiter's magnetotail
Abstract
We present the first quantitative study of collisionless reconnection in Jupiter's magnetotail. Recently it has been shown that collisionless reconnection can occur in the Earth's magnetotail quasi-neutral sheet when the electrons are subject to chaotic pitch angle diffusion. This happens when the magnetic field is very taillike, i.e., when the curvature parameter κe = Bz/B0(Lz/ρe0)1/2 decreases to ≈ 1.6. For Jupiter's magnetotail, a self-consistent axisymmetric equilibrium model is used to compute the magnetic field and κe, and it is found that the condition for electron chaotization is satisfied in a region large enough to allow the growth of a tearing instability. The favourite site for reconnection is situated at about 60 RJ, and the growth time is estimated to be about 370 s, i.e., much shorter than the plasma transit time through the chaotization region. The inductive e.m.f. along a 20 RJ X line is estimated to be of order 100kV - 1 MV, and should accelerate the ions dawnward and the electrons duskward.
- Publication:
-
Geophysical Research Letters
- Pub Date:
- April 1991
- DOI:
- 10.1029/91GL00472
- Bibcode:
- 1991GeoRL..18..741Z
- Keywords:
-
- Jupiter Atmosphere;
- Magnetic Field Reconnection;
- Neutral Sheets;
- Planetary Magnetospheres;
- Planetary Magnetotails;
- Current Sheets;
- Electron Acceleration;
- Magnetic Field Configurations;
- Tearing Modes (Plasmas);
- JUPITER;
- MAGNETOSPHERE;
- MAGNETOTAIL;
- DISCONNECTION;
- MAGNETIC FIELD;
- MODELS;
- TIMESCALE;
- ELECTRONS;
- CHAOS;
- IONS;
- ACCELERATION;
- CALCULATIONS;
- PARAMETERS;
- DISTANCE;
- STABILITY;
- ENERGY;
- ELECTRICAL FIELD;
- PLASMA;
- DYNAMICS;
- MOTION;
- VELOCITY;
- Lunar and Planetary Exploration; Jupiter;
- Magnetospheric Physics: Planetary magnetospheres;
- Space Plasma Physics: Magnetic reconnection;
- Space Plasma Physics: Charged particle motion and acceleration