1. The Magnetosphere
Feifei Jiang, UCLA

2. Outline
Magnetic field
Plasmas
Currents
Force Balance

3. The Earth’s Main Field Dipole in spherical coordinates L L0
Dipole field lines

4. The Stretched Tail
Magnetic Reconnection
Viscous Interaction

5. The Tail Plasma Sheet Plasma parameters in the central plasma sheetB
N = 0.1~0.5 cm-3
Ti = 2~10 keV
Ti/Te = 6
EXB
Mantle particles will ExB drift towards the center of the tail
To move from the center of mantle to the center of plasma sheet

6. The Radiation Belts One proton belt: 0.1~ 100 MeV, peak near L~1.8
Two electron belts with a slot region:
For E> 1 MeV peak near L=1.6 and 4.0 Re
Source: ~keV particles in the plasma sheet
How are these particles energized?
1. Acceleration by chorus waves
2. Radial diffusion
3. Substorm injection

7. The Plasmasphere Guiding center drift velocity Cold, dense plasmas:
~103 cm-3, ~1 eV
Plasmapause, 3~5 Re depending on geomagnetic activity
2 sources: Polar wind and convection
Stagnation Point

8. Currents in the Magnetosphere

9. Magnetopause Current
The current crossing y=y0 per unit length in z

10. Tail Current

11. Field-aligned current
Region 1 current:
Flow shear/parallel flow vorticity
Region 2 current:
surfaces of constant pressure are not aligned with magnetic shells

12. Ring Current Dessler-Parker-Sckopke relationship
Magnetic field of a current loop
Dessler-Parker-Sckopke relationship

13. Force Balance K=0.89, a ~ 2.4 At the magnetopause nose
At the magnetopause on the tail side
At the tail plasma sheet

14. Thank you

15. Particle Motion in the Magnetosphere