SLIDE 1 Polar observations of the characteristics of the dayside high altitude cusp
- T. A. FRITZ, J. CHEN, J. NIEHOF
Center for Space Physics at Boston University
Polar PI conference call December 3, 2004
SLIDE 2 The Chapman Ferraro Cusp
Observationally Polar has shown that the cusp is a large region and is the site
fluxes of energetic particles. At BU we feel that we have established that these energetic particles are produced there and we are searching for the mechanism that does that.
10 10
SLIDE 3
Cusp Energy Density comparison published by Chang et al., 1998 June 20, 1996
SLIDE 4
8/27/96
Total Pressure (x10) Magnetic Pressure Plasma Prep. Pressure
SLIDE 5
8/27/96 9/18/96 4/20/99 4/24/99
SLIDE 6
8/27/96 Btotal Vx MICS He++ MICS O+6 MICS H+ Hydra ions
SLIDE 7
Btotal P prep (electrons) P prep (ions) Ion Density (Hydra) Ion Density (Tide) EFI Density
8/27/96
SLIDE 8
Btotal Vx (km/s) MICS He++ MICS O+6 MICS H+ Hydra ions
9/18/96
SLIDE 9
Btotal P prep (electrons) P prep (ions) Ion Density (Hydra) Ion Density (Tide) EFI Density
SLIDE 10
Btotal Vx (km/s) MICS He++ MICS O+6 MICS H+ Hydra ions 4/20/99
SLIDE 11
Btotal P prep (electrons) P prep (ions) Ion Density (Hydra) Ion Density (Tide) EFI Density
SLIDE 12
Btotal Vx (km/s) MICS He++ MICS O+6 MICS H+ Hydra ions
4/24/99
SLIDE 13
Btotal P prep (electrons) P prep (ions) Ion Density (Hydra) Ion Density (Tide) EFI Density
SLIDE 14
Ions Electrons 9/18/96
R=-0.86 R=-0.87 R=-0.93 R=-0.95
SLIDE 15
Ions Electons
8/27/99
R=-0.90 R=-0.95 R=-0.83 R=-0.91
SLIDE 16
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SLIDE 18
SLIDE 19
SLIDE 20
SLIDE 21
Conclusions:
We have attempted to understand the components that must provide the energy density within the high-altitude cusp. With the advertised data from the Polar team there is a deficiency of the measured plasma pressure in creating a balance. The local plasma from the solar wind creates the diamagnetic cavity. The perpendicular pressure provided by both the ions and electrons are highly anti-correlated with the turbulence as expected but the electrons surprisingly show a higher level of anti-correlation. The sense of the polarization of the observed electric component of the turbulence in the direction perpendicular to B can provide resonate acceleration of ions rapidly to high energies.
