Polar observations of the characteristics of the dayside high - PowerPoint PPT Presentation

Polar PI conference call December 3, 2004 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

The Chapman Ferraro Cusp Observationally Polar has shown that the cusp is a large region and is the site of continuous large fluxes of energetic 10 particles. 10 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.

Cusp Energy Density comparison published by Chang et al., 1998 June 20, 1996

Total Pressure (x10) Magnetic Pressure 8/27/96 Plasma Prep. Pressure

9/18/96 4/24/99 8/27/96 4/20/99

8/27/96 B total Vx MICS He ++ MICS O +6 MICS H + Hydra ions

B total 8/27/96 P prep (electrons) P prep (ions) Ion Density (Hydra) Ion Density (Tide) EFI Density

B total V x (km/s) 9/18/96 MICS He++ MICS O+6 MICS H+ Hydra ions

Btotal P prep (electrons) P prep (ions) Ion Density (Hydra) Ion Density (Tide) EFI Density

4/20/99 B total V x (km/s) MICS He ++ MICS O +6 MICS H + Hydra ions

B total P prep (electrons) P prep (ions) Ion Density (Hydra) Ion Density (Tide) EFI Density

B total V x (km/s) 4/24/99 MICS He ++ MICS O +6 MICS H + Hydra ions

B total P prep (electrons) P prep (ions) Ion Density (Hydra) Ion Density (Tide) EFI Density

Ions Electrons R=-0.87 R=-0.86 9/18/96 R=-0.95 R=-0.93

Ions Electons R=-0.95 R=-0.90 8/27/99 R=-0.83 R=-0.91

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.