Simultaneous relativistic-electron and auroral-particle access to the polar caps during interplanetary magnetic field Bz northward: A scenario for an open-field line source of auroral particles

Technical Report · Fri Dec 01 00:00:00 EST 1989

OSTI ID:6862795

Gussenhoven, M S; Mullen, E G

The large magnetic storm of February 1986 provides a unique opportunity to assess whether existing open-closed theories of the magnetosphere can consistently account for precipitating particle signatures measured at 840 km under a wide variety of solar wind and solar particle conditions. The simultaneous observation are prepared for relativistic electrons associated with a solar proton event and of auroral ions and electrons associated with a polar cap arc event, made across the central polar cap using detectors on board the Defense Meteorological Satellite Program (DMSP) satellites. On February 7 while a solar proton event was still in progress, polar cap arc activity (interplanetary magnetic field (IMF)B2 large and positive, Kp = 3+) occurred prior to a prolonged period of oval arc activity (IMF B2 large and negative, Kp = 6-). Throughout these periods the following are identified: the equatorward edge of the relativistic electron precipitation; the outer zone electron poleward and equatorward boundaries; the equatorward auroral electron and ion boundaries; and the auroral electron transition boundary. The history of the boundaries is presented as the transition from intense polar cap activity to intense auroral oval activity takes place. The data clearly show that the polar cap region of relativistic electron precipitation does not change significantly as the sign of B2 changes. On the other hand, the boundary layer population, which contains auroral arcs and 1- to 10-keV ion precipitation, expands to fill most of the polar cap for B2 northward and greatly contracts as B2 turns southward. The expansion is not symmetric between poles.

• Research Organization: Air Force Geophysics Lab., Hanscom AFB, MA (USA)
• OSTI ID: 6862795
• Report Number(s): AD-A-222580/3/XAB; GL-TR-90-0139
• Resource Relation: Other Information: Pub. in Jnl. of Geophysical Research, Vol. 94, No. A12, 17121-17132(1 Dec 1989)
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
AURORAE
CHARGED-PARTICLE PRECIPITATION
ELECTRON PRECIPITATION
AURORAL OVAL
BOUNDARY LAYERS
EARTH MAGNETOSPHERE
ELECTRONS
ENERGY-LEVEL TRANSITIONS
INTERPLANETARY MAGNETIC FIELDS
IONS
MAGNETIC STORMS
POLAR REGIONS
POLAR-CAP ABSORPTION
RELATIVISTIC RANGE
SATELLITES
SOLAR RADIATION
SOLAR WIND
ABSORPTION
CHARGED PARTICLES
EARTH ATMOSPHERE
ELEMENTARY PARTICLES
ENERGY RANGE
FERMIONS
LAYERS
LEPTONS
MAGNETIC FIELDS
RADIATIONS
SOLAR ACTIVITY
STELLAR RADIATION
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena