The source of the electric field in the nightside magnetosphere

Technical Report · Sun Jun 01 04:00:00 EDT 1975

OSTI ID:7338032

Stern, D P

In the open magnetosphere model magnetic field lines from the polar caps connect to the interplanetary magnetic field and conduct an electric field from interplanetary space to the polar ionosphere. By examining the magnetic flux involved it is concluded that only slightly more than half of the magnetic flux in the polar caps belongs to open field lines and that such field lines enter or leave the magnetosphere through narrow elongated windows stretching the tail. These window regions are identified with the tail's boundary region and shift their position with changes in the interplanetary magnetic field, in particular when a change of interplanetary magnetic sector occurs. The circuit providing electric current in the magnetopause and the plasma sheet is extended across those windows; thus energy is drained from the interplanetary electric field and an electric potential drop is produced across the plasma sheet. The polar cap receives its electric field from interplanetary space on the day side from open magnetic field lines and on the night side from closed field lines leading to the plasma sheet. The theory described provides improved understanding of magnetic flux bookkeeping, of the origin of Birkeland currents, and of the boundary layer of the geomagnetic tail. (Author) (GRA)

• Research Organization: National Aeronautics and Space Administration, Greenbelt, Md. (USA). Goddard Space Flight Center
• OSTI ID: 7338032
• Report Number(s): N-75-28596; NASA-TM-X-70837; X-602-75-17
• Country of Publication: United States
• Language: English

Related Subjects

640203* -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
EARTH ATMOSPHERE
ELECTRIC FIELDS
INTERPLANETARY SPACE
IONOSPHERE
MAGNETIC FIELDS
MAGNETIC FLUX
MAGNETOSPHERE
PLASMA SHEET
SPACE