Evidence of high densities and ion outflows in the polar cap during the recovery phase

Journal Article · Sat Mar 01 00:00:00 EST 1986 · J. Geophys. Res.; (United States)

DOI:https://doi.org/10.1029/JA091iA03p03321· OSTI ID:5961345

Gallagher, D L; Menietti, J D; Burch, J L; Persoon, A M; Waite, Jr, J H; Chappell, C R

During the recovery phase of a large storm on October 14, 1981, instruments on board Dynamics Explorer 1 (DE 1) the Retarding Ion Mass Spectrometer (RIMS), the High Altitude Plasma Instrument (HAPI), and the Plasma Wave Instrument (PWI) detected unusually high plasma densities and ion flows in the polar cap. At the time of detection, DE 1 was located at a radial distance of about 3.5 earth radii, a magnetic local time near midnight, and between 70/sup 0/ and 80/sup 0/ invariant latitude. Total plasma density was found to be about 50 cm/sup -3/, an order of magnitude above median polar cap densities at the altitude of observation. In addition, highly collimated flows of hydrogen and oxygen are found flowing through a background hydrogen plasma. The O/sup +/ component of the plasma discussed is not directly identified but is inferred to be O/sup +/ through the combined analysis of data from three instruments. Results of the combined instrument analysis indicate that the detected plasma was composed of outflowing H/sup +/ with a density of 6-10 cm/sup -3/ with a temperature of about 0.15 eV; isotropic H/sup +/ with a density of about 15-20 cm/sup -3/; and outflowing and strongly convecting O/sup +/ with an average density of about 20 cm/sup -3/ and a temperature of about 0.26 eV. The flux of outflowing H/sup +/ and O/sup +/ are both about 10/sup 7/ cm/sup -2/ s/sup -1/. The data indicate that the O/sup +/ detected by HAPI seems to originate in the dayside ionosphere, while the H/sup +/ detected by RIMS has a source in the nightside polar cap.

• Research Organization: Space Science Laboratory, NASA Marshall Space Flight Center, Huntsville, Alabama
• OSTI ID: 5961345
• Journal Information: J. Geophys. Res.; (United States), Vol. 91:A3
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
IONOSPHERE
ION DRIFT
PLASMA DENSITY
DAILY VARIATIONS
EXPLORER SATELLITES
HYDROGEN IONS
ION TEMPERATURE
MAGNETIC STORMS
OXYGEN IONS
POLAR REGIONS
CHARGED PARTICLES
EARTH ATMOSPHERE
IONS
PLANETARY IONOSPHERES
SATELLITES
VARIATIONS
640201* - Atmospheric Physics- Auroral
Ionospheric
& Magetospheric Phenomena