skip to main content

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

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 convectingmore » 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.« less
Authors:
; ; ; ; ;
Publication Date:
OSTI Identifier:
5961345
Resource Type:
Journal Article
Resource Relation:
Journal Name: J. Geophys. Res.; (United States); Journal Volume: 91:A3
Research Org:
Space Science Laboratory, NASA Marshall Space Flight Center, Huntsville, Alabama
Country of Publication:
United States
Language:
English
Subject:
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