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Title: Magnetospheric structure and dynamics: A multisatellite approach

This report reviews progress during the first year of a contract to study magnetospheric structure and dynamics. Four areas of scientific investigation are highlighted. Pressure gradients form in the geotail because ions drift preferentially toward the dusk flank. These pressure gradients drive field aligned currents that close in the ionosphere and which provide a natural explanation of the Harang discontinuity when the full electrodynamics are modelled. Observations made during a passage by DE 2 through the dayside cusp at a time when the IMF was directed northwards are consistent with magnetic merging occurring on field line that map to the poleward cusp boundary. The authors infer that tail lobe field lines were merging with magnetosheath field lines at the magnetopause tailward of the external cusp. During the March 1989 magnetic storm, the DMSP F9 spacecraft observed extensive substantial decreases in equatorial ion density in the post-dusk sector. Modelling calculations show that the depletions were caused by unusually large upward flows moving the equatorial F region peak above 850 km. Calculations of ion cyclotron wave group velocities show that they are sensitive to both the hot and cold plasma populations. Calculated group delays agree with their earlier observations.
Authors:
Publication Date:
OSTI Identifier:
5256635
Report Number(s):
AD-A-237674/7/XAB
CNN: F19628-90-K-0003
Resource Type:
Technical Report
Research Org:
Boston Univ., MA (United States). Center for Space Physics
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; EARTH MAGNETOSPHERE; DYNAMICS; MORPHOLOGY; ELECTRODYNAMICS; EQUATOR; F REGION; HARANG DISCONTINUITY; HIGH TEMPERATURE; ION DENSITY; ION DRIFT; IONOSPHERE; MAGNETIC RECONNECTION; MAGNETIC STORMS; MAGNETOTAIL; POLAR CUSP; PRESSURE GRADIENTS; SATELLITES; AURORAL OVAL; EARTH ATMOSPHERE; MECHANICS; PLANETARY IONOSPHERES 640201* -- Atmospheric Physics-- Auroral, Ionospheric, & Magetospheric Phenomena