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Title: Polar cusp: optical and particle characteristics-dynamics

Photometric observations from two stations on Svalbard, Norway, were used to map the location and dynamics of polar-cusp auroras. Coordinated observations of low-energy electron precipitation from satellite HILAT and optical observations from the ground are discussed. Cases are presented showing the dynamical behavior of cusp auroras and the local magnetic field related to changes in the interplanetary magnetic field (IMF) and irregularities in the solar wind plasma. Dynamical phenomena with different time scales are studied. South and northward expansions of the midday sector of the auroral oval are discussed in relation to IMF variations and geomagnetic substorm activity. Intensifications and rapid poleward motions of discrete auroral structures in the cusp region are shown to be associated with local Pi type magnetic pulsations, each event lasting a few minutes. These small scale dynamical phenomena are discussed in relation to different models of plasma penetration across the dayside magnetopause, from the magnetosheath to the polar cusp region of the magnetosphere.
Authors:
; ; ; ;
Publication Date:
OSTI Identifier:
5215553
Report Number(s):
AD-A-170382/6/XAB; AFGL-TR-86-0151
Resource Type:
Technical Report
Research Org:
Air Force Geophysics Lab., Hanscom AFB, MA (USA)
Country of Publication:
United States
Language:
English
Subject:
71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSICS; AURORAE; DYNAMICS; EARTH MAGNETOSPHERE; SOLAR WIND; POLAR CUSP; INTERACTIONS; ELECTRON PRECIPITATION; INTERPLANETARY MAGNETIC FIELDS; MAGNETIC STORMS; MAGNETOPAUSE; POLAR REGIONS; CHARGED-PARTICLE PRECIPITATION; EARTH ATMOSPHERE; MAGNETIC FIELDS; MECHANICS; SOLAR ACTIVITY 640201* -- Atmospheric Physics-- Auroral, Ionospheric, & Magetospheric Phenomena; 640203 -- Atmospheric Physics-- Magnetospheric Phenomena-- (-1987)