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Title: Polar rain: solar coronal electrons in the Earth's magnetosphere

Technical Report ·
OSTI ID:5822958

Low-energy-electron measurements collected by ISEE 1 reveal the frequent presence of field-aligned fluxes of few-hundred-eV electrons in the geomagnetic tail lobes. In the northern tail lobe these electrons are most prominent when the interplanetary magnetic field is directed away from the Sun. This characteristic helps identify the electrons as polar rain electrons. By mapping the tail lobe velocity distribution function into the solar wind, previous suggestions that the polar rain is indeed of solar wind origin and is due to the access of electrons to the magnetotail lobe were confirmed. It was demonstrated that the more energetic component of the polar rain is composed of electrons from the solar wind strahl - a field-aligned component of the solar wind which is difficult to measure but which is thought to be caused by the collisionless transit of hundred-eV electrons from the inner solar corona to 1 AU.

Research Organization:
National Aeronautics and Space Administration, Greenbelt, MD (USA). Goddard Space Flight Center
OSTI ID:
5822958
Report Number(s):
N-85-16726; NASA-TM-86150
Country of Publication:
United States
Language:
English