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Tomographic reconstruction of 630.0 nm emission structure for a polar cap arc
Author(s) -
Doe Richard A.,
Kelly John D.,
Semeter Joshua L.,
Steele David P.
Publication year - 1997
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/97gl00828
Subject(s) - brightness , arc (geometry) , polar , plasma , geology , optics , physics , atmospheric sciences , geometry , astronomy , mathematics , quantum mechanics
Monochromatic imagers located at two sites in the Canadian Arctic were operated concurrently during the poleward transit of a duskside sun‐aligned polar cap arc on 19 February 1996. The arc was observed by both stations in 630.0 nm images over a 5‐min period. Profiles of 630.0 nm brightness versus elevation angle were extracted from pairs of images along a great circle defined by the two ground stations. These data were then supplied as inputs to a tomographic reconstruction for the arc‐related 630.0 nm volume emission rate in a vertical (latitude vs. altitude) plane: η 630 (lat,z). The time evolution of η 630 (lat,z) structure for this polar cap arc indicates that a modification to the electron source energy distribution and not a thermospheric process (such as neutral heating and plasma diffusion/decay) controlled the arc‐related 630.0 nm emission.