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High resolution electron energy spectra in an active aurora at the onset of the magnetic storm of March 26, 1976
Author(s) -
Edmonson D. A.,
Peterson W. K.,
Doering J. P.,
Feldman P. D.
Publication year - 1977
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/gl004i002p00075
Subject(s) - spectral line , physics , rocket (weapon) , pitch angle , electron , altitude (triangle) , maxima , attenuation , electron precipitation , intensity (physics) , isotropy , storm , computational physics , atmospheric sciences , atomic physics , magnetosphere , geophysics , meteorology , optics , nuclear physics , astronomy , plasma , geometry , art , mathematics , performance art , engineering , art history , aerospace engineering
The spectrum of high energy precipitating auroral electrons (2‐26 keV) was measured at altitudes from 97‐175 km at the onset of the magnetic storm of 26 March 1976 by a rocket borne experiment launched from Ft. Churchill, Manitoba. The spectra show an unusual double‐peaked distribution, with maxima at 4.5 and 17 keV, that persists for the full four minutes of data acquisition. Multiple structure within the main peaks is also noted. The energies and intensities of the two peaks observed at 163 km and 0° pitch angle vary independently during a sudden brightening on the downleg of the rocket flight. Thirty spectra taken during a slow roll maneuver near apogee show that the pitch angle distribution for the two peaks in the energy spectrum is isotropic over both the precipitating and backscattered hemispheres. Spectra taken near the end of the flight show energy dependent attenuation with altitude but fluctuations in auroral intensity preclude a detailed analysis.