Physics
Scientific paper
Nov 1989
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=1989jgr....9415335w&link_type=abstract
Journal of Geophysical Research (ISSN 0148-0227), vol. 94, Nov. 1, 1989, p. 15335-15348. Research supported by USAF and Boston U
Physics
34
Atmospheric Composition, Electron Energy, Magnetosphere-Ionosphere Coupling, Photoelectrons, Solar Activity Effects, Solar X-Rays, Atmospheric Ionization, Electron Sources
Scientific paper
Data from low altitude plasma instrument (LAPI) on Dynamics Explorer 2 document a population of high-energy (up to 800 eV) atmospheric photoelectrons that has not been reported in the published literature. The source of these photoelectrons is postulated to be the soft X-ray portion of the whole sun spectrum. This conclusion is supported by sunrise-sunset characteristics that track those of the classical (below 60 eV) EUV-produced photoelectrons, and theoretical results from two models that incorporate the soft X-ray portion of the solar spectrum. The models include K-shell ionization effects and predict peaks in the photoelectron spectrum due to Auger electrons emitted from oxygen and nitrogen. The peak for nitrogen is observed as predicted, but the peak for oxygen is barely observable. Excellent quantitative agreement is achieved between theory and experiment by using reasonable adjustments to the few published soft X-ray spectra based on solar activity. The upflowing energetic photoelectrons provide a heretofore unknown source of electrons to the magnetosphere. They occur whenever and wherever the sun is up, that is, at all invariant latitudes. Their density is low, but they are steady and ubiquitous. If scattering and trapping occur on closed field lines, then photoelectrons could contribute as a significant particle source and thus represent a new facet of magnetosphere-ionosphere coupling.
David Winningham J.
Decker Dwight T.
Jasperse John R.
Kozyra Janet U.
Nagy Andrew F.
No associations
LandOfFree
Energetic (above 60 eV) atmospheric photoelectrons does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Energetic (above 60 eV) atmospheric photoelectrons, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Energetic (above 60 eV) atmospheric photoelectrons will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1616799