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6300‚àövñ (OI) airglow at higher midlatitudes during solar maximum
thesisposted on 2023-05-27, 18:19 authored by Nichol, DG
This thesis describes work carried out at Hobart (42.9¬¨‚àûS, 147.3¬¨‚àûE) during the 1968 - 1970 solar/auroral maximum on the airglow emissions of atomic oxygen particularly the red 6300‚àövñ line. (This 'line' is actually a doublet : see chapter two). Both the red and the green 5577‚àövñ lines originate from forbidden transitions of OI; these are the (3P - ¬¨œÄD) and the (¬¨œÄD - ¬¨œÄS) transitions respectively. Until recently the green line was much more studied than the 6300‚àövñ line, partly because it is usually stronger in the normal night airglow and also because photo-electron detectors are more sensitive in its spectral range. It is really only during the last fifteen years or so that adequately red sensitive detectors have become available to study the weak night airglow. Thus although these OI lines have been known to exist in auroras for over a century (Angstrom 1868, Zollner 1870) the recent solar maximum is only the second available for detailed study of the weak red night emissions. The previous maximum of 1957 - 1959 proved very fruitful for airglow/auroral studies so it was hoped that the recent maximum would be the same. However this maximum was considerably weaker and few opportunities were available to study such novel aurbral features as the 'mantel aurora' (Sandford 1964) or the Stable Auroral Red Arc (SAR-arc) (Barbier 1959), Cole 1965a) both originally detected during Lilo previous maximum. Furthermore the normal night airglow appeared to be less intense by a factor of five during the 1968 -1970 maximum than during the previous one. This is rather puzzling and would not be expected in terms of the solar flux or ionospheric content differences. Possible explanations are examined in various chapters of this thesis.
Rights statementCopyright 1970 the author - The University is continuing to endeavour to trace the copyright owner(s) and in the meantime this item has been reproduced here in good faith. We would be pleased to hear from the copyright owner(s). The following articles by the author, included in PDF have been removed for copyright reasons: Excitation of 6300‚àövñ (OI) airglow by soft electron fluxes; A summer-time midnight enchantment of 6300‚àövñ airglow; The pre-dawn enchantment of ˜í¬™6300‚àövñ airglow at higher midlatitudes. Thesis (Ph.D.) - University of Tasmania, 1971. Includes bibliography.