Observation of O+ (P-4-D-4(0)) lines in electron aurora over Svalbard
2004 (English)In: Annales Geophysicae, ISSN 0992-7689, E-ISSN 1432-0576, Vol. 22, no 8, 2805-2817 p.Article in journal (Refereed) Published
This work reports on observations of O+ lines in aurora over Svalbard, Norway. The Spectrographic Imaging Facility measures auroral spectra in three wavelength intervals(H-beta, N-2(+) 1N(0,2) and N-2(+) 1N(1,3)). The oxygen ion P-4-D-4(0) multiplet (4639-4696 Angstrom) is blended with the N-2(+) 1N(1,3) band. It is found that in electron aurora, the brightness of this multiplet, is on average, about 0.1 of the N-2(+) 1N(0,2) total brightness. A joint optical and incoherent scatter radar study of an electron aurora event shows that the ratio is enhanced when the ionisation in the upper E-layer (140-190 km) is significant with respect to the E-layer peak below 130 km. Rayed arcs were observed on one such occasion, whereas on other occasions the auroral intensity was below the threshold of the imager. A one-dimensional electron transport model is used to estimate the cross section for production of the multiplet in electron collisions, yielding 0.18 x 10(-18) cm(2).
Place, publisher, year, edition, pages
2004. Vol. 22, no 8, 2805-2817 p.
meteorology and atmospheric dynamics, airglow and aurora, ionosphere, particle precipitation, field-aligned currents, optical aurora, spectra, oxygen, radar, impact, excitation, emissions, scatter, n2
IdentifiersURN: urn:nbn:se:kth:diva-23808ISI: 000224483900015ScopusID: 2-s2.0-4143141474OAI: oai:DiVA.org:kth-23808DiVA: diva2:342507
QC 20100525 QC 201111012010-08-102010-08-102014-12-15Bibliographically approved