Observation of O + ( 4 P- 4 D 0 ) lines in electron aurora over Svalbard
International audience 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 ? , N + 2 1N(0,2) and N + 2 1N(1,3)). The oxygen ion multiplet (4639-4696Å) is blended with the band. I...
Main Authors: | , , , , , , |
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Other Authors: | , , , , , , , , |
Format: | Article in Journal/Newspaper |
Language: | English |
Published: |
HAL CCSD
2004
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Subjects: | |
Online Access: | https://hal.science/hal-00317574 https://hal.science/hal-00317574/document https://hal.science/hal-00317574/file/angeo-22-2805-2004.pdf |
Summary: | International audience 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 ? , N + 2 1N(0,2) and N + 2 1N(1,3)). The oxygen ion multiplet (4639-4696Å) is blended with the band. It is found that in electron aurora, the brightness of this multiplet, is on average, about 0.1 of the 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 (140-190km) is significant with respect to the E-layer peak below 130km. 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 0.18x10 -18 cm 2 . |
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