The increase in OH rotational temperature during an active aurora event
OH rotational temperatures have been observed at the Syowa Station, Antarctica (69° S, 39° E), which is located in the middle of the auroral zone and has a high-sensitivity spectrometer for the spectral region of the OH 8-4 band. A dataset of 153 nights was acquired during the 200...
| Main Authors: | , , , |
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| Format: | Article |
| Language: | English |
| Published: |
Copernicus Publications
2010-03-01
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| Series: | Annales Geophysicae |
| Online Access: | https://www.ann-geophys.net/28/705/2010/angeo-28-705-2010.pdf |
| Summary: | OH rotational temperatures have been observed at the Syowa Station,
Antarctica (69° S, 39° E), which is located in the middle of the
auroral zone and has a high-sensitivity spectrometer for the spectral region
of the OH 8-4 band. A dataset of 153 nights was acquired during the 2008
austral winter season. Of the 153 nights, the weather and aurora conditions
were only suitable on 6 nights to study the relationship between auroral
activity and OH airglow variation. Of these 6 nights, a significant increase
in the rotational temperature and a decrease in the intensity related to an
aurora activity were identified on the night of 27/28 March 2008, but no
such variations were seen during the other nights. The horizontal magnetic
field disturbance on the night of 27/28 March was the largest of that
winter, while the cosmic radio noise absorption was also very strong. These
facts indicate that, compared with the other nights, a large flux of
high-energy auroral particles precipitated during the night. It is suggested
that the observed variations in the OH rotational temperature and airglow
intensity were caused by a lowering of the average airglow height as a
result of OH depletion in the upper part of the layer where high-energy
auroral particles can reach. |
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| ISSN: | 0992-7689 1432-0576 |