Articles | Volume 28, issue 3
https://doi.org/10.5194/angeo-28-705-2010
https://doi.org/10.5194/angeo-28-705-2010
ANGEO Communicates
 | 
05 Mar 2010
ANGEO Communicates |  | 05 Mar 2010

The increase in OH rotational temperature during an active aurora event

H. Suzuki, M. Tsutsumi, T. Nakamura, and M. Taguchi

Abstract. 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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