University of Oulu

Partamies, N., Whiter, D., Kadokura, A., Kauristie, K., Nesse Tyssøy, H., Massetti, S., Stauning, P., and Raita, T. (2017), Occurrence and average behavior of pulsating aurora, J. Geophys. Res. Space Physics, 122, 5606– 5618, doi:10.1002/2017JA024039

Occurrence and average behavior of pulsating aurora

Saved in:
Author: Partamies, N.1,2; Whiter, D.3; Kadokura, A.4;
Organizations: 1Department of Arctic Geophysics, University Centre in Svalbard, Longyearbyen, Norway
2Birkeland Centre for Space Science, Bergen, Norway
3Department of Physics and Astronomy, University of Southampton, Southampton, UK
4Space and Upper Atmospheric Sciences Group, National Institute of Polar Research, Tokyo, Japan
5Arctic Research, Finnish Meteorological Institute, Helsinki, Finland
6Department of Physics and Technology, University of Bergen, Bergen, Norway
7INAF-IAPS, Institute for Space Astrophysics and Planetology, Rome, Italy
8Danish Meteorological Institute, Copenhagen, Denmark
9Sodankylä Geophysical Observatory, University of Oulu, Oulu, Finland
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 3.5 MB)
Persistent link: http://urn.fi/urn:nbn:fi-fe2019092429533
Language: English
Published: American Geophysical Union, 2017
Publish Date: 2019-09-24
Description:

Abstract

Motivated by recent event studies and modeling efforts on pulsating aurora, which conclude that the precipitation energy during these events is high enough to cause significant chemical changes in the mesosphere, this study looks for the bulk behavior of auroral pulsations. Based on about 400 pulsating aurora events, we outline the typical duration, geomagnetic conditions, and change in the peak emission height for the events. We show that the auroral peak emission height for both green and blue emission decreases by about 8 km at the start of the pulsating aurora interval. This brings the hardest 10% of the electrons down to about 90 km altitude. The median duration of pulsating aurora is about 1.4 h. This value is a conservative estimate since in many cases the end of event is limited by the end of auroral imaging for the night or the aurora drifting out of the camera field of view. The longest durations of auroral pulsations are observed during events which start within the substorm recovery phases. As a result, the geomagnetic indices are not able to describe pulsating aurora. Simultaneous Antarctic auroral images were found for 10 pulsating aurora events. In eight cases auroral pulsations were seen in the southern hemispheric data as well, suggesting an equatorial precipitation source and a frequent interhemispheric occurrence. The long lifetimes of pulsating aurora, their interhemispheric occurrence, and the relatively high‐precipitation energies make this type of aurora an effective energy deposition process which is easy to identify from the ground‐based image data.

see all

Series: Journal of geophysical research. Space physics
ISSN: 2169-9380
ISSN-E: 2169-9402
ISSN-L: 2169-9380
Volume: 122
Issue: 5
Pages: 5606 - 5618
DOI: 10.1002/2017JA024039
OADOI: https://oadoi.org/10.1002/2017JA024039
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
Subjects:
Funding: This work was partly supported by the Research Council of Norway under CoE contract 223252. The Italian ASC in NAL is funded by PNRA.
Copyright information: © 2017. American Geophysical Union. All Rights Reserved.