University of Oulu

Fukizawa, M., Sakanoi, T., Tanaka, Y., Ogawa, Y., Hosokawa, K., Gustavsson, B., Kauristie, K., Kozlovsky, A., Raita, T., Brändström, U., and Sergienko, T.: Reconstruction of precipitating electrons and three-dimensional structure of a pulsating auroral patch from monochromatic auroral images obtained from multiple observation points, Ann. Geophys., 40, 475–484, https://doi.org/10.5194/angeo-40-475-2022, 2022.

Reconstruction of precipitating electrons and three-dimensional structure of a pulsating auroral patch from monochromatic auroral images obtained from multiple observation points

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Author: Fukizawa, Mizuki1; Sakanoi, Takeshi2; Tanaka, Yoshimasa1,3,4;
Organizations: 1National Institute of Polar Research, Tachikawa 190-8518, Japan
2Graduate School of Science, Tohoku University, Sendai 980-8578, Japan
3Polar Environment Data Science Center, Joint Support-Center for Data Science Research, Research Organization of Information and Systems, Tachikawa 190-0014, Japan
4Department of Polar Science, The Graduate University for Advanced Studies (SOKENDAI), Tachikawa 190-8518, Japan
5Graduate School of Informatics and Engineering, University of Electro-Communications, Chofu 182-8585, Japan
6Department of Physics and Technology, Arctic University of Norway (UiT), 9037 Tromsø, Norway
7Space Research and Observation Technologies, Finnish Meteorological Institute, 00101 Helsinki, Finland
8Sodankylä Geophysical Observatory, University of Oulu, 90014 Oulu, Finland
9Solar Terrestrial Atmosphere Research Program (STAR), Swedish Institute of Space Physics (IRF), 981 28 Kiruna, Sweden
Format: article
Version: published version
Access: open
Online Access: PDF Full Text (PDF, 4.8 MB)
Persistent link: http://urn.fi/urn:nbn:fi-fe202301306583
Language: English
Published: Copernicus Publications, 2022
Publish Date: 2023-01-30
Description:

Abstract

In recent years, aurora observation networks using high-sensitivity cameras have been developed in the polar regions. These networks allow dimmer auroras, such as pulsating auroras (PsAs), to be observed with a high signal-to-noise ratio. We reconstructed the horizontal distribution of precipitating electrons using computed tomography with monochromatic PsA images obtained from three observation points. The three-dimensional distribution of the volume emission rate (VER) of the PsA was also reconstructed. The characteristic energy of the reconstructed precipitating electron flux ranged from 6 to 23 keV, and the peak altitude of the reconstructed VER ranged from 90 to 104 km. We evaluated the results using a model aurora and compared the model’s electron density with the observed one. The electron density was reconstructed correctly to some extent, even after a decrease in PsA intensity. These results suggest that the horizontal distribution of precipitating electrons associated with PsAs can be effectively reconstructed from ground-based optical observations.

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Series: Annales geophysicae
ISSN: 0992-7689
ISSN-E: 1432-0576
ISSN-L: 0992-7689
Volume: 40
Issue: 4
Pages: 475 - 484
DOI: 10.5194/angeo-40-475-2022
OADOI: https://oadoi.org/10.5194/angeo-40-475-2022
Type of Publication: A1 Journal article – refereed
Field of Science: 115 Astronomy and space science
Subjects:
Funding: The first author is a research fellow (DC) of the Japan Society for the Promotion of Science (JSPS). This work was performed using facilities of the National Institute of Polar Research (NIPR). The study has been supported by JSPS KAKENHI (grant nos. JP17K05672, JP20J11829, and JP21H01152). EISCAT is an international association supported by research organizations in China (CRIRP), Finland (SA), Japan (NIPR), Norway (NFR), Sweden (VR), and the United Kingdom (UKRI). We thank Kellinsalmi Mirjam and Carl-Fredrik Enell for maintaining the MIRACLE camera network and data flow. The database construction for the imager data at Skibotn and the EISCAT radar data has been supported by the IUGONET (Inter-university Upper atmosphere Global Observation NETwork) project (http://www.iugonet.org/, last access: 7 July 2022).
Dataset Reference: The MIRACLE EMCCD camera data from ABK and KIL are available from the University of Oulu and the Finnish Meteorological Institute (2022, https://doi.org/10.23729/e86df44b-8dad-44e5-89f3-4bea0d3d1236, Raita and Kauristie, 2022). The auroral images obtained by four WMI CCD cameras at SKB can be obtained at http://pc115.seg20.nipr.ac.jp/www/optical/watec/skb/awi/rawdata/ (Ogawa, 2022a). The EISCAT data are available at http://pc115.seg20.nipr.ac.jp/www/eiscatdata/ (Ogawa, 2022b).
  https://doi.org/10.23729/e86df44b-8dad-44e5-89f3-4bea0d3d1236
http://pc115.seg20.nipr.ac.jp/www/optical/watec/skb/awi/rawdata/
http://pc115.seg20.nipr.ac.jp/www/eiscatdata/
Copyright information: © Author(s) 2022. This work is distributed under the Creative Commons Attribution 4.0 License.
  https://creativecommons.org/licenses/by/4.0/