Magnetic Conjugacy of Pc1 Waves and Isolated Proton Precipitation at Subauroral Latitudes: Importance of Ionosphere as Intensity Modulation Region

Authors

Mitsunori Ozaki, Kanazawa University
Kazuo Shiokawa, Nagoya University
Richard B. Horne, British Antarctic Survey
Mark J. Engebretson, Augsburg UniversityFollow
Marc Lessard, University of New Hampshire Durham
Yasunobu Ogawa, National Institute of Polar Research
Keisuke Hosokawa, The University of Electro-Communications
Masahito Nosé, Nagoya University
Yusuke Ebihara, Research Institute for Sustainable Humanosphere
Akira Kadokura, National Institute of Polar Research
Satoshi Yagitani, Kanazawa University
Yoshizumi Miyoshi, Nagoya University
Shion Hashimoto, Kanazawa University
Shipra Sinha, Indian Institute of Geomagnetism
Ashwini K. Sinha, Indian Institute of Geomagnetism
Gopi K. Seemala, Indian Institute of Geomagnetism
Chae Woo Jun, Nagoya University

ORCID

0000-0002-3882-8108

Document Type

Letter to the Editor

Publication Date

3-16-2021

DOI

10.1029/2020GL091384

Abstract

Pc1 geomagnetic pulsations, equivalent to electromagnetic ion cyclotron waves in the magnetosphere, display a specific amplitude modulation, though the region of the modulation remains an open issue. To classify whether the amplitude modulation has a magnetospheric or ionospheric origin, an isolated proton aurora (IPA), which is a proxy of Pc1 wave-particle interactions, is compared with the associated Pc1 waves for a geomagnetic conjugate pair, Halley Research Base in Antarctica and Nain in Canada. The temporal variation of an IPA shows a higher correlation coefficient (0.88) with Pc1 waves in the same hemisphere than that in the opposite hemisphere. This conjugate observation reveals that the classic cyclotron resonance is insufficient to determine the amplitude modulation. We suggest that direct wave radiation from the ionospheric current by IPA should also contribute to the amplitude modulation.

Comments

Published in Geophysical Research Letters at https://doi.org/10.1029/2020GL091384 under a Creative Commons Attribution-NonCommercial-NoDerivatives license

Recommended Citation

Ozaki, Mitsunori; Shiokawa, Kazuo; Horne, Richard B.; Engebretson, Mark J.; Lessard, Marc; Ogawa, Yasunobu; Hosokawa, Keisuke; Nosé, Masahito; Ebihara, Yusuke; Kadokura, Akira; Yagitani, Satoshi; Miyoshi, Yoshizumi; Hashimoto, Shion; Sinha, Shipra; Sinha, Ashwini K.; Seemala, Gopi K.; and Jun, Chae Woo, "Magnetic Conjugacy of Pc1 Waves and Isolated Proton Precipitation at Subauroral Latitudes: Importance of Ionosphere as Intensity Modulation Region" (2021). Faculty Authored Articles. 65.
https://idun.augsburg.edu/faculty_scholarship/65