Magnetic conjugacy of Pc1 waves and isolated proton precipitation at subauroral latitudes: Importance of ionosphere as intensity modulation region

Ozaki, M.; Shiokawa, K.; Horne, R.B. ORCID: https://orcid.org/0000-0002-0412-6407; Engebretson, M.K.; Lessard, M.; Ogawa, Y.; Hosokawa, K.; Nose, M.; Ebihara, Y.; Kadokura, A.; Yagitani, S.; Miyoshi, Y.; Hashimoto, S.; Sinha, S.; Sinha, A.K.; Seemala, G.K.; Jun, C.-W.. 2021 Magnetic conjugacy of Pc1 waves and isolated proton precipitation at subauroral latitudes: Importance of ionosphere as intensity modulation region. Geophysical Research Letters, 48 (5), e2020GL091384. https://doi.org/10.1029/2020GL091384

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Official URL: https://agupubs.onlinelibrary.wiley.com/doi/10.102...

Abstract/Summary

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.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	https://doi.org/10.1029/2020GL091384
ISSN:	0094-8276
Additional Keywords:	EMIC waves, Geomagnetic conjugacy, Isolated proton aurora, Pc1 geomagnetic pulsations, Wave‐particle interactions
Date made live:	26 Jan 2021 11:06 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/529487

Item Type:

Publication - Article

Digital Object Identifier (DOI):

https://doi.org/10.1029/2020GL091384

ISSN:

0094-8276

Additional Keywords:

EMIC waves, Geomagnetic conjugacy, Isolated proton aurora, Pc1 geomagnetic pulsations, Wave‐particle interactions

Date made live:

26 Jan 2021 11:06 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/529487