Deformation of Ionospheric Potential Pattern by Ionospheric Hall Polarization

Aoi Nakamizo, Akimasa Yoshikawa

研究成果: ジャーナルへの寄稿記事

抄録

The present study shows that the ionospheric Hall polarization can deform the high-latitude ionospheric convection field, which is widely considered to be a manifestation of the convection field in the magnetosphere. We perform the Hall polarization field separation with a potential solver by changing the conductance distribution step by step from a uniform one to a more realistic one. We adopt dawn-dusk and north-south symmetric distributions of conductance and region 1 (R1) field-aligned current (FAC). The pair of the primary field of the R1 system and each gradient of off-diagonal component of conductance tensor (Hall conductance) generates the Hall polarization field and consequently causes potential deformations as follows. (a) The equatorward gradient causes clockwise rotation. (b) The gradient across the terminator, together with the effect of the equatorward gradient, causes the dawn-dusk asymmetry. (c) The high conductance band in the auroral region causes kink-type deformations. In particular, a nested structure at the equatorward edge of the band in the midnight sector well resembles the Harang Reversal. Result (a) can explain the clockwise bias inexplicable by the IMF-By effect alone, the combination of (a) and (b) can explain the clearness and unclearness in the round or crescent shapes of the dawn-dusk cells depending on the IMF-By polarity, and (c) suggests that the ionosphere may not need the upward-FAC for the formation of the Harang Reversal. We suggest that the final structure of the ionospheric potential is established by the combined effects of the magnetospheric requirements (external causes) and ionospheric polarization (internal effect).

元の言語英語
ページ(範囲)7553-7580
ページ数28
ジャーナルJournal of Geophysical Research: Space Physics
124
発行部数9
DOI
出版物ステータス出版済み - 9 1 2019

Fingerprint

ionospherics
polarization
Polarization
causes
IMF
gradients
field aligned currents
convection
Magnetosphere
Ionosphere
magnetosphere
Tensors
ionosphere
asymmetry
magnetospheres
polar regions
ionospheres
polarity
sectors
effect

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Forestry
  • Oceanography
  • Aquatic Science
  • Ecology
  • Water Science and Technology
  • Soil Science
  • Geochemistry and Petrology
  • Earth-Surface Processes
  • Atmospheric Science
  • Earth and Planetary Sciences (miscellaneous)
  • Space and Planetary Science
  • Palaeontology

これを引用

Deformation of Ionospheric Potential Pattern by Ionospheric Hall Polarization. / Nakamizo, Aoi; Yoshikawa, Akimasa.

:: Journal of Geophysical Research: Space Physics, 巻 124, 番号 9, 01.09.2019, p. 7553-7580.

研究成果: ジャーナルへの寄稿記事

@article{ed79a58165f64d8581488654cad619ac,
title = "Deformation of Ionospheric Potential Pattern by Ionospheric Hall Polarization",
abstract = "The present study shows that the ionospheric Hall polarization can deform the high-latitude ionospheric convection field, which is widely considered to be a manifestation of the convection field in the magnetosphere. We perform the Hall polarization field separation with a potential solver by changing the conductance distribution step by step from a uniform one to a more realistic one. We adopt dawn-dusk and north-south symmetric distributions of conductance and region 1 (R1) field-aligned current (FAC). The pair of the primary field of the R1 system and each gradient of off-diagonal component of conductance tensor (Hall conductance) generates the Hall polarization field and consequently causes potential deformations as follows. (a) The equatorward gradient causes clockwise rotation. (b) The gradient across the terminator, together with the effect of the equatorward gradient, causes the dawn-dusk asymmetry. (c) The high conductance band in the auroral region causes kink-type deformations. In particular, a nested structure at the equatorward edge of the band in the midnight sector well resembles the Harang Reversal. Result (a) can explain the clockwise bias inexplicable by the IMF-By effect alone, the combination of (a) and (b) can explain the clearness and unclearness in the round or crescent shapes of the dawn-dusk cells depending on the IMF-By polarity, and (c) suggests that the ionosphere may not need the upward-FAC for the formation of the Harang Reversal. We suggest that the final structure of the ionospheric potential is established by the combined effects of the magnetospheric requirements (external causes) and ionospheric polarization (internal effect).",
author = "Aoi Nakamizo and Akimasa Yoshikawa",
year = "2019",
month = "9",
day = "1",
doi = "10.1029/2018JA026013",
language = "English",
volume = "124",
pages = "7553--7580",
journal = "Journal of Geophysical Research",
issn = "0148-0227",
number = "9",

}

TY - JOUR

T1 - Deformation of Ionospheric Potential Pattern by Ionospheric Hall Polarization

AU - Nakamizo, Aoi

AU - Yoshikawa, Akimasa

PY - 2019/9/1

Y1 - 2019/9/1

N2 - The present study shows that the ionospheric Hall polarization can deform the high-latitude ionospheric convection field, which is widely considered to be a manifestation of the convection field in the magnetosphere. We perform the Hall polarization field separation with a potential solver by changing the conductance distribution step by step from a uniform one to a more realistic one. We adopt dawn-dusk and north-south symmetric distributions of conductance and region 1 (R1) field-aligned current (FAC). The pair of the primary field of the R1 system and each gradient of off-diagonal component of conductance tensor (Hall conductance) generates the Hall polarization field and consequently causes potential deformations as follows. (a) The equatorward gradient causes clockwise rotation. (b) The gradient across the terminator, together with the effect of the equatorward gradient, causes the dawn-dusk asymmetry. (c) The high conductance band in the auroral region causes kink-type deformations. In particular, a nested structure at the equatorward edge of the band in the midnight sector well resembles the Harang Reversal. Result (a) can explain the clockwise bias inexplicable by the IMF-By effect alone, the combination of (a) and (b) can explain the clearness and unclearness in the round or crescent shapes of the dawn-dusk cells depending on the IMF-By polarity, and (c) suggests that the ionosphere may not need the upward-FAC for the formation of the Harang Reversal. We suggest that the final structure of the ionospheric potential is established by the combined effects of the magnetospheric requirements (external causes) and ionospheric polarization (internal effect).

AB - The present study shows that the ionospheric Hall polarization can deform the high-latitude ionospheric convection field, which is widely considered to be a manifestation of the convection field in the magnetosphere. We perform the Hall polarization field separation with a potential solver by changing the conductance distribution step by step from a uniform one to a more realistic one. We adopt dawn-dusk and north-south symmetric distributions of conductance and region 1 (R1) field-aligned current (FAC). The pair of the primary field of the R1 system and each gradient of off-diagonal component of conductance tensor (Hall conductance) generates the Hall polarization field and consequently causes potential deformations as follows. (a) The equatorward gradient causes clockwise rotation. (b) The gradient across the terminator, together with the effect of the equatorward gradient, causes the dawn-dusk asymmetry. (c) The high conductance band in the auroral region causes kink-type deformations. In particular, a nested structure at the equatorward edge of the band in the midnight sector well resembles the Harang Reversal. Result (a) can explain the clockwise bias inexplicable by the IMF-By effect alone, the combination of (a) and (b) can explain the clearness and unclearness in the round or crescent shapes of the dawn-dusk cells depending on the IMF-By polarity, and (c) suggests that the ionosphere may not need the upward-FAC for the formation of the Harang Reversal. We suggest that the final structure of the ionospheric potential is established by the combined effects of the magnetospheric requirements (external causes) and ionospheric polarization (internal effect).

UR - http://www.scopus.com/inward/record.url?scp=85074100089&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85074100089&partnerID=8YFLogxK

U2 - 10.1029/2018JA026013

DO - 10.1029/2018JA026013

M3 - Article

AN - SCOPUS:85074100089

VL - 124

SP - 7553

EP - 7580

JO - Journal of Geophysical Research

JF - Journal of Geophysical Research

SN - 0148-0227

IS - 9

ER -