Modeling the dawn/dusk asymmetry of field line resonances

Andrew N. Wright; Tom Elsden; Kazue Takahashi

doi:10.1029/2018JA025638

Modeling the dawn/dusk asymmetry of field line resonances

Andrew N. Wright, Tom Elsden, Kazue Takahashi

Applied Mathematics

Research output: Contribution to journal › Article › peer-review

Abstract

Field line resonances (FLRs) are observed to occur preferentially, and have larger amplitudes, at dawn compared to dusk. We present simulations of FLR excitation in a magnetospheric waveguide that can reproduce this behavior. Crucially, our equilibrium is asymmetric about noon. Even when this system is driven in a symmetric fashion about noon, the fast waves that are established in the magnetosphere develop asymmetries – as do the FLRs they excite. Fast mode ray trajectories are employed to show that the asymmetry evolves due to refraction. Preferential FLR excitation at dawn is further reinforced by calculating the Resonance Map. This shows that the Resonant Zone at dawn coincides with a large-amplitude coherent fast mode driver, which is not the case at dusk. These factors result in FLRs having a larger amplitude at dawn compared to dusk.

Original language	English
Pages (from-to)	6443-6456
Number of pages	14
Journal	Journal of Geophysical Research: Space Physics
Volume	123
Issue number	8
Early online date	17 Aug 2018
DOIs	https://doi.org/10.1029/2018JA025638
Publication status	Published - Aug 2018

Keywords

Field line resonances
Pc5 ULF waves
3-D Alfvén resonances
Magnetospheric waveguide

Access to Document

10.1029/2018JA025638

Wright_2018_JGRSP_FLR_FinalPubVersion
©2018. American Geophysical Union. All Rights Reserved. This work is made available online in accordance with the publisher’s policies. This is the final published version of the work, which was originally published at: https://doi.org/10.1029/2018JA025638
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Synthesis of Real and Virtual Space: Syhthesis of real and virtual Space Weather data
Wright, A. N. (PI)
The Leverhulme Trust
1/05/16 → 30/04/19
Project: Standard
Solar and Magnetospheric - Consolidated: Solar and Magnetospheric Magnetohydrodynamics and Plasmas: Theory and Application
Hood, A. W. (PI), Archontis, V. (CoI), De Moortel, I. (CoI), Mackay, D. H. (CoI), Neukirch, T. (CoI), Parnell, C. E. (CoI) & Wright, A. N. (CoI)
Science & Technology Facilities Council
1/04/16 → 31/03/19
Project: Standard

Andrew Nicholas Wright
- anwst-andrews.acuk
- Applied Mathematics - Reader
Person: Academic

Modeling the dawn/dusk asymmetry of Field Line Resonances (dataset)
Elsden, T. W. (Creator), Figshare, 23 Jun 2018
https://doi.org/10.6084/m9.figshare.6662939.v1 and 4 more links, https://doi.org/10.6084/m9.figshare.6662936.v2, https://doi.org/10.6084/m9.figshare.6662933.v1, https://doi.org/10.6084/m9.figshare.6662930.v1, https://doi.org/10.6084/m9.figshare.6662927.v1 (show fewer)
Dataset

Cite this

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title = "Modeling the dawn/dusk asymmetry of field line resonances",

abstract = "Field line resonances (FLRs) are observed to occur preferentially, and have larger amplitudes, at dawn compared to dusk. We present simulations of FLR excitation in a magnetospheric waveguide that can reproduce this behavior. Crucially, our equilibrium is asymmetric about noon. Even when this system is driven in a symmetric fashion about noon, the fast waves that are established in the magnetosphere develop asymmetries – as do the FLRs they excite. Fast mode ray trajectories are employed to show that the asymmetry evolves due to refraction. Preferential FLR excitation at dawn is further reinforced by calculating the Resonance Map. This shows that the Resonant Zone at dawn coincides with a large-amplitude coherent fast mode driver, which is not the case at dusk. These factors result in FLRs having a larger amplitude at dawn compared to dusk.",

keywords = "Field line resonances, Pc5 ULF waves, 3-D Alfv{\'e}n resonances, Magnetospheric waveguide",

author = "Wright, {Andrew N.} and Tom Elsden and Kazue Takahashi",

note = "ANW was partially funded by STFC (ST/N000609/1) and the Leverhulme Trust (RPG-2016-071). TE was funded by the Leverhulme Trust (RPG-2016-071). KT was supported by NASA grant NNX17AD34G.",

year = "2018",

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doi = "10.1029/2018JA025638",

language = "English",

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pages = "6443--6456",

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AU - Wright, Andrew N.

AU - Elsden, Tom

AU - Takahashi, Kazue

N1 - ANW was partially funded by STFC (ST/N000609/1) and the Leverhulme Trust (RPG-2016-071). TE was funded by the Leverhulme Trust (RPG-2016-071). KT was supported by NASA grant NNX17AD34G.

PY - 2018/8

Y1 - 2018/8

N2 - Field line resonances (FLRs) are observed to occur preferentially, and have larger amplitudes, at dawn compared to dusk. We present simulations of FLR excitation in a magnetospheric waveguide that can reproduce this behavior. Crucially, our equilibrium is asymmetric about noon. Even when this system is driven in a symmetric fashion about noon, the fast waves that are established in the magnetosphere develop asymmetries – as do the FLRs they excite. Fast mode ray trajectories are employed to show that the asymmetry evolves due to refraction. Preferential FLR excitation at dawn is further reinforced by calculating the Resonance Map. This shows that the Resonant Zone at dawn coincides with a large-amplitude coherent fast mode driver, which is not the case at dusk. These factors result in FLRs having a larger amplitude at dawn compared to dusk.

AB - Field line resonances (FLRs) are observed to occur preferentially, and have larger amplitudes, at dawn compared to dusk. We present simulations of FLR excitation in a magnetospheric waveguide that can reproduce this behavior. Crucially, our equilibrium is asymmetric about noon. Even when this system is driven in a symmetric fashion about noon, the fast waves that are established in the magnetosphere develop asymmetries – as do the FLRs they excite. Fast mode ray trajectories are employed to show that the asymmetry evolves due to refraction. Preferential FLR excitation at dawn is further reinforced by calculating the Resonance Map. This shows that the Resonant Zone at dawn coincides with a large-amplitude coherent fast mode driver, which is not the case at dusk. These factors result in FLRs having a larger amplitude at dawn compared to dusk.

KW - Field line resonances

KW - Pc5 ULF waves

KW - 3-D Alfvén resonances

KW - Magnetospheric waveguide

U2 - 10.1029/2018JA025638

DO - 10.1029/2018JA025638

M3 - Article

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VL - 123

SP - 6443

EP - 6456

JO - Journal of Geophysical Research: Space Physics

JF - Journal of Geophysical Research: Space Physics

IS - 8

ER -

Modeling the dawn/dusk asymmetry of field line resonances

Abstract

Keywords

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Projects

Synthesis of Real and Virtual Space: Syhthesis of real and virtual Space Weather data

Solar and Magnetospheric - Consolidated: Solar and Magnetospheric Magnetohydrodynamics and Plasmas: Theory and Application

Profiles

Andrew Nicholas Wright

Datasets

Modeling the dawn/dusk asymmetry of Field Line Resonances (dataset)

Cite this