Home > Research > Publications & Outputs > The Periodic Flapping and Breathing of Saturn's...

Associated organisational unit

Links

Text available via DOI:

View graph of relations

The Periodic Flapping and Breathing of Saturn's Magnetodisk During Equinox

Research output: Contribution to journalJournal article

Published

Standard

The Periodic Flapping and Breathing of Saturn's Magnetodisk During Equinox. / Sorba, A.M.; Achilleos, N.A.; Guio, P.; Arridge, C.S.; Sergis, N.; Dougherty, M.K.

In: Journal of Geophysical Research: Space Physics, Vol. 123, No. 10, 10.2018, p. 8292-8316.

Research output: Contribution to journalJournal article

Harvard

Sorba, AM, Achilleos, NA, Guio, P, Arridge, CS, Sergis, N & Dougherty, MK 2018, 'The Periodic Flapping and Breathing of Saturn's Magnetodisk During Equinox', Journal of Geophysical Research: Space Physics, vol. 123, no. 10, pp. 8292-8316. https://doi.org/10.1029/2018JA025764

APA

Sorba, A. M., Achilleos, N. A., Guio, P., Arridge, C. S., Sergis, N., & Dougherty, M. K. (2018). The Periodic Flapping and Breathing of Saturn's Magnetodisk During Equinox. Journal of Geophysical Research: Space Physics, 123(10), 8292-8316. https://doi.org/10.1029/2018JA025764

Vancouver

Sorba AM, Achilleos NA, Guio P, Arridge CS, Sergis N, Dougherty MK. The Periodic Flapping and Breathing of Saturn's Magnetodisk During Equinox. Journal of Geophysical Research: Space Physics. 2018 Oct;123(10):8292-8316. https://doi.org/10.1029/2018JA025764

Author

Sorba, A.M. ; Achilleos, N.A. ; Guio, P. ; Arridge, C.S. ; Sergis, N. ; Dougherty, M.K. / The Periodic Flapping and Breathing of Saturn's Magnetodisk During Equinox. In: Journal of Geophysical Research: Space Physics. 2018 ; Vol. 123, No. 10. pp. 8292-8316.

Bibtex

@article{31814ad373b443b1bdc05be2a30ab0ab,
title = "The Periodic Flapping and Breathing of Saturn's Magnetodisk During Equinox",
abstract = "Periodic variations have been observed in many field and particle properties in Saturn's magnetosphere, modulated at a period close to the planetary rotation rate. Magnetic field observations by Cassini's magnetometer instrument suggest that in the outer magnetosphere (beyond ∼12 Saturn radii) Saturn's current sheet is periodically displaced with respect to the rotational equator, to a first approximation acting as a rotating, tilted disk. This manifests as a “flapping” mode when observed by the spacecraft. Recent studies suggest the magnetosphere also has a “breathing” mode, expanding and contracting with a period close to the planetary rotation rate. We model these two modes in tandem by combining a global, geometrical model of a tilted and rippled current sheet with a local, force-balance model of Saturn's magnetodisk, accounting for the magnetospheric size and hot plasma content. We simulate the breathing behavior by introducing an azimuthal dependence of the system size. We fit Cassini magnetometer data acquired on equatorial orbits from 23 October to 17 December 2009 (Revs 120–122), close to Saturn equinox, in order that seasonal effects on the current sheet are minimized. We find that our model characterizes well the amplitude and phase of the oscillations in the data, for those passes that show clear periodic signatures in the field. In particular, the Bθ (meridional) component can only be characterized when the breathing mode is included. This study introduces calculations for an oscillating boundary, which provide a basis for understanding the complex relationship between current sheet dynamics and the periodic field perturbations. {\textcopyright}2018. The Authors.",
keywords = "current sheet, magnetosphere, periodic, plasma sheet, Saturn",
author = "A.M. Sorba and N.A. Achilleos and P. Guio and C.S. Arridge and N. Sergis and M.K. Dougherty",
year = "2018",
month = oct,
doi = "10.1029/2018JA025764",
language = "English",
volume = "123",
pages = "8292--8316",
journal = "Journal of Geophysical Research: Space Physics",
issn = "2169-9402",
publisher = "Blackwell Publishing Ltd",
number = "10",

}

RIS

TY - JOUR

T1 - The Periodic Flapping and Breathing of Saturn's Magnetodisk During Equinox

AU - Sorba, A.M.

AU - Achilleos, N.A.

AU - Guio, P.

AU - Arridge, C.S.

AU - Sergis, N.

AU - Dougherty, M.K.

PY - 2018/10

Y1 - 2018/10

N2 - Periodic variations have been observed in many field and particle properties in Saturn's magnetosphere, modulated at a period close to the planetary rotation rate. Magnetic field observations by Cassini's magnetometer instrument suggest that in the outer magnetosphere (beyond ∼12 Saturn radii) Saturn's current sheet is periodically displaced with respect to the rotational equator, to a first approximation acting as a rotating, tilted disk. This manifests as a “flapping” mode when observed by the spacecraft. Recent studies suggest the magnetosphere also has a “breathing” mode, expanding and contracting with a period close to the planetary rotation rate. We model these two modes in tandem by combining a global, geometrical model of a tilted and rippled current sheet with a local, force-balance model of Saturn's magnetodisk, accounting for the magnetospheric size and hot plasma content. We simulate the breathing behavior by introducing an azimuthal dependence of the system size. We fit Cassini magnetometer data acquired on equatorial orbits from 23 October to 17 December 2009 (Revs 120–122), close to Saturn equinox, in order that seasonal effects on the current sheet are minimized. We find that our model characterizes well the amplitude and phase of the oscillations in the data, for those passes that show clear periodic signatures in the field. In particular, the Bθ (meridional) component can only be characterized when the breathing mode is included. This study introduces calculations for an oscillating boundary, which provide a basis for understanding the complex relationship between current sheet dynamics and the periodic field perturbations. ©2018. The Authors.

AB - Periodic variations have been observed in many field and particle properties in Saturn's magnetosphere, modulated at a period close to the planetary rotation rate. Magnetic field observations by Cassini's magnetometer instrument suggest that in the outer magnetosphere (beyond ∼12 Saturn radii) Saturn's current sheet is periodically displaced with respect to the rotational equator, to a first approximation acting as a rotating, tilted disk. This manifests as a “flapping” mode when observed by the spacecraft. Recent studies suggest the magnetosphere also has a “breathing” mode, expanding and contracting with a period close to the planetary rotation rate. We model these two modes in tandem by combining a global, geometrical model of a tilted and rippled current sheet with a local, force-balance model of Saturn's magnetodisk, accounting for the magnetospheric size and hot plasma content. We simulate the breathing behavior by introducing an azimuthal dependence of the system size. We fit Cassini magnetometer data acquired on equatorial orbits from 23 October to 17 December 2009 (Revs 120–122), close to Saturn equinox, in order that seasonal effects on the current sheet are minimized. We find that our model characterizes well the amplitude and phase of the oscillations in the data, for those passes that show clear periodic signatures in the field. In particular, the Bθ (meridional) component can only be characterized when the breathing mode is included. This study introduces calculations for an oscillating boundary, which provide a basis for understanding the complex relationship between current sheet dynamics and the periodic field perturbations. ©2018. The Authors.

KW - current sheet

KW - magnetosphere

KW - periodic

KW - plasma sheet

KW - Saturn

U2 - 10.1029/2018JA025764

DO - 10.1029/2018JA025764

M3 - Journal article

VL - 123

SP - 8292

EP - 8316

JO - Journal of Geophysical Research: Space Physics

JF - Journal of Geophysical Research: Space Physics

SN - 2169-9402

IS - 10

ER -