'The Nature of Reconfiguration In Giant Planet Magnetospheres'
Lead Research Organisation:
University College London
Department Name: Physics and Astronomy
Abstract
Variability, or 'reconfiguration', in the size and global plasma content of the magnetospheres of the planets Saturn and Jupiter may be driven by different physical processes. In this project, we aim to focus mainly on three of these through a combination of theoretical modelling and observation:
(1) The solar wind driver: We aim to model the response of the gas giant magnetospheres to changes in solar wind dynamic pressure, capturing an effective 'compressibility' for these systems. We will also investigate how this compressibility is affected by changes in plasma pressure within these magnetospheres.
(2) The internal driver, periodic: We will aim to model some of the Cassini spacecraft observations near / at Saturn equinox, in order to further investigate the periodic dynamics imposed on the outer magnetospheric disc by the planet's 'rotating anomaly / camshaft signal'.
(3) The internal driver, secular: Jupiter's auroral oval displays occasional few-degree shifts in location, which apparently are due to dramatic internal magnetospheric reconfigurations. We aim to perform a more extensive characterisation and investigation of the contribution made to these episodes by two principal mechanisms: (i) Variations in volcanic activity of Jupiter's moon, Io; (ii) Variations in internal plasma pressure of Jupiter's magnetosphere.
(1) The solar wind driver: We aim to model the response of the gas giant magnetospheres to changes in solar wind dynamic pressure, capturing an effective 'compressibility' for these systems. We will also investigate how this compressibility is affected by changes in plasma pressure within these magnetospheres.
(2) The internal driver, periodic: We will aim to model some of the Cassini spacecraft observations near / at Saturn equinox, in order to further investigate the periodic dynamics imposed on the outer magnetospheric disc by the planet's 'rotating anomaly / camshaft signal'.
(3) The internal driver, secular: Jupiter's auroral oval displays occasional few-degree shifts in location, which apparently are due to dramatic internal magnetospheric reconfigurations. We aim to perform a more extensive characterisation and investigation of the contribution made to these episodes by two principal mechanisms: (i) Variations in volcanic activity of Jupiter's moon, Io; (ii) Variations in internal plasma pressure of Jupiter's magnetosphere.
Organisations
Publications
Sorba A
(2018)
The Periodic Flapping and Breathing of Saturn's Magnetodisk During Equinox
in Journal of Geophysical Research: Space Physics
Studentship Projects
| Project Reference | Relationship | Related To | Start | End | Student Name |
|---|---|---|---|---|---|
| ST/N50449X/1 | 30/09/2015 | 30/03/2021 | |||
| 1698479 | Studentship | ST/N50449X/1 | 30/09/2015 | 31/12/2018 | Arianna Sorba |
| Description | 1. A 2-D force balance magnetodisc model was used to investigate the compressibility of Saturn's magnetosphere. We found that the magnetosphere is more compressible in low solar wind conditions, due to formation of disk-like magnetic field structure, and that the magnetosphere is also more compressible when hot plasma content is greater, due to change in magnetosphere morphology. 2. Saturn's equatorial current sheet displays periodic dynamical behaviour at roughly 10.7 hours. We modelled the magnetic field with a geometric current sheet model and force-balance magnetodisc model. We found that including both displacement and thickness modulation of current sheet improves agreement with data. |
| Exploitation Route | These findings are now published in peer-reviewed journal articles, and so can be taken forward by interested members of the scientific community. |
| Sectors | Other |