High-latitude magnetospheres: Earth, Jupiter, and Saturn

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A RAS Specialist Discussion Meeting organised by *Licia Ray (Lancaster); Jonathan Nichols (Leicester); Sarah Badman (Lancaster)*Contact: licia.ray@lancaster.ac.uk Energy and momentum are transferred between a planetary atmosphere and its surrounding plasma environment through the high-latitude magnetosphere. In this region, which is characterised by a strong magnetic field and low plasma density, magnetospheric particles are accelerated as they descend down towards the planetary atmosphere, where they can generate intense auroral emissions. Single spacecraft (e.g. FAST) and constellation missions (e.g. Cluster) have extensively explored Earth's high-latitude magnetosphere over the past two decades. The host of ground- and space-based support, along with in situ measurements, numerical models, and theoretical descriptions have helped to build a global picture of the underlying drivers and physical processes that contribute to spatial and temporal variations in these high-latitude regions, although outstanding questions such as the nature of the particle acceleration remain. In contrast, Juno and Cassini Grand Finale missions are currently investigating the high-latitude magnetospheric regions of Jupiter and Saturn, respectively, with unprecedented detail, providing ground-breaking in-situ data. Both missions are complemented by Earth-based remote observations, numerical and theoretical models. This specialist discussion meeting will compare in situ measurements, remote observations, theoretical descriptions, and numerical models of the high-latitude regions of Earth, Jupiter, and Saturn, offering insight into how differing magnetospheric properties i.e. magnetic field strength, plasma sources, rotation rates, solar-wind interaction, influence the properties of the high-latitude magnetosphere and affect the universal processes of auroral acceleration, magnetosphere-ionosphere coupling. Participation is encouraged from the terrestrial and planetary communities with an eye towards increased collaboration. 10:00 Coffee / Registration MORNING SESSION (10:30 - 12:00) – CHAIR LICIA RAY10:30 Bob Ergun (CU-Boulder / LASP)
Physical processes of the aurora at Jupiter and Earth: Similarities and differences (invited)11:00 Jonathan Nichols (Univ. of Leicester)
Response of Jupiter's auroras to conditions in the interplanetary medium as measured by the Hubble Space Telescope and Juno11:15 Rosie Johnson (Univ. of Leicester)
Jupiter's polar ionospheric flows: high resolution mapping of spectral intensity and line-of-sight velocity of H3+ ions11:30 Becky Gray (Lancaster Univ.)
Comparison of UV and X-Ray auroral flares11:45 Rob Fear (Univ. Southampton)
How much flux does a flux transfer event transfer?12:00 LUNCH & POSTERSAFTERNOON SESSION (13:00 - 14:30) – CHAIR SARAH BADMAN13:00 Emma Bunce (Univ. of Leicester)
MI coupling and aurora at Saturn (and Jupiter) (invited)13:30 Colin Forsyth (UCL/MSSL)
When are FACs not facts: Testing single spacecraft assumptions with Swarm13:45 Julia Stawarz (Imperial College)
Field-aligned Poynting flux in Earth's magnetotail14:00 Ewen Davies (Imperial College)
Swept forward magnetic field variability in high latitude regions of Saturn's magnetosphere14:15 Emma Woodfield (British Antarctic Survey) Wave-Particle interactions with energetic electrons at Earth, Jupiter and Saturn14:30 - 15:30 POSTERS & DISCUSSION – CHAIR JONATHAN NICHOLSPatrick Guio (UCL)
Charged particle dynamics in a magnetodisc field structureWill Dunn (UCL/MSSL)
The Auroral Dynamic Duo: Jupiter's independently pulsating X-ray hot spotsJoe Kinrade (Lancaster Univ.)
Rotational modulation of Saturn's UV auroras in 2014Andrew Fazakerley (UCL/MSSL)
Cluster dual-spacecraft observations of Kinetic Alfven Waves in the Plasma Sheet Boundary LayerJohn Coxon (Univ. Southampton)
Energy accumulation, storage and release in the Earth's magnetotail lobes across the substorm cycleArianna Sorba (UCL)
Modelling the compressibility of Saturn's magnetosphere in response to internal and external influencesJoe Reed (Univ. Southampton)
Low Frequency Extensions of the Saturn Kilometric Radiation as a proxy for magnetospheric dynamicsGreg Hunt (Imperial College)
Saturn's field-aligned currents: The roles of plasma angular velocity and effective Pedersen conductivity