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Use of Twenty Years CLUSTER/FGM Data to Observe the Mean Behavior of the Magnetic Field and Current Density of Earth's Magnetosphere
Dunlop, M. W.; Robert, P.
The data from the CLUSTER FGM magnetometer, recorded for 20 years at ESA's Cluster Science Archive, as well as the position of the spacecraft, have been used to form a database aligned in time. It allows the calculation of curl(B) over all the lifetime of the mission (representing the current density via µ0J⃗=curl⃗>(B⃗>). The B⃗…
Variability of Jupiter's Main Auroral Emission and Satellite Footprints Observed With HST During the Galileo Era
Clarke, John T.; Moore, Luke; Bonfond, Bertrand +3 more
Hubble Space Telescope images of Jupiter's UV aurora show that the main emission occasionally contracts or expands, shifting toward or away from the magnetic pole by several degrees in response to changes in the solar wind dynamic pressure and Io's volcanic activity. When the auroral footprints of the Galilean satellites move with the main emissio…
Asymmetric Interaction of a Solar Wind Reconnecting Current Sheet and Its Magnetic Hole With Earth's Bow Shock and Magnetopause
Liemohn, Michael W.; Karlsson, Tomas; Liu, Terry Z. +3 more
We report results of our multi-spacecraft analysis of a solar wind reconnecting current sheet (RCS) and its solar wind magnetic hole (SWMH) observed on November 20, 2018. In the solar wind, the normal vector to the current sheet plane makes an angle of 32° with the Sun-Earth line. A combination of tilted current sheet plane and foreshock effects c…
Ganymede's Auroral Footprint Latitude: Comparison With Magnetodisc Model
Bonfond, B.; Nichols, J. D.; Vogt, M. F. +3 more
Variations of Ganymede's auroral footprint locations are presented based on observations by the Hubble Space Telescope in 2007 and 2016. The poleward and equatorward shifts of Ganymede's footprint could be influenced by the mass outflow rate from Io and the solar wind compression, as the internal and external factors respectively. We compare our r…
Hybrid Simulations of the Cusp and Dayside Magnetosheath Dynamics Under Quasi-Radial Interplanetary Magnetic Fields
Lavraud, B.; Zou, Y.; Chen, L. -J. +2 more
Under quasi-radial interplanetary magnetic fields (IMF), foreshock turbulence can have an impact on the magnetosheath and cusps depending on the location of the quasi-parallel shock. We perform three-dimensional simulations of Earth's dayside magnetosphere using the hybrid code HYPERS, and compare northward and southward quasi-radial IMF configura…
The Influence of Localized Dynamics on Dusk-Dawn Convection in the Earth's Magnetotail
Case, N. A.; Grocott, A.; Lane, J. H.
Previous work has shown that earthward convective flow bursts in the magnetotail have a dusk-dawn (v⊥y) component that is controlled by the historical state of the Interplanetary Magnetic Field (IMF) By component. Here, we analyze 27 years of Cluster, THEMIS and Geotail plasma and magnetic field data and identify 1,639 magnet…
Solar Wind Velocities at Comets C/2011 L4 Pan-STARRS and C/2013 R1 Lovejoy Derived Using a New Image Analysis Technique
Jones, Geraint H.; Ramanjooloo, Yudish
The ion tails of bright comets have long been considered as a natural tracers of the solar wind (SW) near these objects. Studies of comets and their ion tails allow inexpensive monitoring of key SW structures in the inner heliosphere, much of which is otherwise only accessible by in situ SW spacecraft measurements. Here, we present a novel techniq…
Solar Minimum Exospheric Neutral Density Near the Subsolar Magnetopause Estimated From the XMM Soft X-Ray Observations on 12 November 2008
Pagani, C.; Kuntz, K. D.; Koutroumpa, D. +3 more
The Earth's magnetosheath and cusps emit soft X-rays due to the charge exchange between highly charged solar wind ions and exospheric hydrogen atoms. The Lunar Environment Heliospheric X-ray Imager and Solar wind Magnetosphere Ionosphere Link Explorer missions are scheduled to image the Earth's dayside magnetosphere system in soft X-rays to invest…
Observations of the First Harmonic of Saturn Kilometric Radiation During Cassini's Grand Finale
Lamy, Laurent; Fischer, Georg; Kurth, William S. +6 more
Clear first harmonic emissions of Saturn Kilometric Radiation are discovered during the Cassini Grand Finale orbits. Both ordinary (O) and extraordinary (X) mode fundamental emissions accompanied by X mode harmonics are observed. Analysis shows that the frequency ratio between the fundamental and harmonic emissions is 2.01 ± 0.08, and the harmonic…
Illuminating the Motions of Jupiter's Auroral Dawn Storms
Nichols, J. D.; Rutala, M. J.; Clarke, J. T. +1 more
Jupiter's auroral main emission (ME) has long been considered to be the result of currents keeping plasma corotating with the surrounding magnetosphere. As a result, the ME corotates with the planet, and individual auroral features making up the ME roughly follow suit. Jupiter's dawn storms, some of the rarest and brightest auroral features within…