Search Publications
Variation in the Pedersen Conductance Near Jupiter's Main Emission Aurora: Comparison of Hubble Space Telescope and Galileo Measurements
Nichols, J. D.; Vogt, M. F.; Rutala, M. J. +1 more
We present the first large-scale statistical survey of the Jovian main emission (ME) to map auroral properties from their ionospheric locations out into the equatorial plane of the magnetosphere, where they are compared directly to in-situ spacecraft measurements. We use magnetosphere-ionosphere (MI) coupling theory to calculate currents from the …
Parallel Electron Beams at Io: Numerical Simulations of the Dense Plasma Wake
Bagenal, F.; Dols, V.; Paterson, W. R.
In 1995, the Galileo spacecraft traversed the wake of Io at ∼900 km altitude. The instruments onboard detected intense bi-directional field-aligned electron beams (∼140 eV-150 keV), embedded in a dense, cold and slow plasma wake (Nel ∼ 35,000 cm−3, Ti < 10 eV, V < 3 km/s). Similar electron beams were also det…
The Structure of the Warped Io Plasma Torus Constrained by the Io Footprint
Saur, Joachim; Schlegel, Stephan
Standard models of force balance along Jovian field lines predict the location of the Io Plasma Torus to be the centrifugal equator of Jupiter's magnetosphere, that is, the position along the magnetic field lines farthest away from Jupiter's rotational axis. In many models, the centrifugal equator is assumed to lay on a plane, calculated from a (s…
Identifying the Variety of Jovian X-Ray Auroral Structures: Tying the Morphology of X-Ray Emissions to Associated Magnetospheric Dynamics
Jackman, C. M.; Kurth, W. S.; Branduardi-Raymont, G. +12 more
We define the spatial clustering of X-rays within Jupiter's northern auroral regions by classifying their distributions into "X-ray auroral structures." Using data from Chandra during Juno's main mission observations (24 May 2016 to 8 September 2019), we define five X-ray structures based on their ionospheric location and calculate the distributio…
On the Relation Between Auroral Morphologies and Compression Conditions of Jupiter's Magnetopause: Observations From Juno and the Hubble Space Telescope
Hospodarsky, G. B.; Kurth, W. S.; Bonfond, B. +11 more
Jupiter displays the most powerful auroral emissions in our solar system, which result from strong energy dissipation in Jupiter's surrounding space environment. Although mass and energy in Jupiter's magnetosphere mostly come from the innermost Galilean moon Io's volcanic activity and Jupiter's rotation, solar wind perturbations can play crucial r…
Jovian Auroral Electron Precipitation Budget—A Statistical Analysis of Diffuse, Mono-Energetic, and Broadband Auroral Electron Distributions
Saur, J.; Mauk, B. H.; Salveter, A. +1 more
Recent observations by the Juno spacecraft have shown that electrons contributing to Jupiter's main auroral emission appear to be frequently characterized by broadband electron distributions, but also less often mono-energetic electron distributions are observed as well. In this work, we quantitatively derive the occurrence rates of the various el…
Relation of Jupiter's Dawnside Main Emission Intensity to Magnetospheric Currents During the Juno Mission
Nichols, J. D.; Cowley, S. W. H.
We compare Jupiter's dawn-side main auroral emission intensity observed by the Hubble Space Telescope with the simultaneous magnitude of the dawn-side magnetospheric equatorial radial current as observed by Juno during Orbits 3-7. We show that the peak auroral intensity and the square of the radial current per radian of azimuth are strongly correl…
Determining the Beaming of Io Decametric Emissions: A Remote Diagnostic to Probe the Io-Jupiter Interaction
Kurth, W. S.; Cecconi, B.; Lamy, L. +8 more
We investigate the beaming of 11 Io-Jupiter decametric (Io-DAM) emissions observed by Juno/Waves, the Nançay Decameter Array, and NenuFAR. Using an up-to-date magnetic field model and three methods to position the active Io Flux Tube (IFT), we accurately locate the radiosources and determine their emission angle θ from the local magnetic field vec…
Constraining Europa's Subsolar Atmosphere With a Joint Analysis of HST Spectral Images and Galileo Magnetic Field Data
Saur, J.; Cervantes, S.
We constrain Europa's tenuous atmosphere on the subsolar hemisphere by combining two sets of observations: oxygen emissions at 1,304 and 1,356 Å from Hubble Space Telescope (HST) spectral images and Galileo magnetic field measurements from its closest encounter, the E12 flyby. We describe Europa's atmosphere with three neutral gas species: global …
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…