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Direct Measurement of Low-Energy Electron Foreshock Beams
DOI: 10.1029/2019JA026470 Bibcode: 2019JGRA..124.2380S

Soucek, Jan; Píša, David; Santolík, Ondrej

Electrostatic plasma waves above and below the local electron plasma frequency represent a characteristic feature of the foreshock region. These waves are known to be generated by electron beams originating from the bow shock and their spectrum varies from narrowband intense waves close to foreshock edge to weaker broadband emissions further downs…

2019 Journal of Geophysical Research (Space Physics)
Cluster 6
Machine Learning Analysis of Jupiter's Far-Ultraviolet Auroral Morphology
DOI: 10.1029/2019JA027120 Bibcode: 2019JGRA..124.8884N

Milan, S. E.; Nichols, J. D.; Kamran, A.

We present the first principal component analysis of Jupiter's far-ultraviolet auroras, in order to identify the most repeatable sources of variation in the auroral morphology. We show that the most recurrent source of variance is emission just poleward of the statistical oval on the dawnside. Further significant repeatable sources of variance are…

2019 Journal of Geophysical Research (Space Physics)
eHST 6
Solar Wind Dynamic Pressure Upstream From Saturn: Estimation From Magnetosheath Properties and Comparison With SKR
DOI: 10.1029/2019JA026819 Bibcode: 2019JGRA..124.7799T

Thomsen, M. F.; Jackman, C. M.; Lamy, L.

An analytical method is developed by which measurements made by the Cassini spacecraft in Saturn's magnetosheath can be used to infer the upstream solar wind parameters, specifically the solar wind speed (Vsw) and the dynamic pressure (Pd). The method is validated by comparing the results with other estimates of these parameters, includ…

2019 Journal of Geophysical Research (Space Physics)
Cassini 6
Variability of Precipitating Ion Fluxes During the September 2017 Event at Mars
DOI: 10.1029/2018JA026123 Bibcode: 2019JGRA..124..420M

Holmström, M.; Leblanc, F.; Luhmann, J. +15 more

In this work, we study the influence of the September 2017 solar event on the precipitating heavy ion fluxes toward Mars' atmosphere as seen by Mars Atmosphere and Volatile EvolutioN/Solar Wind Ion Analyzer, an energy and angular ion spectrometer and by Mars Atmosphere and Volatile EvolutioN/Suprathermal and Thermal Ion Composition instrument, an …

2019 Journal of Geophysical Research (Space Physics)
MEx 6
Survey of Saturn Whistler Mode Hiss Intensity
DOI: 10.1029/2019JA026656 Bibcode: 2019JGRA..124.4266M

Kurth, W. S.; Averkamp, T. F.; Menietti, J. D.

We have conducted an extensive survey of whistler mode hiss emission at Saturn using nearly the complete data set from the Cassini Radio and Plasma Wave Science investigation. We distinguish the hiss emission by frequency and intensity threshold criteria. The survey includes all longitudes and latitudes >25° for r < 10 RS, limited…

2019 Journal of Geophysical Research (Space Physics)
Cassini 5
Currents Associated With Saturn's Intra-D Ring Azimuthal Field Perturbations
DOI: 10.1029/2019JA026588 Bibcode: 2019JGRA..124.5675H

Dougherty, M. K.; Cowley, S. W. H.; Bunce, E. J. +4 more

During the final 22 full revolutions of the Cassini mission in 2017, the spacecraft passed at periapsis near the noon meridian through the gap between the inner edge of Saturn's D ring and the denser layers of the planet's atmosphere, revealing the presence of an unanticipated low-latitude current system via the associated azimuthal perturbation f…

2019 Journal of Geophysical Research (Space Physics)
Cassini 5
Heavy Ion Flows in the Upper Ionosphere of the Venusian North Pole
DOI: 10.1029/2018JA026271 Bibcode: 2019JGRA..124.4597P

Fedorov, A.; Barabash, S.; Futaana, Y. +5 more

We investigate the heavy ion density and velocity in the Venusian upper ionosphere near the North Pole, using the Ion Mass Analyzer, a part of the Analyzer of Space Plasmas and Energetic Atoms 4, together with the magnetic field instruments on Venus Express. The measurements were made during June-July 2014, covering the aerobraking campaign with l…

2019 Journal of Geophysical Research (Space Physics)
VenusExpress 5
Current Density in Saturn's Equatorial Current Sheet: Cassini Magnetometer Observations
DOI: 10.1029/2018JA025970 Bibcode: 2019JGRA..124..279M

Arridge, C. S.; Martin, C. J.

The equatorial current sheet at Saturn is the result of a rapidly rotating magnetosphere. The sheet itself exhibits periodic seasonal and diurnal movements as well as aperiodic movements of a currently unknown origin, along with periodic thickening and thinning of the magnetodisc, and azimuthal changes in the thickness due to local effects in the …

2019 Journal of Geophysical Research (Space Physics)
Cassini 5
Multispacecraft Study of the Interaction Between an Interplanetary Shock and a Solar Wind Flux Rope
DOI: 10.1029/2019JA026748 Bibcode: 2019JGRA..124.9760B

Burgess, D.; Blanco-Cano, X.; Kajdič, P. +1 more

Interplanetary (IP) shocks are driven in the heliosphere by fast coronal ejecta, they can accelerate particles and are associated with solar energetic particle and energetic storm particle events. IP shocks can interact with structures in the solar wind and with magnetospheres. We show how the properties of an IP shock change when it interacts wit…

2019 Journal of Geophysical Research (Space Physics)
Cluster 5
Kelvin-Helmholtz Waves Magnetic Curvature and Vorticity: Four-Spacecraft Cluster Observations
DOI: 10.1029/2019JA026484 Bibcode: 2019JGRA..124.3347K

Kieokaew, Rungployphan; Foullon, Claire

[1] Magnetopause Kelvin-Helmholtz (KH) waves are rich in complex magnetic and flow structures which are key to understand the role of these waves in facilitating the solar wind plasma transport into the Earth's magnetosphere. Four spacecraft in tetrahedral configuration provide the tools necessary for characterizing in situ magnetic geometry and v…

2019 Journal of Geophysical Research (Space Physics)
Cluster 5