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An isolated, bright cusp aurora at Saturn
Baines, K. H.; Dougherty, M. K.; Gray, R. L. +16 more
Saturn's dayside aurora displays a number of morphological features poleward of the main emission region. We present an unusual morphology captured by the Hubble Space Telescope on 14 June 2014 (day 165), where for 2 h, Saturn's FUV aurora faded almost entirely, with the exception of a distinct emission spot at high latitude. The spot remained fix…
27 August 2001 substorm: Preonset phenomena, two main onsets, field-aligned current systems, and plasma flow channels in the ionosphere and in the magnetosphere
Moiseev, A. V.; Wang, J. Y.; Mishin, V. M. +2 more
We supplement the results of the 27 August 2001 substorm studied earlier in the series of papers. Described is the plasma flow in the nightside ionosphere from the near-polar region from the polar cap to the auroral oval during the substorm preonset phase and two expansion onsets, EO1 and EO2, produced by reconnection in the closed tail (magnetic …
A method to predict magnetopause expansion in radial IMF events by MHD simulations
Å afránková, J.; Němeček, Z.; Sibeck, D. G. +2 more
This paper presents a method for taking into account changes of solar wind parameters in the foreshock using global MHD simulations. We simulate four events with very distant subsolar magnetopause crossings that occurred during quasi-radial interplanetary magnetic field (IMF) intervals lasting from one to several hours. Using previous statistical …
Influence of the Ambient Electric Field on Measurements of the Actively Controlled Spacecraft Potential by MMS
Andriopoulou, M.; Nakamura, R.; Torbert, R. B. +5 more
Space missions with sophisticated plasma instrumentation such as Magnetospheric Multiscale, which employs four satellites to explore near-Earth space benefit from a low electric potential of the spacecraft, to improve the plasma measurements and therefore carry instruments to actively control the potential by means of ion beams. Without control, t…
Diamagnetic depression observations at Saturn's magnetospheric cusp by the Cassini spacecraft
Coates, Andrew J.; Krupp, Norbert; Arridge, Christopher S. +4 more
The magnetospheric cusp is a region where shocked solar wind plasma can enter a planetary magnetosphere, after magnetic reconnection has occurred at the dayside magnetopause or in the lobes. The dense plasma that enters the high-latitude magnetosphere creates diamagnetic effects whereby a depression is observed in the magnetic field. We present ob…
Characteristics of ionospheric flux rope at the terminator observed by Venus Express
Zhang, T. L.; Chen, Y. Q.; Wang, G. Q. +1 more
We investigate the characteristics of the magnetic flux rope in the Venusian ionosphere near the terminator observed by the Venus Express while previous works about flux rope by PVO are mainly in the subsolar region. The probability to observe the flux rope becomes larger as solar activity strengthens. A statistical work during solar maximum prese…
Dawn Auroral Breakup at Saturn Initiated by Auroral Arcs: UVIS/Cassini Beginning of Grand Finale Phase
Badman, S. V.; Bonfond, B.; Gérard, J. -C. +4 more
We present Cassini auroral observations obtained on 11 November 2016 with the Ultraviolet Imaging Spectrograph at the beginning of the F-ring orbits and the Grand Finale phase of the mission. The spacecraft made a close approach to Saturn's southern pole and offered a remarkable view of the dayside and nightside aurora. With this sequence we ident…
Characterization of Jupiter's secondary auroral oval and its response to hot plasma injections
Woodfield, E. E.; Gray, R. L.; Badman, S. V. +1 more
We present Jovian auroral observations from the 2014 January Hubble Space Telescope (HST) campaign and characterize the auroral second oval feature with particular attention to the response to hot plasma injections. The location of the second oval feature lies between the Ganymede and Europa moon footprint contours between 150 and 240° system III …
The role of plasma slowdown in the generation of Rhea's Alfvén wings
Dougherty, Michele K.; Russell, Christopher T.; Fatemi, Shahab +5 more
Alfvén wings are known to form when a conducting or mass-loading object slows down a flowing plasma in its vicinity. Alfvén wings are not expected to be generated when an inert moon such as Rhea interacts with Saturn's magnetosphere, where the plasma impacting the moon is absorbed and the magnetic flux passes unimpeded through the moon. However, i…
Low-frequency oscillatory flow signatures and high-speed flows in the Earth's magnetotail
Nilsson, H.; Hamrin, M.; Norqvist, P. +6 more
Using plasma sheet data from Cluster 1 spacecraft from 2001 till 2011, we statistically investigate oscillatory signatures in the plasma bulk flow. These periodic oscillations are compared to high-speed and quiet flows. Periodic oscillations are observed approximately 8% of the time, while high-speed flows and quiet flows are observed around 0.5% …