Search Publications
The "Alfvénic surge" at substorm onset/expansion and the formation of "Inverted Vs": Cluster and IMAGE observations
Frey, H. U.; Goldstein, M. L.; Mozer, F. S. +4 more
From multipoint, in situ observations and imaging, we reveal the injection-powered, Alfvénic nature of auroral acceleration during onset and expansion of a substorm. It is shown how Alfvénic variations over time dissipate to form large-scale, inverted-V structures characteristic of quasistatic aurora. This characterization is made possible through…
Pulsations of the polar cusp aurora at Saturn
Krupp, N.; Roussos, E.; Mitchell, D. G. +4 more
The magnetospheric cusp is a region connecting the interplanetary environment to the ionosphere and enabling solar wind particles to reach the ionosphere. We report the detection of several isolated high-latitude auroral emissions with the Ultraviolet Imaging Spectrograph of the Cassini spacecraft. We suggest that these auroral spots, located in t…
Variation of Jupiter's aurora observed by Hisaki/EXCEED: 1. Observed characteristics of the auroral electron energies compared with observations performed using HST/STIS
Tsuchiya, Fuminori; André, Nicolas; Fujimoto, Masaki +9 more
Temporal variation of Jupiter's northern aurora is detected using the Extreme Ultraviolet Spectroscope for Exospheric Dynamics (EXCEED) on board JAXA's Earth-orbiting planetary space telescope Hisaki. The wavelength coverage of EXCEED includes the H2 Lyman and Werner bands at 80-148 nm from the entire northern polar region. The prominen…
Modeling the magnetospheric X-ray emission from solar wind charge exchange with verification from XMM-Newton observations
Palmroth, Minna; Milan, Steve E.; Carter, Jennifer A. +3 more
An MHD-based model of terrestrial solar wind charge exchange (SWCX) is created and compared to 19 case study observations in the 0.5-0.7 keV emission band taken from the European Photon Imaging Cameras on board XMM-Newton. This model incorporates the Global Unified Magnetosphere-Ionosphere Coupling Simulation-4 MHD code and produces an X-ray emiss…
Cassini plasma observations of Saturn's magnetospheric cusp
Coates, Andrew J.; Krupp, Norbert; Arridge, Christopher S. +6 more
The magnetospheric cusp is a funnel-shaped region where shocked solar wind plasma is able to enter the high-latitude magnetosphere via the process of magnetic reconnection. The plasma observations include various cusp signatures such as ion energy dispersions and diamagnetic effects. We present an overview analysis of cusp plasma observations at t…
Challenges associated with near-Earth nightside current
Liemohn, Michael W.; Welling, Daniel T.; Ilie, Raluca +1 more
Every magnetic field of solar and planetary space environments is associated with a current of differentially flowing charged particles. Electric potential patterns in geospace and near other planets are also closely linked with currents. Close to the Earth, particularly in the near-Earth nightside magnetosphere, several current systems wax and wa…
Polytropic index of magnetosheath ions based on homogeneous MHD Bernoulli Integral
Ma, Yuduan; Cao, Jinbin; Pang, Xuexia
This paper uses Cluster data during the period from 2001 to 2010 to study the polytropic processes of magnetosheath ions. Utilizing the method of homogeneous magnetohydrodynamic (MHD) Bernoulli integral (MBI), we first identify streamflow tubes, then use the constant of polytropic relation to guarantee that the streamflow tube experiences an uncha…
Cassini observations of ionospheric plasma in Saturn's magnetotail lobes
Coates, A. J.; Dougherty, M. K.; Reisenfeld, D. B. +8 more
Studies of Saturn's magnetosphere with the Cassini mission have established the importance of Enceladus as the dominant mass source for Saturn's magnetosphere. It is well known that the ionosphere is an important mass source at Earth during periods of intense geomagnetic activity, but lesser attention has been dedicated to study the ionospheric ma…
Is the flow-aligned component of IMF really able to impact the magnetic field structure of Venusian magnetotail?
Barabash, S.; Futaana, Y.; Wei, Y. +5 more
An earlier statistical survey suggested that the flow-aligned component of upstream interplanetary magnetic field (IMF) may play an important role in controlling the lobe asymmetries of the Venusian magnetotail. The tail current sheet would be displaced and the magnetic field configuration would show asymmetries with respect to the current sheet. …
Plasma observations during the Mars atmospheric "plume" event of March-April 2012
Gurnett, D. A.; Barabash, S.; Holmström, M. +10 more
We present initial analyses and conclusions from plasma observations made during the reported "Mars plume event" of March-April 2012. During this period, multiple independent amateur observers detected a localized, high-altitude "plume" over the Martian dawn terminator, the cause of which remains to be explained. The estimated brightness of the pl…