Search Publications
The extension of ionospheric holes into the tail of Venus
Fedorov, A.; Barabash, S.; Holmström, M. +8 more
Ionospheric holes are Cytherian nightside phenomena discovered by the NASA Pioneer Venus Orbiter, featuring localized plasma depletions driven by prominent and unexplained enhancements in the draped interplanetary magnetic field. Observed only during solar maximum, the phenomenon remains unexplained, despite their frequent observation during the f…
Solar filament impact on 21 January 2005: Geospace consequences
Escoubet, C. P.; Tsurutani, B. T.; Cattell, C. +21 more
On 21 January 2005, a moderate magnetic storm produced a number of anomalous features, some seen more typically during superstorms. The aim of this study is to establish the differences in the space environment from what we expect (and normally observe) for a storm of this intensity, which make it behave in some ways like a superstorm. The storm w…
The plasma depletion layer in Saturn's magnetosheath
Coates, A. J.; Russell, C. T.; Dougherty, M. K. +5 more
A plasma depletion layer (PDL) of reduced plasma density and enhanced magnetic field strength can form in the magnetosheath (shocked solar wind) adjacent to the magnetopause boundary of a planetary magnetosphere. The dominant factor controlling the level of plasma depletion and field enhancement in Earth's PDL is the magnetic shear across the magn…
On the identification of time interval threshold in the twin-CME scenario
Li, Gang; Ding, Liu-Guan; Jiang, Yong +3 more
Recently it has been suggested that the "twin-CME" scenario may be a very effective mechanism in causing extreme solar energetic particle (SEP) events and, in particular, ground level enhancement (GLE) events. Ding et al. (2013) performed a statistical examination of the twin-CME scenario with a total of 126 fast and wide western coronal mass ejec…
Observation of a retreating x line and magnetic islands poleward of the cusp during northward interplanetary magnetic field conditions
Fuselier, S. A.; Trattner, K. J.; Eriksson, S. +3 more
When the interplanetary magnetic field is northward, reconnection occurs in each hemisphere on lobe field lines, poleward of the cusp. We have identified a case where the Cluster spacecraft crossed the magnetopause and encountered a tailward retreating x line. The x line is identified by the encounter of both a tailward and sunward jet, as well as…
Isothermal magnetosheath electrons due to nonlocal electron cross talk
Schwartz, S. J.; Mitchell, J. J.
Heating of the various plasma species at the Earth's collisionless bow shock is not fully understood. Although the total amount of heating is constrained by the one-fluid Rankine-Hugoniot relations in terms of local plasma conditions, the partition of energy between, e.g., electrons and ions, is influenced by particle kinetics which are not consid…
The magnetic structure of Saturn's magnetosheath
Dougherty, M. K.; Jia, X.; Masters, A. +1 more
A planet's magnetosheath extends from downstream of its bow shock up to the magnetopause, where the solar wind flow is deflected around the magnetosphere and the solar wind-embedded magnetic field lines are draped. This makes the region an important site for plasma turbulence, instabilities, reconnection, and plasma depletion layers. A relatively …
Nighttime sensitivity of ionospheric VLF measurements to X-ray bursts from a remote cosmic source
Giménez de Castro, C. Guillermo; Raulin, Jean-Pierre; Correia, Emilia +2 more
On 22 January 2009, a series of X-ray bursts were emitted by the soft gamma ray repeater SGR J1550-5418. Some of these bursts produced enhanced ionization in the nighttime lower ionosphere. These ionospheric disturbances were studied using X-ray measurements from the Anti-Coincidence Shield of the Spectrometer for Integral onboard the Internationa…
Cassini nightside observations of the oscillatory motion of Saturn's northern auroral oval
Coates, A. J.; Dougherty, M. K.; Kurth, W. S. +8 more
In recent years we have benefitted greatly from the first in-orbit multi-wavelength images of Saturn's polar atmosphere from the Cassini spacecraft. Specifically, images obtained from the Cassini UltraViolet Imaging Spectrograph (UVIS) provide an excellent view of the planet's auroral emissions, which in turn give an account of the large-scale mag…
In situ observation of magnetic reconnection in the front of bursty bulk flow
Huang, Can; Nakamura, Rumi; Lu, Quanming +5 more
Using the Cluster observation in the magnetotail, we investigate the dynamic processes associated with a bursty bulk flow (BBF) event. The BBF is inferred to be caused by magnetic reconnection proceeding to the lobe region in its tail, called "primary reconnection." On the BBF front, another reconnection was directly encountered by one of the four…