Search Publications
Flapping motions of the magnetotail current sheet excited by nonadiabatic ions
Dandouras, I.; Rème, H.; Cao, J. B. +3 more
Observations by the Cluster spacecraft on 3 August 2004 are presented as an example of flapping motions of the magnetotail current sheet excited by nonadiabatic ions. It is found that the current sheet up-down motions are exactly corresponding to alternating hemispherical asymmetries of the bouncing ion population. We show that those hemisphere-as…
Saturn's giant storm and global radiant energy
West, Robert A.; Baines, Kevin H.; Nixon, Conor A. +11 more
We analyze the relationship between Saturn's radiant energies and the 2010 giant storm with the Cassini observations. The storm increased the emitted power in a wide latitudinal band (20-55°N) with a maximum change of 9.2 ± 0.1% around 45°N from 2010 to 2011. Such a regional change caused the global-average emitted power to increase by ~2.0 ± 0.2%…
Momentum transfer from solar wind to interplanetary field enhancements inferred from magnetic field draping signatures
Lai, H. R.; Russell, C. T.; Jia, Y. D. +2 more
Characterized by a cusp-shaped enhancement in the magnetic field strength, the magnetic structure in the solar wind, called an interplanetary field enhancement (IFE), has been investigated since its discovery. To understand its three-dimensional magnetic field geometry, we study an IFE detected by five spacecraft simultaneously. Field lines are se…
Hall and finite Larmor radius effects on the dipolarization fronts associated with interchange instability
Zhang, T. L.; Nakamura, R.; Dunlop, M. W. +3 more
In this paper, we established a Hall-finite Larmor radius (FLR) MHD model by including Hall and finite Larmor radius (FLR) effects to study the dipolarization fronts (DFs) produced by the interchange instability in the magnetotail. The results indicate that the Hall effect on the scale of inertial length determines the distributions of electric fi…
Statistics and accuracy of magnetic null identification in multispacecraft data
André, M.; Vaivads, A.; Khotyaintsev, Yu. V. +2 more
Complex magnetic topologies are ubiquitous in astrophysical plasmas. Analyzing magnetic nulls, regions of vanishing magnetic field, is one way to characterize 3-D magnetic topologies. Magnetic nulls are believed to be important in 3-D reconnection and turbulence. In the vicinity of a null, plasma particles become unmagnetized and can be accelerate…
Solar illumination control of ionospheric outflow above polar cap arcs
Dandouras, I.; Fear, R. C.; De Keyser, J. +4 more
We measure the flux density, composition, and energy of outflowing ions above the polar cap, accelerated by quasi-static electric fields parallel to the magnetic field and associated with polar cap arcs, using Cluster. Mapping the spacecraft position to its ionospheric foot point, we analyze the dependence of these parameters on the solar zenith a…
A new upper limit to the field-aligned potential near Titan
Coates, Andrew J.; Waite, J. Hunter; Jones, Geraint H. +1 more
Neutral particles dominate regions of the Saturn magnetosphere and locations near several of Saturn's moons. Sunlight ionizes neutrals, producing photoelectrons with characteristic energy spectra. The Cassini plasma spectrometer electron spectrometer has detected photoelectrons throughout these regions, where photoelectrons may be used as tracers …
Ten years of Martian nitric oxide nightglow observations
Montmessin, Franck; Bertaux, Jean-Loup; Stiepen, Arnaud +2 more
We present 10 years of Martian NO nightglow Spectroscopy for Investigation of Characteristics of the Atmosphere of Mars observations in limb and stellar occultation modes. The NO nightglow is used as a tracer of the summer-to-winter hemispherical circulation in the upper atmosphere of Mars. Its distribution roughly follows the curve latitude = -80…
Identification of the dominant ULF wave mode and generation mechanism for obliquely propagating waves in the Earth's foreshock
Stasiewicz, K.; Grzesiak, M.; Karimabadi, H. +3 more
We discuss mechanisms of the generation of ultralow frequency (ULF) upstream waves in the terrestrial foreshock that are essential for the acceleration of ions in space plasmas. The analysis is based on global hybrid kinetic simulations of the magnetosphere that provide realistic environment for the growth of the ULF waves in a quasi-radial config…
The equivalent slab thickness of Mars' ionosphere: Implications for thermospheric temperature
Gurnett, D.; Mouginot, J.; Kofman, W. +4 more
The total electron content (TEC) of a planetary ionosphere is dominated by plasma near and above the height of maximum electron density (Nmax). The ratio TEC/Nmax represents the thickness (τ) of a TEC slab of uniform density (Nmax). For a photochemical ionosphere, τ relates to the scale height (H = kT/mg) of the io…