Search Publications
Energetic electron acceleration in the downstream reconnection outflow region
Balogh, A.; RèMe, H.; Daly, P. W. +5 more
Energetic electrons in an earthward reconnection outflow region have been observed by Cluster/Research with Adaptive Particle Imaging Detectors. We found a good correlation between the energetic electron enhancement and a normal magnetic field (Bz) enhancement within a 0.25-s time resolution. The large normal magnetic field is thought t…
Multi-point observations of the Hall electromagnetic field and secondary island formation during magnetic reconnection
Balogh, A.; Dandouras, I.; Eastwood, J. P. +7 more
A key feature of collisionless magnetic reconnection is the formation of Hall magnetic and electric field structure in the vicinity of the diffusion region. Here we present multi-point Cluster observations of a reconnection event in the near-Earth magnetotail where the diffusion region was nested by the Cluster spacecraft; we compare observations …
Saturnian magnetospheric dynamics: Elucidation of a camshaft model
Southwood, D. J.; Kivelson, M. G.
Periodic modulation of magnetospheric phenomena at Earth and Jupiter results principally from the tilt of the dipole axis relative to the rotation axis. Saturn's nearly aligned dipole moment is tilted by less than 0.5° from the spin axis, yet the power of radio-frequency emissions, the orientation of the magnetic field, and many properties of the …
Cassini observations of the variation of Saturn's ring current parameters with system size
Russell, C. T.; Dougherty, M. K.; Alexeev, I. I. +4 more
We have examined residual magnetic field vectors observed in Saturn's magnetosphere during the first 2 years of the Cassini mission and have fit them to a simple axisymmetric model of the ring current in the middle magnetosphere. We then examine the variations of the ring current parameters with size of the magnetosphere. In addition, we obtain se…
V arc interplanetary coronal mass ejections observed with the Solar Mass Ejection Imager
Webb, D. F.; Kahler, S. W.
Since February 2003, the Solar Mass Ejection Imager (SMEI) has been observing interplanetary coronal mass ejections (ICMEs) at solar elongation angles $\epsilon$ > 20°. The ICMEs generally appear as loops or arcs in the sky, but five show distinct outward concave shapes that we call V arcs. We expect to observe some V arcs, formed by trailing e…
Cluster observations of waves in the whistler frequency range associated with magnetic reconnection in the Earth's magnetotail
Dandouras, I.; Lucek, E.; RèMe, H. +7 more
On 21 August 2002 the Cluster spacecraft encountered a quasi-collisionless magnetic reconnection event when it crossed the plasma sheet. Prior to the southward turning of magnetic field in the tailward flow, the weak whistler waves were first observed. The burst of whistler waves appeared about 30 s earlier than the southward turning. During magne…
Cassini Ion and Neutral Mass Spectrometer data in Titan's upper atmosphere and exosphere: Observation of a suprathermal corona
Luhmann, J. G.; Johnson, R. E.; Leblanc, F. +10 more
The neutral nitrogen and methane measurements made by Ion and Neutral Mass Spectrometer during Cassini flybys TA, TB, and T5 in Titan's upper atmosphere and exosphere are presented. Large horizontal variations are observed in the total density, recorded to be twice as large during TA as during T5
Understanding the escape of water from Enceladus
Johnson, R. E.; Sittler, E. C.; Smith, H. T. +3 more
On 14 July 2005, Cassini passed within 175 km of Enceladus' surface enabling a direct in situ measurement of water escaping from the surface by the Ion and Neutral Mass Spectrometer (INMS) and the observation of a stellar occultation by the Ultraviolet Spectrometer (UVIS). We have developed a three-dimensional, Monte Carlo neutral model to simulta…
Thinning and stretching of the plasma sheet
Petrukovich, A. A.; Balogh, A.; RèMe, H. +3 more
With Cluster observations in the magnetotail we study dynamics of plasma sheet thinning and stretching during 39 intervals associated with substorm growth phases. The cross-tail current density and normal magnetic field generally scale as Bn ∼ TpNp1/2/J0, but with frequent transient variations…
Electron sources in Saturn's magnetosphere
André, N.; Coates, A. J.; Dougherty, M. K. +11 more
We investigate the sources of two different electron components in Saturn's inner magnetosphere (5 < L < 12 Rs) by performing phase space density (f(v)) analyses of electron measurements made by the Cassini CAPS instrument (1 eV to 28 keV). Because pitch angle distributions indicate that the traditional single particle invariants of gyration…