Search Publications
Cassini observations of Saturn's southern polar cusp
Coates, A. J.; Krupp, N.; Russell, C. T. +15 more
The magnetospheric cusps are important sites of the coupling of a magnetosphere with the solar wind. The combination of both ground- and space-based observations at Earth has enabled considerable progress to be made in understanding the terrestrial cusp and its role in the coupling of the magnetosphere to the solar wind via the polar magnetosphere…
Conjugate observations of quasiperiodic emissions by the Cluster, Van Allen Probes, and THEMIS spacecraft
Pickett, J. S.; Kurth, W. S.; Santolík, O. +3 more
We present results of a detailed analysis of two electromagnetic wave events observed in the inner magnetosphere at frequencies of a few kilohertz, which exhibit a quasiperiodic (QP) time modulation of the wave intensity. The events were observed by the Cluster and Van Allen Probes spacecraft and in one event also by the THEMIS E spacecraft. The s…
Field-aligned currents in Saturn's magnetosphere: Local time dependence of southern summer currents in the dawn sector between midnight and noon
Coates, A. J.; Dougherty, M. K.; Alexeev, I. I. +6 more
We examine and compare the magnetic field perturbations associated with field-aligned ionosphere-magnetosphere coupling currents at Saturn, observed by the Cassini spacecraft during two sequences of highly inclined orbits in 2006/2007 and 2008 under late southern summer conditions. These sequences explore the southern currents in the dawn-noon and…
First in situ evidence of electron pitch angle scattering due to magnetic field line curvature in the Ion diffusion region
Lavraud, B.; Liu, Z. X.; Rong, Z. J. +8 more
Theory predicts that the first adiabatic invariant of a charged particle may be violated in a region of highly curved field lines, leading to significant pitch angle scattering for particles whose gyroradius are comparable to the radius of the magnetic field line curvature. This scattering generates more isotropic particle distribution functions, …
Commentary on accessing 3-D currents in space: Experiences from Cluster
Dunlop, M. W.; Haaland, S.; Dong, X. -C. +1 more
The curlometer was introduced to estimate the electric current density from four-point measurements in space; anticipating the realization of the four spacecraft Cluster mission which began full science operations in February 2001. The method uses Ampère's law to estimate current from the magnetic field measurements, suitable for the high-conducti…
Characterization of Saturn's bow shock: Magnetic field observations of quasi-perpendicular shocks
Dougherty, M. K.; Masters, A.; Sulaiman, A. H.
Collisionless shocks vary drastically from terrestrial to astrophysical regimes resulting in radically different characteristics. This poses two complexities. First, separating the influences of these parameters on physical mechanisms such as energy dissipation. Second, correlating observations of shock waves over a wide range of each parameter, e…
An induced global magnetic field looping around the magnetotail of Venus
Barabash, Stas; Zhang, Tielong; Rong, Zhaojin +8 more
Venus serves as the prototype of solar wind interaction with unmagnetized planetary bodies with atmospheres. It has no intrinsic dipole or crustal magnetic field; the only magnetic field is believed to be formed by the draped interplanetary magnetic field (IMF). However, the large-scale magnetic field observed over the north polar region of Venus …
A statistical study of magnetospheric ion composition along the geomagnetic field using the Cluster spacecraft for L values between 5.9 and 9.5
Dandouras, I.; Sandhu, J. K.; Yeoman, T. K. +1 more
Using ion density data obtained by the CODIF (ion Composition and Distribution Function analyser) instrument on board the Cluster spacecraft, for the interval spanning 2001-2005, an empirical model describing the average ion mass distribution along closed geomagnetic field lines is determined. The empirical model describes the region spanning 5.9≤…
Modulation of the substorm current wedge by bursty bulk flows: 8 September 2002—Revisited
Nakamura, R.; Sergeev, V. A.; Milan, S. E. +12 more
The ultimate formation mechanism of the substorm current wedge (SCW) remains to date unclear. In this study, we investigate its relationship to plasma flows at substorm onset and throughout the following expansion phase. We revisit the case of 8 September 2002, which has been defined as "one of the best textbook examples of a substorm" because of …
Statistics of energetic electrons in the magnetotail reconnection
Xu, Xiaojun; Huang, Shiyong; Zhou, Meng +5 more
Magnetic reconnection has long been regarded as an important site for producing energetic electrons in solar terrestrial and astrophysical plasmas. The motivation of this paper is to provide the average properties of energetic electrons in reconnection region, which are crucial for understanding electron energization mechanism but are rarely known…