Search Publications
Multi-spacecraft measurement of anisotropic power levels and scaling in solar wind turbulence
Horbury, T. S.; Osman, K. T.
Measurements by the four Cluster spacecraft in the solar wind are used to determine quantitatively the field-aligned anisotropy of magnetohydrodynamic inertial range turbulence power levels and spectral indexes. We find, using time-lagged second order structure functions, that the spectral index is near 2 around the field-parallel direction, which…
Cluster and ACE observations of phase synchronization in intermittent magnetic field turbulence: a comparative study of shocked and unshocked solar wind
Chian, A. C. -L.; Miranda, R. A.
We apply two distinct nonlinear techniques, kurtosis and phase coherence index, to analyze the modulus of interplanetary magnetic field data |B| measured by Cluster and ACE spacecraft from 1 to 3 February 2002. High degree of phase synchronization is found across a wide range of time scales, from 1 s to 104 s, in the magnetic field fluc…
Signatures of interchange reconnection: STEREO, ACE and Hinode observations combined
Sauvaud, J. -A.; Luhmann, J. G.; van Driel-Gesztelyi, L. +8 more
Combining STEREO, ACE and Hinode observations has presented an opportunity to follow a filament eruption and coronal mass ejection (CME) on 17 October 2007 from an active region (AR) inside a coronal hole (CH) into the heliosphere. This particular combination of "open" and closed magnetic topologies provides an ideal scenario for interchange recon…
Oxygen ion escape from Venus in a global hybrid simulation: role of the ionospheric O+ ions
Kallio, E.; Janhunen, P.; Barabash, S. +4 more
We study the solar wind induced oxygen ion escape from Venus' upper atmosphere and the Venus Express observations of the Venus-solar wind interaction by the HYB-Venus hybrid simulation code. We compare the simulation to the magnetic field and ion observations during an orbit of nominal upstream conditions. Further, we study the response of the ind…
Reconstruction of a large-scale reconnection exhaust structure in the solar wind
Farrugia, C. J.; Hu, Q.; Teh, W. -L. +1 more
We recover two-dimensional (2-D) magnetic field and flow field configurations from three spacecraft encounters with a single large-scale reconnection exhaust structure in the solar wind, using a new reconstruction method (Sonnerup and Teh, 2008) based on the ideal single-fluid MHD equations in a steady-state, 2-D geometry. The reconstruction is pe…
On the triggering of auroral substorms by northward turnings of the interplanetary magnetic field
Wild, J. A.; Woodfield, E. E.; Morley, S. K.
Some studies over the last decade have indicated that the instability responsible for substorm expansion phase onset may require an external trigger such as a northward turning of the interplanetary magnetic field (IMF). Statistical investigations have lead to contrasting interpretations regarding the relationship between proposed solar wind trigg…
Titan's ionosphere in the magnetosheath: Cassini RPWS results during the T32 flyby
Gurnett, D. A.; Garnier, P.; Krimigis, S. M. +11 more
The Cassini mission has provided much information about the Titan environment, with numerous low altitude encounters with the moon being always inside the magnetosphere. The only encounter taking place outside the magnetopause, in the magnetosheath, occurred the 13 June 2007 (T32 flyby). This paper is dedicated to the analysis of the Radio and Pla…
Plasma transport in the magnetotail lobes
Haaland, S.; Lybekk, B.; Pedersen, A. +4 more
The Earth's magnetosphere is populated by particles originating from the solar wind and the terrestrial ionosphere. A substantial fraction of the plasma from these sources are convected through the magnetotail lobes. In this paper, we present a statistical study of convective plasma transport through the Earth's magnetotail lobes for various geoma…
Cluster survey of the mid-altitude cusp - Part 2: Large-scale morphology
Escoubet, C. P.; Pitout, F.; Dandouras, I. +1 more
In this second part of our statistical study of the mid-altitude cusp, we compare the cusp morphology, as seen in the Cluster ion spectrometer (CIS), to the interplanetary magnetic field (IMF) orientation. We first recall the method we have used a) to define the cusp properties, b) to sort IMF conditions or behaviour in classes, c) to determine th…
3-D reconstructions of the early-November 2004 CDAW geomagnetic storms: analysis of Ooty IPS speed and density data
Jackson, B. V.; Buffington, A.; Hick, P. P. +4 more
Interplanetary scintillation (IPS) remote-sensing observations provide a view of the solar wind covering a wide range of heliographic latitudes and heliocentric distances from the Sun between ~0.1 AU and 3.0 AU. Such observations are used to study the development of solar coronal transients and the solar wind while propagating out through interpla…