Search Publications

Statistical analysis of plasmaspheric plumes with Cluster/WHISPER observations

de Keyser, J.; Décréau, P. M. E.; Vallières, X. +2 more

Plasmaspheric plumes have been routinely observed by the four Cluster spacecraft. This paper presents a statistical analysis of plumes observed during five years (from 1 February 2001 to 1 February 2006) based on four-point measurements of the plasmasphere (outside 4 Earth radii) as it is sampled by the spacecraft in a narrow local time sector bef…

Two-spacecraft reconstruction of a magnetic cloud and comparison to its solar source

Möstl, C.; Farrugia, C. J.; Temmer, M. +5 more

This paper compares properties of the source region with those inferred from satellite observations near Earth of the magnetic cloud which reached 1 AU on 20 November 2003. We use observations from space missions SOHO and TRACE together with ground-based data to study the magnetic structure of the active region NOAA 10501 containing a highly curve…

A review of the quantitative links between CMEs and magnetic clouds

Démoulin, P.

Magnetic clouds (MCs), and more generally, interplanetary coronal mass ejections (ICMEs), are believed to be the interplanetary counterparts of CMEs. The link has usually been shown by taking into account the CME launch position on the Sun, the expected time delay and by comparing the orientation of the coronal and interplanetary magnetic field. M…

IMF dependence of high-latitude thermospheric wind pattern derived from CHAMP cross-track measurements

Liu, H.; Haaland, S. E.; Förster, M. +2 more

Neutral thermospheric wind pattern at high latitudes obtained from cross-track acceleration measurements of the CHAMP satellite above both North and South polar regions are statistically analyzed in their dependence on the Interplanetary Magnetic Field (IMF) direction in the GSM y-z plane (clock angle). We compare this dependency with magnetospher…

The azimuthal extent of three flux transfer events

Dandouras, I.; Fazakerley, A. N.; Lucek, E. A. +3 more

In early 2006, the Cluster spacecraft crossed the dayside magnetopause twice each orbit with the spacecraft at their largest separation of the entire mission (~10 000 km). In this paper, we present in situ observations at this separation size of flux transfer events (FTEs), which are a signature of transient or time-varying magnetopause reconnecti…

Effects on magnetic reconnection of a density asymmetry across the current sheet

André, M.; Khotyaintsev, Y.; Vaivads, A. +8 more

Magnetic configurations of the tilted current sheets in magnetotail

Malova, H. V.; Lucek, E.; Carr, C. +5 more

In this research, the geometrical structures of tilted current sheet and tail flapping waves have been analysed based on multiple spacecraft measurements and some features of the tilted current sheets have been made clear for the first time. The geometrical features of the tilted current sheet revealed in this investigation are as follows: (1) The…

Auroral current systems in Saturn's magnetosphere: comparison of theoretical models with Cassini and HST observations

Coates, A. J.; Dougherty, M. K.; Nichols, J. D. +7 more

The first simultaneous observations of fields and plasmas in Saturn's high-latitude magnetosphere and UV images of the conjugate auroral oval were obtained by the Cassini spacecraft and the Hubble Space Telescope (HST) in January 2007. These data have shown that the southern auroral oval near noon maps to the dayside cusp boundary between open and…

What is the best method to calculate the solar wind propagation delay?

Haaland, S.; Mailyan, B.; Munteanu, C.

We present a statistical study of propagation times of solar wind discontinuities between Advanced Composition Explorer (ACE) spacecraft orbiting the L1 libration point and the Cluster quartet of spacecraft near the Earth's magnetopause. The propagation times for almost 200 events are compared with the predicted times from four different models. T…

Review on the solar spectral variability in the EUV for space weather purposes

Auchère, F.; Kretzschmar, M.; Dudok de Wit, T. +4 more

The solar XUV-EUV flux is the main energy source in the terrestrial diurnal thermosphere: it produces ionization, dissociation, excitation and heating. Accurate knowledge of this flux is of prime importance for space weather. We first list the space weather applications that require nowcasting and forecasting of the solar XUV-EUV flux. We then rev…