Search Publications
First simultaneous observations of flux transfer events at the high-latitude magnetopause by the Cluster spacecraft and pulsed radar signatures in the conjugate ionosphere by the CUTLASS and EISCAT radars
Balogh, A.; Davies, J. A.; Wild, J. A. +9 more
Cluster magnetic field data are studied during an outbound pass through the post-noon high-latitude magnetopause region on 14 February 2001. The onset of several minute perturbations in the magnetospheric field was observed in conjunction with a southward turn of the interplanetary magnetic field observed upstream by the ACE spacecraft and lagged …
Cluster magnetic field observations in the magnetosheath: four-point measurements of mirror structures
Balogh, A.; Horbury, T. S.; Lucek, E. A. +7 more
The Cluster spacecraft have returned the first simultaneous four-point measurements of the magnetosheath. We present an analysis of data recorded on 10 November 2000, when the four spacecrafts observed an interval of strong mirrorlike activity. Correlation analysis between spacecraft pairs is used to examine the scale size of the mirror structures…
Cluster PEACE observations of electrons during magnetospheric flux transfer events
Coates, A. J.; Balogh, A.; Wilson, R. J. +9 more
During the first quarter of 2001 the apogees of the Cluster spacecraft quartet precessed through midday local times. This provides the first opportunity for 4 spacecraft studies of the bow shock, magnetosheath and the dayside magnetopause current layer and boundary layers. In this paper, we present observations of electrons in the energy range ~ 1…
First results from the Cluster wideband plasma wave investigation
Gurnett, D. A.; Persoon, A. M.; Pickett, J. S. +9 more
In this report we present the first results from the Cluster wideband plasma wave investigation. The four Cluster spacecraft were successfully placed in closely spaced, high-inclination eccentric orbits around the Earth during two separate launches in July August 2000. Each spacecraft includes a wideband plasma wave instrument designed to provide …
Cluster magnetic field observations of the bowshock: Orientation, motion and structure
Balogh, A.; Horbury, T. S.; Lucek, E. A. +7 more
Four spacecraft Cluster magnetic field observations of the low <beta> quasi-perpendicular terrestrial bowshock are presented for the first time. Multiple quasi-perpendicular crossings on 25 December 2000 are analysed. By combining data from the four spacecraft, bowshock orientations and velocities can be calculated. It is shown that, even wh…
Intermittent thermal plasma acceleration linked to sporadic motions of the magnetopause, first Cluster results
Lundin, R.; Sauvaud, J. -A.; Dandouras, I. +17 more
This paper presents the first observations with Cluster of a very dense population of thermal ionospheric ions (H+, He+, O+) locally "accelerated" perpendicularly to the local magnetic field in a region adjacent to the magnetopause and on its magnetospheric side. The observation periods follow a long period of very weak magnetic activity. Recurren…
How to determine the thermal electron density and the magnetic field strength from the Cluster/Whisper observations around the Earth
Krasnoselskikh, V.; Fergeau, P.; Décréau, P. M. E. +11 more
The Wave Experiment Consortium, WEC, is a highly integrated package of five instruments used to study the plasma environment around the Earth. One of these instruments, the Waves of HIgh frequency and Sounder for Probing of Electron density by Relaxation, Whisper, aims at the thermal electron density evaluation and natural wave monitoring in the 4…
Observations of the spatial and temporal structure of field-aligned beam and gyrating ring distributions at the quasi-perpendicular bow shock with Cluster CIS
Lundin, R.; Balsiger, H.; Dandouras, I. +23 more
During the early orbit phase, the Cluster spacecraft have repeatedly crossed the perpendicular Earth's bow shock and provided the first multi-spacecraft measurements. We have analyzed data from the Cluster Ion Spectrometry experiment (CIS), which observes the 3D-ion distribution function of the major species in the energy range of 5 eV to 40 keV w…
Cluster PEACE observations of electrons of spacecraft origin
Fazakerley, A. N.; André, M.; Eriksson, A. +6 more
The two PEACE (Plasma Electron And Current Experiment) sensors on board each Cluster spacecraft sample the electron velocity distribution across the full 4<pi> solid angle and the energy range 0.7 eV to 26 keV with a time resolution of 4 s. We present high energy and angular resolution 3D observations of electrons of spacecraft origin in the…
Oxygen abundance in coronal streamers during solar minimum
Giordano, S.; Antonucci, E.; Marocchi, D.
We present a study of the oxygen abundance relative to hydrogen in the equatorial streamer belt of the solar corona during the recent period of activity minimum. The oxygen abundance is derived from the spectroscopic observations of the outer corona performed during 1996 with the Ultraviolet Coronagraph Spectrometer (SOHO) in the ultra-violet regi…