Search Publications
Cusp observations during a sequence of fast IMF BZ reversals
Pitout, F.; Davies, J. A.; Lockwood, M. +6 more
In recent years, a large number of papers have reported the response of the cusp to solar wind variations under conditions of northward or southward Interplanetary Magnetic Field (IMF) Z-component (BZ). These studies have shown the importance of both temporal and spatial factors in determining the extent and morphology of the cusp and t…
Dual source populations of substorm-associated ring current ions
Yamauchi, M.; Dandouras, I.; Rème, H. +1 more
Sources of low-energy ring current ions in the early morning sector (eastward drifting energy domain of about <5 keV) are examined using both statistical analyses and numerical tracing methods (phase-space mapping and simulation). In about 90% of Cluster perigee traversals at 02~07 local time, these low-energy ring current ions have dual ion po…
Scale size and life time of energy conversion regions observed by Cluster in the plasma sheet
Dandouras, I.; Hamrin, M.; Norqvist, P. +4 more
In this article, and in a companion paper by Hamrin et al. (2009) [Occurrence and location of concentrated load and generator regions observed by Cluster in the plasma sheet], we investigate localized energy conversion regions (ECRs) in Earth's plasma sheet. From more than 80 Cluster plasma sheet crossings (660 h data) at the altitude of about 15-…
Magnetospheric solitary structure maintained by 3000 km/s ions as a cause of westward moving auroral bulge at 19 MLT
Lundin, R.; Yamauchi, M.; Balogh, A. +11 more
In the evening equatorial magnetosphere at about 4 RE geocentric distance and 19 MLT, the four Cluster spacecraft observed a solitary structure with a width of about 1000~2000 km in the propagation direction. The solitary structure propagates sunward with about 5~10 km/s carrying sunward electric field (in the propagation direction) of …
Outflowing protons and heavy ions as a source for the sub-keV ring current
Lundin, R.; Yamauchi, M.; Dandouras, I. +11 more
Data from the Cluster CIS instrument have been used for studying proton and heavy ion (O+ and He+) characteristics of the sub-keV ring current. Thirteen events with dispersed heavy ions (O+ and He+) were identified out of two years (2001 and 2002) of Cluster data. All events took place during rather geom…
Multispacecraft observations of a prominence eruption
Andretta, V.; Del Zanna, G.; Bemporad, A. +2 more
On 9 May 2007 a prominence eruption occurred at the West limb. Remarkably, the event was observed by the STEREO/EUVI telescopes and by the HINODE/EIS and SOHO/UVCS spectrometers. We present results from all these instruments. High-cadence (~37 s) data from STEREO/EUVI A and B in the He II λ304 line were used to study the 3-D shape and expansion of…
Formation of lower-hybrid solitary structures by modulational interaction between lower-hybrid and dispersive Alfvén waves
André, M.; Stenberg, G.; Eriksson, A. I. +1 more
We investigate the possibility that lower-hybrid solitary structures (LHSS), which are frequently observed in the Earth's ionosphere and magnetosphere, are formed as a result of a modulational interaction between lower-hybrid and dispersive Alfvén waves of initially small amplitude. A large amplitude lower-hybrid pump wave can excite density struc…
Foreshock-like density cavity in the outflow region of magnetotail reconnection
Dandouras, I.; Rème, H.; Cao, J. B. +4 more
During Cluster spacecraft crossing of the magnetotail, a novel density depleted cavity in association with magnetic compressions in the outflow region of reconnection was observed. It contains intense reflected field-aligned particles, which are produced by a generation mechanism similar to that of the terrestrial foreshock, and hence manifests a …
Solar off-limb line widths with SUMER: revised value of the non-thermal velocity and new results
Dolla, L.; Solomon, J.
Alfvén waves and ion-cyclotron absorption of high-frequency waves are frequently brought into models devoted to coronal heating and fast solar-wind acceleration. Signatures of ion-cyclotron resonance have already been observed in situ in the solar wind and in the upper corona. In the lower corona, one can use the line profiles to infer the ion tem…
Mirror waves and mode transition observed in the magnetosheath by Double Star TC-1
Zhang, T. L.; Wang, C.; Volwerk, M. +2 more
The Double Star TC-1 magnetosheath pass on 26 February 2004 is used to investigate magnetic field fluctuations. Strong compressional signatures which last for more than an hour have been found near the magnetopause behind a quasi-perpendicular bow shock. These compressional structures are most likely mirror mode waves. There is a clear wave transi…