Search Publications
Energetic electrons along the high-latitude magnetopause
Daly, P. W.; Haaland, S. E.; Kronberg, E. A. +2 more
A case study is presented to determine the source of the energetic electron layer frequently observed along the high-latitude magnetopause. Measurements by the Cluster spacecraft show bursts of field-aligned electrons occurring during time periods with high potential for dayside reconnection. These properties are compared with the expected signatu…
Multispacecraft observations of the terrestrial bow shock and magnetopause during extreme solar wind disturbances
Erdös, G.; Vennerstrom, S.; Tátrallyay, M. +2 more
Three events are discussed from the declining phase of the last solar cycle when the magnetopause and/or the bow shock were observed unusually close to the Earth due to major interplanetary disturbances. The observed extreme locations of the discontinuities are compared with the predictions of three magnetopause and four bow shock models which des…
Multi-spacecraft observations of small-scale fluctuations in density and fields in plasmaspheric plumes
Mouikis, C. G.; Khotyaintsev, Yu. V.; Torbert, R. B. +6 more
In this event study, small-scale fluctuations in plasmaspheric plumes with time scales of ~10 s to minutes in the spacecraft frame are examined. In one event, plasmaspheric plumes are observed by Cluster, while IMAGE measured density enhancement at a similar location. Fluctuations in density exist in plumes as detected by Cluster and are accompani…
More about arc-polarized structures in the solar wind
Haaland, S.; Paschmann, G.; Sonnerup, B.
We report results from a Cluster-based study of the properties of 28 arc-polarized magnetic structures (also called rotational discontinuities) in the solar wind. These Alfvénic events were selected from the database created and analyzed by Knetter (2005) by use of criteria chosen to eliminate ambiguous cases. His studies showed that standard, fou…
Electron pitch angle distribution during magnetic reconnection diffusion region observations in the Earth's magnetotail
Eastwood, J. P.; Taylor, M. G. G. T.; Borg, A. L.
The Earth's magnetosphere provides an excellent laboratory for magnetic reconnection research. In particular, the magnetotail current sheet that is formed between the interface of the similar Northern and Southern Hemispheres of the magnetotail provides a relatively stable symmetric reconnection configuration that can be used to study basic aspect…
Remote estimation of reconnection parameters in the Earth's magnetotail: model and observations
Glassmeier, K. -H.; Kubyshkin, I. V.; Nakamura, R. +8 more
We develop a method to estimate the reconnected magnetic flux and the location of the reconnection site using properties of magnetic field and plasma velocity disturbances in the regions surrounding the reconnection plasma flow. Our analysis is based on a 3-D non-steady reconnection model with a finite-sized X-line length. In this framework, we ob…
Oxygen ion energization by waves in the high altitude cusp and mantle
Waara, M.; Nilsson, H.; Slapak, R. +2 more
We present a comparative study of low frequency electric field spectral densities and temperatures observed by the Cluster spacecraft in the high altitude cusp/mantle region. We compare the relation between the O+ temperature and wave intensity at the oxygen gyrofrequency at each measurement point and find a clear correlation. The trend…
Interball-1 observations of flux transfer events
Sibeck, D. G.; Korotova, G. I.; Petrov, V. I.
We present the results of a survey of 807 FTEs observed by Interball-1 on the mid- and high-latitude dayside and flank magnetopause. Dayside magnetosheath events show a strong tendency to occur for southward magnetosheath magnetic fields suggesting origin via component (or perhaps antiparallel) reconnection near the equatorial plane. Flank FTEs oc…
A statistical and event study of magnetotail dipolarization fronts
Nakamura, R.; Baumjohann, W.; Volwerk, M. +2 more
A study of dipolarization fronts of the Earth's magnetotail has been performed using seven years (2001-2007) of Cluster data. Events both with and without high-speed earthward flows are included. A superposed epoch analysis of the data shows that the dipolarization is preceeded by a decrease of Bz before the increase. The duration of th…
Magnetopause reconnection across wide local time
Berchem, J.; Eastwood, J. P.; Lavraud, B. +19 more
During April to July 2007 a combination of 10 spacecraft provided simultaneous monitoring of the dayside magnetopause across a wide range of local times. The array of four Cluster spacecraft, separated at large distances (10 000 km), were traversing the dawn-side magnetopause at high and low latitudes; the five THEMIS spacecraft were often in a 4 …