Search Publications
Cusp as a source for oxygen in the plasma sheet during geomagnetic storms
Dandouras, I.; Klecker, B.; Kistler, L. M. +1 more
We have used the ion composition data from the CIS/CODIF instrument on Cluster to determine how the O+ population in the plasma sheet and the adjacent lobes changes during geomagnetic storms. The Cluster trajectory, which moves over the polar cap, into the lobe, and then into the plasma sheet on each orbit, allows us to track the change…
Structure of magnetic separators and separator reconnection
Parnell, C. E.; Haynes, A. L.; Galsgaard, K.
Magnetic separators are important locations of three-dimensional magnetic reconnection. They are field lines that lie along the edges of four flux domains and represent the intersection of two separatrix surfaces. Since the intersection of two surfaces produces an X-type structure, when viewed along the line of intersection, the global three-dimen…
“Island surfing” mechanism of electron acceleration during magnetic reconnection
Fujimoto, M.; Phan, T. D.; Shinohara, I. +1 more
One of the key unresolved problems in the study of space plasmas is to explain the production of energetic electrons as magnetic field lines “reconnect” and release energy in an explosive manner. Recent observations suggest possible roles played by small-scale magnetic islands in the reconnection region, but their precise roles and the exact mecha…
Geomagnetic signatures of current wedge produced by fast flows in a plasma sheet
Dunlop, Malcolm; Zhang, Tielong; Cao, Jin-Bin +10 more
This paper uses the plasma data from Cluster and TC-1 and geomagnetic data to study the geomagnetic signatures of the current wedge produced by fast-flow braking in the plasma sheet. The three fast flows studied here occurred in a very quiet background and were accompanied by no (or weak) particle injections, thus avoiding the influences from othe…
Statistical study of O+ transport from the cusp to the lobes with Cluster CODIF data
Dandouras, I.; Klecker, B.; Kistler, L. M. +3 more
Ionospheric origin O+ accelerated in the cusp/cleft region convects over the polar cap and flows along open field lines to the tail lobes. Some O+ in the lobes enters the near-Earth plasma sheet where it is then convected to the inner magnetosphere, while some O+ ends up in the distant tail where it is lost. In ord…
Observations of energetic electrons up to 200 keV associated with a secondary island near the center of an ion diffusion region: A Cluster case study
Wang, Shui; Li, Xing; Huang, Can +2 more
An antiparallel reconnection event is recognized in the magnetotail, and a secondary island with a strong core magnetic field is identified near the center of the ion diffusion region. In the island, the electron density peaks in the outer region while the dip is in the core region with a strong core magnetic field. A strong electron beam parallel…
Sun to 1 AU propagation and evolution of a slow streamer-blowout coronal mass ejection
Luhmann, J. G.; Li, Y.; Lynch, B. J. +4 more
We present a comprehensive analysis of the evolution of the classic, slow streamer-blowout CME of 1 June 2008 observed by the STEREO twin spacecraft to infer relevant properties of the pre-eruption source region which includes a substantial portion of the coronal helmet streamer belt. The CME was directed ∼40° East of the Sun-Earth line and the He…
H+ and O+ content of the plasma sheet at 15-19 Re as a function of geomagnetic and solar activity
Dandouras, I.; Klecker, B.; Kistler, L. M. +3 more
We have used the ion composition data from the CIS/CODIF instrument on the Cluster spacecraft to determine how the H+ and O+ contribution to the plasma sheet density changes as a function of geomagnetic conditions and solar activity. The Cluster spacecraft are in a polar orbit that cut through the equatorial plasma sheet at ∼…
Multispacecraft observation of electron pitch angle distributions in magnetotail reconnection
Wang, Shui; Huang, Can; Lu, Quanming +1 more
In this paper, we present Cluster observations of a magnetotail reconnection event without the presence of an obvious guide magnetic field and analyze electron pitch angle distributions in the vicinity of the X line and the outflow region, respectively. In the vicinity of the X line, at lower energies the distributions are highly anisotropic (fiel…
Electron acceleration signatures in the magnetotail associated with substorms
Fazakerley, A. N.; Daly, P. W.; Vaivads, A. +13 more
We present Cluster multisatellite observations of accelerated electrons in the near-Earth magnetotail associated with substorms. We found that the hardest electron energy spectra appear in the earliest stage of substorm expansion in the near-Earth tail region and that they gradually become softer during the events. Enhancement of the high-energy e…