Search Publications
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…
Proton velocity distribution in thin current sheets: Cluster observations and theory of transient trajectories
Petrukovich, A. A.; Zelenyi, L. M.; Nakamura, R. +1 more
The structure of thin current sheets in the Earth magnetotail is studied on the basis of 43 crossings by Cluster spacecraft. Current sheet embedding is described as the ratio of the magnitudes of magnetic field at the thin current sheet boundary and in the lobe. This ratio is found to be ∼0.4 on average. The proton population consists of the curre…
Understanding large SEP events with the PATH code: Modeling of the 13 December 2006 SEP event
Verkhoglyadova, O. P.; Cohen, C. M. S.; Mewaldt, R. A. +7 more
The Particle Acceleration and Transport in the Heliosphere (PATH) numerical code was developed to understand solar energetic particle (SEP) events in the near-Earth environment. We discuss simulation results for the 13 December 2006 SEP event. The PATH code includes modeling a background solar wind through which a CME-driven oblique shock propagat…
Magnetic field oscillations near the planetary period in Saturn's equatorial magnetosphere: Variation of amplitude and phase with radial distance and local time
Dougherty, M. K.; Andrews, D. J.; Cowley, S. W. H. +1 more
We present an analysis of the ∼11 h oscillations in Saturn's near-equatorial magnetic field, using Cassini data acquired during 2004-2007. We assume the oscillation period is given by the magnetic phase model derived by Provan et al. (2009) over the same interval, and use this to combine the data to determine the variation of the oscillation ampli…
Cluster observations of simultaneous resonant interactions of ULF waves with energetic electrons and thermal ion species in the inner magnetosphere
Zong, Q. -G.; Reme, H.; Korth, A. +6 more
In this study, we report in situ observations on the simultaneous periodic modulations in the drifting energetic electrons (∼100 keV) and in the bouncing thermal ion species (O+ at ∼4.5 keV and H+ at ∼280 eV) with the same frequency of 3.3 mHz during the storm recovery phase on 21 October 2001. The Cluster fleet was traveling…
Cluster observations of bidirectional beams caused by electron trapping during antiparallel reconnection
Fazakerley, A.; Egedal, J.; Lê, A. +4 more
So-called bidirectional electron beams have been observed by a number of spacecraft missions mainly in the inflow of reconnection regions. Here we show that these beam-like features in the electron distribution function are explained by electron trapping. The trapping is mainly controlled by a positive acceleration potential, Φ$\parallel$
Detection and measurement of ice grains and gas distribution in the Enceladus plume by Cassini's Ion Neutral Mass Spectrometer
Waite, J. H.; Teolis, B. D.; Magee, B. A. +2 more
We report on the measurements of the Cassini Ion Neutral Mass Spectrometer (INMS) of the density and structure of Enceladus' south polar plume during the E3 and E5 flybys on 12 March and 9 October 2008. Using a Monte Carlo simulation, we analyze the dependence of the INMS gas inlet transmittance on spacecraft pointing and the effect on the measure…