Search Publications
Semiempirically derived heating function of the corona heliosphere during the Whole Sun Month
Sittler, E. C.; Guhathakurta, M.; Ofman, L.
In spite of many recent developments in observations and models of the solar corona, the exact form of the heating function of the solar wind plasma is unknown. Here we attempt to make some progress on that problem by applying a previously developed simplified magnetohydrodynamic model to a unique synthesis of remote sensing coronal observations f…
Plasma wave source location using CLUSTER as a spherical wave telescope
Glassmeier, K. -H.; Motschmann, U.; FräNz, M. +3 more
The use of sensor arrays in space opens up the possibility to investigate the source location of plasma waves. In order to do so, we generalize the wave telescope technique to use spherical waves instead of plane waves. The new tool determines the center of the wavefronts locally measured by the sensor array. This virtual source can be related wit…
Source location of the wedge-like dispersed ring current in the morning sector during a substorm
Lundin, R.; Yamauchi, M.; Balogh, A. +8 more
Source of wedge-like dispersed sub-keV ring current ions (wedge-like structure) is investigated using Cluster CIS data. Statistics from nearly 550 traversals show that the wedge-like structure with upper energy extending to ordinary energy of ring current is found mostly in the morning sector whereas those limited within sub-keV range are found mo…
Success rate of predicting the heliospheric magnetic field polarity with Michelson Doppler Imager (MDI) synoptic charts
Liu, Y.; Hoeksema, J. T.; Scherrer, P. H. +1 more
The photospheric and heliospheric magnetic fields have been continuously observed at the L1 point by the Michelson Doppler Imager (MDI) on the Solar and Heliospheric Observatory (SOHO) and Wind and the Advanced Composition Explorer (ACE) spacecraft since 1996. The combined observations of the photospheric and heliospheric magnetic fields make it p…
Are high-latitude forward-reverse shock pairs driven by CME overexpansion?
Zurbuchen, T. H.; Manchester, W. B.
During its passage through the high-latitude heliosphere, Ulysses observed interplanetary coronal mass ejections (ICMEs) bounded by shocks. These forward-reverse shock pairs have only been observed at high latitude in the fast solar wind. It has been suggested (e.g., Gosling et al., 1995) that these shock pairs are the result of expansion of coron…
Kinetic signatures during a quasi-continuous lobe reconnection event: Cluster Ion Spectrometer (CIS) observations
Lundin, R.; Balogh, A.; Dandouras, I. +10 more
On 3 December 2001 the Cluster spacecraft observed a long-lasting lobe reconnection event in the southern high-latitude dusk magnetopause (MP) tailward of the cusp, during a 4 hour interval of mainly northward interplanetary magnetic field (IMF) and of sub-Alfvénic magnetosheath flow. Almost all the MP encounters have accelerated flows (for which …
Energetic nitrogen ions within the inner magnetosphere of Saturn
Johnson, R. E.; Paranicas, C.; Sittler, E. C. +9 more
We investigate the importance of nitrogen ions within Saturn's magnetosphere and their contribution to the energetic charged particle population within Saturn's inner magnetosphere. This study is based on the Voyager observations of Saturn's magnetosphere and Cassini observations. The latter have shown that water group ions dominate both the plasm…
A global 2.5-dimensional three fluid solar wind model with alpha particles
Li, Xing; Li, Bo; Labrosse, Nicolas
A global 2.5-dimensional three fluid solar wind model is presented. Two ion species, namely protons and alpha particles, are heated by an empirical energy flux while electrons are heated by the classical heat flux and Coulomb coupling with ions. It is found that for a reasonable relative speed between alpha particles and protons at 1 AU to be achi…
Whistler-mode auroral hiss emissions observed near Saturn's B ring
Gurnett, D. A.; Hospodarsky, G. B.; Kurth, W. S. +2 more
An unusual whistler-mode emission, similar to terrestrial auroral hiss, was observed by the radio and plasma wave instrument on the Cassini spacecraft during the 1 July 2004 pass over the rings of Saturn. By using an electron density model that is consistent with measurements of the local electron plasma frequency, ray-tracing calculations have be…
Cluster encounter with an energetic electron beam during a substorm
Escoubet, C. P.; Thomsen, M. F.; Davies, J. A. +16 more
During a passage of the midtail plasma sheet, the Cluster 3 spacecraft made an unprecedented high-resolution measurement of a beam of electrons with energies up to 400 keV. The beam was only fully resolved by combining the energy range coverage of the Plasma Electron and Current Experiment and Research with Adaptive Particle Imaging Detector elect…