Search Publications
Magnetospheric feedback in solar wind energy transfer
Janhunen, P.; Lester, M.; Milan, S. E. +4 more
The solar wind kinetic energy fueling all dynamical processes within the near-Earth space is extracted in a dynamo process at the magnetopause. This direct energy transfer from the solar wind into the magnetosphere depends on the orientation of the interplanetary magnetic field (IMF) as well as other solar wind parameters, such as the IMF magnitud…
Statistical study of low-frequency magnetic field fluctuations near Venus under the different interplanetary magnetic field orientations
Zhang, T. L.; Wang, C.; Baumjohann, W. +4 more
The magnetic field fluctuations near Venus are investigated in the frequency range 0.03-0.3 Hz on the basis of the measurements observed by Venus Express from April 2006 to December 2008. The data are sorted by the angle between interplanetary magnetic field (IMF) and solar wind flow. The spatial distributions of fluctuation properties under the d…
Interaction of Saturn's magnetosphere and its moons: 3. Time variation of the Enceladus plume
Russell, C. T.; Khurana, K. K.; Gombosi, T. I. +3 more
The major momentum-loading source in Saturn's magnetosphere, Enceladus, has been studied with seven Cassini flybys between 2005 and 2008. In this paper, we first use parameter tests with our 3-D magnetohydrodynamic simulation to demonstrate and determine the sensitivity of the interaction to both electron impact rates and charge-exchange rates. We…
Waves at the electron plasma frequency associated with solar wind magnetic holes: STEREO/Cluster observations
Henri, P.; Soucek, J.; Mangeney, A. +1 more
Magnetic depressions are common structures of the interplanetary medium. These magnetic holes can be just isolated dips of the amplitude of the field or they can be associated with discontinuities in the field orientation (tangential or rotational). Electrostatic waves at the plasma frequency (Langmuir waves) are often observed in these magnetic s…
Characteristics of Langmuir electric field waveforms and power spectra exhibiting nonlinear behavior in Earth's foreshock
Gurnett, D. A.; Pickett, J. S.; Lucek, E. +6 more
Langmuir wave characteristics in the Earth's foreshock were examined to identify possible nonlinear wave behavior for two case studies with data from the Cluster Wideband Data Plasma Wave Receiver. The occurrence rates of four types of power spectra near the foreshock edge were determined: (1) spectra with power at the local plasma frequency f
Electrostatic field and ion temperature drop in thin current sheets: A theory
Donovan, E. F.; Liu, W. W.; Liang, J.
The observational evidence presented by Liang et al. (2009) showed that a neutral sheet-pointing electrostatic field frequently arises in the late growth-phase current sheet in the magnetotail. In this paper, we elaborate on the suggestion that this electric field is associated with the thinning of the current sheet to the ion scale at which the e…
Three-dimensional hybrid simulation of magnetosheath reconnection under northward and southward interplanetary magnetic field
Deng, X. H.; Wang, X. Y.; Pang, Y. +2 more
A three-dimensional (3-D) global hybrid simulation is carried out for the generation and structure of magnetic reconnection in the magnetosheath because of the interaction of an interplanetary tangential discontinuity (TD) with the bow shock and magnetosphere. Runs are performed for solar wind TDs possessing different polarization senses of magnet…
Comprehensive ground-based and in situ observations of substorm expansion phase onset
Zhang, T. L.; Fazakerley, A. N.; Volwerk, M. +8 more
In this paper, we present comprehensive ground-based and space-based in situ geosynchronous observations of a substorm expansion phase onset on 1 October 2005. The Double Star TC-2 and GOES-12 spacecraft were both located within the substorm current wedge during the substorm expansion phase onset, which occurred over the Canadian sector. We find t…
On the relationship between coronal heating, magnetic flux, and the density of the solar wind
McComas, D. J.; Schwadron, N. A.; Riley, Pete +3 more
The stark differences between the current solar minimum and the previous one offer a unique opportunity to develop new constraints on mechanisms for heating and acceleration of the solar wind. We have used a combination of numerical simulations and analysis of remote solar and in situ observations to infer that the coronal heating rate, H, scales …
Low-energy electrons in Saturn's inner magnetosphere and their role in interchange injections
Coates, A. J.; Young, D. T.; Burch, J. L. +2 more
Since the days of Pioneer 11 and the Voyager missions, electrons have shown an unexplained peak in the data at approximately 7.5 Saturn radii (RS). To investigate this peak, we examine near-equatorial electron energy flux data (±10°) from the Cassini Plasma Spectrometer Electron Spectrometer from 1 July 2004 through 10 August 2007. When…