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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…
Anisotropy of the Taylor scale and the correlation scale in plasma sheet magnetic field fluctuations as a function of auroral electrojet activity
El-Alaoui, M.; Dasso, S.; Matthaeus, W. H. +2 more
Magnetic field data from the Cluster spacecraft in the magnetospheric plasma sheet are employed to determine the correlation scale and the magnetic Taylor microscale from simultaneous multiple-point measurements for multiple intervals over a range of mean magnetic field directions for three different levels of geomagnetic activity. We have determi…
Moderate geomagnetic storm (21-22 January 2005) triggered by an outstanding coronal mass ejection viewed via energetic neutral atoms
Barabash, Stas; McKenna-Lawlor, Susan; Dandouras, Iannis +7 more
An outstanding flare on 20 January 2005 was accompanied by a coronal mass ejection which arrived at the magnetopause at ∼1712 UT, 21 January, and produced a strong compression-pressure pulse. Enhanced magnetospheric activity was stimulated. The associated development between <1800 UT and >02.19 UT on 21-22 January, 2005 of a ring current dis…
Whistler propagation and modulation in the presence of nonlinear Alfvén waves
Goldstein, M. L.; Sharma, R. P.; Dwivedi, Navin Kumar +1 more
This paper presents the modulation of whistler waves due to linear interactions between a weak whistler signal and a pump kinetic Alfvén wave (KAW) in intermediate-β(me/mi ≪ β ≪ 1) plasmas (where β is the ratio of the ion sound speed to the Alfvén speed). As a consequence of ponderomotive nonlinearity, the pump KAW becomes fi…
Venusian bow shock as seen by the ASPERA-4 ion instrument on Venus Express
Coates, A. J.; Kallio, E.; Schmidt, W. +40 more
The Analyzer of Space Plasmas and Energetic Atoms (ASPERA-4) instrument on Venus Express is used to determine bow shock position at Venus using ion data alone, using data recorded during a solar minimum from the Ion Mass Analyzer (IMA) which is part of the ASPERA-4 package. Previous models constructed from solar minimum data using Venus Express, P…