Search Publications
Self-Reformation of the Quasi-Perpendicular Shock: CLUSTER Observations
Dandouras, I.; Génot, V.; Lembège, B. +5 more
Among several mechanisms issued from simulation and theoretical studies proposed to account for the nonstationarity of quasi-perpendicular supercritical shocks, one process-the so-called self-reformation-driven by the accumulation of reflected ions in the foot has been intensively analyzed with simulations. Present results based on experimental CL…
Whistler Waves Driven by Anisotropic Strahl Velocity Distributions: Cluster Observations
Gurgiolo, C.; Goldstein, M. L.; Nieves-Chinchilla, T. +2 more
Observed properties of the strahl using high resolution 3D electron velocity distribution data obtained from the Cluster/PEACE experiment are used to investigate its linear stability. An automated method to isolate the strahl is used to allow its moments to be computed independent of the solar wind core+halo. Results show that the strahl can have …
Solar wind turbulent spectrum from MHD to electron scales
Saur, J.; Alexandrova, O.; Schwartz, S. J. +5 more
Turbulent spectra of magnetic fluctuations in the free solar wind are studied from MHD to electron scales using Cluster observations. We discuss the problem of the instrumental noise and its influence on the measurements at the electron scales. We confirm the presence of a curvature of the spectrum ~expkρe over the broad frequency range…
Analysis of waves surrounding foreshock cavitons
Kajdič, Primož; Russell, Christopher T.; Blanco-Cano, Xochitl +1 more
Cavitons have been recently discovered in the Earth's foreshock. Foreshock cavitons have first been predicted by global hybrid simulations and later structures with similar properties were discovered in observational data from the Cluster mission. Cavitons are observed as simultaneous depressions of the magnitude of the magnetic field and plasma d…
Kelvin-Helmholtz Multi-Spacecraft Studies at the Earth's Magnetopause Boundaries
Farrugia, C. J.; Fazakerley, A. N.; Owen, C. J. +2 more
The Kelvin-Helmholtz (KH) instability can operate in various situations in the solar wind, but at the boundaries of planetary obstacles, for example the Earth's magnetopause, it is most amenable to investigation. Reliable estimates of wave characteristics are essential for comparison with theoretical and numerical models and for understanding the …
Structures and Intermittency in Small Scales Solar Wind Turbulence
Sahraoui, Fouad; Goldstein, Melvyn
Several observations in space plasmas have reported the presence of coherent structures at different plasma scales. Structure formation is believed to result from nonlinear interactions between the plasma modes, which depend strongly on their phase synchronization. Despite this important role of the phases in turbulence, very limited work has been…
Fractal dissipation of small-scale magnetic fluctuations in solar wind turbulence as seen by CLUSTER
Khotyaintsev, Y.; Sahraoui, F.; Chapman, S. +2 more
A robust multiscale analysis of high-frequency magnetic field measurements from the Cluster spacecraft is presented using complimentary measurements from the magnetometer and search-coil instruments; in a stationary interval of fast ambient solar wind. We show a surprising and novel result: that for time-scales smaller than the ion-gyro period the…
Heliospheric Current Sheet Distortions from Adjacent Outflowing Transients: Multi-spacecraft Observations
Lavraud, B.; Fazakerley, A. N.; Owen, C. J. +2 more
The heliospheric current sheet (HCS) is a permanent solar wind feature, with well predicted Earth passages, but it can be structured and its main orientation can be highly distorted. We report new observations from 2 spacecraft in the solar wind (supported by observations from 3 spacecraft in the nightside magnetosheath), showing an evolution acro…
Waves at the plasma frequency inside magnetic holes: STEREO and Cluster observations
Bale, S. D.; Goetz, K.; Soucek, J. +2 more
Magnetic isolated large amplitude depressions in the interplanetary magnetic field are commonly observed in the solar wind. Some of these magnetic structures are accompanied by bursts of electrostatic waves close to electron plasma frequency. Combining STEREO/WAVES and IMPACT data we are able to accurately localize the waves emission. We show that…
Observation of Langmuir waves in the solar wind and the role of the antenna effective length
Pickett, J. S.; Souček, J.; Santolík, O. +3 more
Recently it was shown that in resonance regions the antenna effective length can exceed its physical length. Here we show that this happens in reception of Langmuir waves in a streaming solar wind and we discuss the relevant observations of narrow band emissions observed by CLUSTER II.