Search Publications
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…
Quasi-periodic Fluctuations Detected in Mars Express Coronal Radio Sounding Observations
Pätzold, M.; Bird, M. K.; Tellmann, S. +5 more
Spectral analysis of the high-quality dual-frequency data obtained with the radio sounding experiment MaRS on the ESA spacecraft Mars Express has revealed a quasi-periodic component (QPC) at heliocentric distances from 4 to 10 solar radii. The QPC typically appears as a broad maximum in the temporal frequency fluctuation spectrum centered at a fre…
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…
Tracking Nonradial Motions and Azimuthal Expansions of Interplanetary CMEs with the Solar Mass Ejection Imager
Webb, David; Kahler, Stephen
The trajectories of interplanetary CMEs (ICMEs) are modified by their interactions with solar wind streams. These interactions can result in non-radial deflections of ICME trajectories and changes to their rates of azimuthal expansion. The Solar Mass Ejection Imager (SMEI), launched earlier in 2003 January, has provided heliospheric images of seve…
Compressive turbulent cascade and heating in the solar wind
Bruno, R.; Carbone, V.; Sorriso-Valvo, L. +2 more
A turbulent energy cascade has been recently identified in high-latitude solar wind data samples by using a Yaglom-like relation. However, analogous scaling law, suitably modified to take into account compressible fluctuations, has been observed in a much more extended fraction of the same data set recorded by the Ulysses spacecraft. Thus, it seem…
SOHO/UVCS Detection of Turbulence in a Coronal Mass Ejection
Antonucci, E.; D'Amicis, R.; Telloni, D.
The intensity of the H I Lyα line measured by the UltraViolet Coronagraph Spectrometer (UVCS) onboard the Solar and Heliospheric Observatory (SOHO) is used to investigate the density turbulence within the coronal mass ejection (CME) occurred on 2006 December 24, in the South polar coronal hole. In order to compare the spectral index inside the CME…
Study of Three ICMEs Events Registered by Ulysses in 2001
Dumitrache, Cristiana; Popescu, Nedelia A.
In-situ data measured by Ulysses-SWOOPS, SWICS and VHM instruments-are used for the study of magnetic field and solar wind plasma parameters for the year 2001, in an attempt of founding new ICMEs based on the combination of classical identification conditions, plasma dynamics signatures, and plasma composition signatures. Three new candidates are …
Coronal Fine Linear Rays: Are They Fast Streams From Active Regions?
Golub, Leon; Filippov, Boris; Lamy, Philippe +3 more
Eclipse observations of the W-L corona show linear rays above active regions at times of solar maximum. We show that these linear rays are also observed in the field-of-view of the C2-LASCO coronagraph, in perfect correspondence with the eclipse results. A selected prominent case taken from the 2001 eclipse observation in Angola is analysed with s…
High resolution measurements of magnetic field fluctuations associated with transitions in solar wind parameters
Perri, S.; Balogh, A.
Fluctuations in the solar wind parameters and in the heliospheric magnetic field have been studied extensively. The nature of fluctuations has been shown to depend on the origin of the solar wind. However, the regions of transition between the high-speed and the slow speed streams have not been investigated with high resolution. In this work we us…