Search Publications
Non-self-similar scaling of plasma sheet and solar wind probability distribution functions of magnetic field fluctuations
Balogh, A.; Khurana, K. K.; Kistler, L. M. +5 more
Solar wind magnetometer and plasma data and magnetometer data acquired by Cluster in the magnetospheric plasma sheet are employed to construct probability distribution functions (PDFs) of magnetic field fluctuations over various temporal and spatial scales. This technique, often used in analysis of laboratory plasmas, is used to look for intermitt…
Statistical characteristics of hydrogen and oxygen ENA emission from the storm-time ring current
Mitchell, D. G.; Roelof, E. C.; Brandt, P. C. +2 more
The present study statistically examines energetic neutral atom (ENA) emission from the storm-time inner magnetosphere using measurements from the IMAGE/HENA instrument. It is found that the total image-integrated ENA energy flux is well correlated (∣c.c.∣ ∼ 0.7) with the Sym-H index. However, the increase is not linear but exponential with ∣Sym-H…
Solar wind speed within 20 RS of the Sun estimated from limb coronal mass ejections
Gopalswamy, Nat; Yashiro, Seiji; Nakagawa, Tomoko
An estimation of the solar wind speed in the vicinity of the Sun is carried out using the initial speed and acceleration of coronal mass ejections (CMEs) that appeared close to the solar limb. A linear relationship was found between the initial acceleration and the speed of the limb CMEs. It appears that a dragging force is acting on the CMEs, dep…
Instabilities driven by ion shell distributions observed by Cluster in the midaltitude plasma sheet boundary layer
Fazakerley, A. N.; Marchaudon, A.; Cornilleau-Wehrlin, N. +5 more
Cluster observations in the near-Earth plasma sheet boundary layer (PSBL) region have shown the presence of ion shell distributions related to velocity-dispersed ion structures (VDIS) coincident with electrostatic emissions. We have examined ion shell instabilities in the presence of a cold ion and electron background using linear theory and parti…
Small-scale solitary wave pulses observed by the Ulysses magnetic field experiment
Balogh, A.; Horbury, T. S.; Rees, A.
We present here a new class of isolated structure observed in interplanetary space. Events in this class consist of short-duration increases in the magnetic field magnitude and an associated rotation in the magnetic field direction, with a duration of the order of 30 s. After surveying the entire 14-year high-resolution (1 vector sample per 1 or 2…
Interpreting multipoint observations of substructure at the quasi-perpendicular bow shock: Simulations
Burgess, D.
Two-dimensional hybrid simulations of high Mach number quasi-perpendicular collisionless shocks, as relevant to the Earth's bow shock, show strong fluctuations of density and magnetic field within the average shock profile. In particular, there are rapid variations moving across the shock surface, in terms of local changes in its position and the …
Rapidly moving sources of upper band ELF/VLF chorus near the magnetic equator
Pickett, J. S.; Inan, U. S.; Platino, M. +2 more
Multiple simultaneous wideband (Gurnett et al., 2001) measurements on the Cluster spacecraft of upper band chorus emissions near the magnetic equator (at magnetic latitudes between -20° and 10° and L shells ranging between L = 4 and L = 5) are used to deduce the properties of the compact source regions of ELF/VLF chorus emissions. The frequency di…
On the behavior of O+5 in coronal holes: Importance of sunward propagating waves
Hollweg, Joseph V.
The high thermal anisotropy of O+5 in coronal holes, as observed by the Ultraviolet Coronagraph Spectrometer (UVCS) on the Solar and Heliospheric Observatory (SOHO), suggests that these ions are being heated by the cyclotron resonance. The observations indicate that the O+5 temperature steadily increases from r ≈ 1.5 rS<…
Electrodynamics of a split-transpolar aurora
RèMe, H.; Lester, M.; Dunlop, M. W. +6 more
We report new results on the relation between drift velocity shear, average inverted V energy, and the separation of bifurcated high-latitude Sun-aligned polar arcs within a global transpolar auroral arc system. The two parallel arcs appeared at the location of converging -v × B electric field of two sunward flow channels that were separated by an…
Striated drifting auroral kilometric radiation bursts: Possible stimulation by upward traveling EMIC waves
Santolik, O.; Menietti, J. D.; Mutel, R. L. +3 more
We investigate waves observed by the Cluster wideband instrument (WBD) during an orbital conjunction with the Polar spacecraft. During this perigee pass, Polar was at the upper extent of the auroral kilometric radiation (AKR) source region in the Southern Hemisphere nightside auroral region. Cluster was located at higher altitude above this region…