Search Publications
Cluster electric current density measurements within a magnetic flux rope in the plasma sheet
Balogh, A.; Owen, C. J.; Reme, H. +11 more
On August 22, 2001 all 4 Cluster spacecraft nearly simultaneously penetrated a magnetic flux rope in the tail. The flux rope encounter took place in the central plasma sheet, βi ~ 1-2, near the leading edge of a bursty bulk flow. The ``time-of-flight'' of the flux rope across the 4 spacecraft yielded Vx ~ 700 km/s and a diame…
Properties of high heliolatitude solar energetic particle events and constraints on models of acceleration and propagation
Balogh, A.; Krucker, S.; Dalla, S. +10 more
We analyse 9 large solar energetic particle (SEP) events detected by the Ulysses spacecraft at high heliolatitudes during the recent solar maximum polar passes. Properties of time intensity profiles from the Ulysses/COSPIN instrument are compared with those measured by SOHO/COSTEP and Wind/3DP near Earth. We find that onset times and times to maxi…
Bashful ballerina: Southward shifted heliospheric current sheet
Mursula, K.; Hiltula, T.
It is known since long [Rosenberg and Coleman, 1969] that one of the two sectors of the interplanetary magnetic field (IMF) observed at the Earth's orbit dominates at high heliographic latitudes during solar minimum times, reflecting the poloidal structure of the global solar magnetic field at these times. Here we find that while this latitudinal …
A statistical study of CMEs associated with metric type II bursts
Gopalswamy, N.; Yashiro, S.; Lara, A. +2 more
We present a statistical study of the characteristics of CMEs which show temporal association with type II bursts in the metric domain but not in the decameter/hectometric (DH) domain. This study is based on a set of 80 metric (m) type II bursts associated with surface events in the solar western hemisphere. It was found that in general, the distr…
Simulation of energetic particle injections associated with a substorm on August 27, 2001
Baker, D. N.; Sarris, T. E.; Peterson, W. K. +2 more
Discrete injections of energetic electrons and ions and their subsequent drift echoes were observed shortly after 0410 UT on August 27, 2001 by three geosynchronous satellites which were arrayed on the dayside. The GOES-8 spacecraft at geosynchronous orbit near local midnight, the four-satellite CLUSTER constellation also near local midnight. Conc…
Properties of high-latitude CME-driven disturbances during Ulysses second northern polar passage
St. Cyr, O. C.; Reisenfeld, D. B.; Forsyth, R. J. +2 more
Ulysses observed five coronal mass ejections (CMEs) and their associated disturbances while the spacecraft was immersed in the polar coronal hole (CH) flow above 70° N in late 2001. Of these CMEs, two were very fast (>850 km s-1) driving strong shocks in the wind ahead, and two others were over-expanding. The two fast CMEs were obser…
Kink mode oscillation of the current sheet
Balogh, A.; Zhang, T. L.; Glassmeier, K. -H. +6 more
Oscillations of the current sheet observed by the Cluster spacecraft are investigated, using the special ability of Cluster to separate between spatial and temporal variations. We find that before substorm onset, a thin current sheet moves with a velocity of 10 km/s mainly in the vertical direction; after substorm onset the current sheet thickens …
Dispersion analysis of ULF waves in the foreshock using cluster data and the wave telescope technique
Dandouras, I.; Glassmeier, K. -H.; Rème, H. +6 more
Cluster provides us with a unique possibility to study ULF waves. We analyze ULF wave activity in the near-Earth upstream solar wind. Using Cluster as a wave telescope we investigate in detail wave propagation directions and wave numbers for various frequencies, obtaining, for the first time, three dimensional dispersion relations experimentally. …
Long-duration hectometric type III radio bursts and their association with solar energetic particle (SEP) events
MacDowall, R. J.; Bougeret, J. L.; Lara, A. +3 more
It has recently been suggested by Cane et al. [2002] that a class of type III solar radio bursts, called type III-l, is reliably associated with intense solar energetic particle (SEP) events. They proposed that the causative electrons for these bursts are accelerated in regions of reconnecting magnetic field in the wakes of coronal mass ejections …
Magnetic mirror structures observed by Cluster in the magnetosheath
Glassmeier, K. -H.; Treumann, R.; Constantinescu, O. D. +1 more
We present a method for identification of magnetic mirror structures (MMS) in multi-point spacecraft measurements and for deriving their full 3D geometry. Multiple minima in magnetic field data are no longer regarded as separate MMS but as belonging to the same mirror structure. The approach is based on fitting a model magnetic field to measured d…