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Solar wind from the coronal hole boundaries
Geiss, J.; McComas, D. J.; Schwadron, N. A. +3 more
Recent studies using in situ observations established that the interface between fast and slow wind in interplanetary space has two distinct parts: a smoothly varying boundary layer flow that flanks fast wind from coronal holes and a sharper plasma discontinuity between intermediate and slow solar wind. Other studies using in situ observations and…
Dynamic Harris current sheet thickness from Cluster current density and plasma measurements
Balogh, A.; Khurana, K. K.; Kistler, L. M. +5 more
We use the first accurate measurements of current densities in the plasma sheet to calculate the half-thickness and position of the current sheet as a function of time. Our technique assumes a Harris current sheet model, which is parameterized by lobe magnetic field B0, current sheet half-thickness h, and current sheet position z0<…
Interplanetary conditions and magnetospheric dynamics during the Cassini orbit insertion fly-through of Saturn's magnetosphere
Jackman, C. M.; Kurth, W. S.; Cecconi, B. +5 more
The primary purpose of this paper is to discuss the interplanetary conditions that prevailed during the Saturn orbit insertion (SOI) fly-through of Saturn's magnetosphere by the Cassini spacecraft in June-July 2004 and the consequent magnetospheric dynamics. We begin by examining concurrent interplanetary magnetic field (IMF) and Saturn kilometric…
On the generation of enhanced sunward convection and transpolar aurora in the high-latitude ionosphere by magnetic merging
Balogh, A.; RèMe, H.; Dunlop, M. W. +11 more
The IMAGE Wideband Imaging Camera (WIC) instrument observed the duskside development of an oval-aligned transpolar auroral arc (TPA) in the Northern Hemisphere (NH) on 16 December 2001 during strong IMF ∣B∣ ∼ 18 nT and a generally steady ∼56° clock angle (positive IMF By and Bz). Observational evidence suggests that the daysi…
Quasi-monochromatic ULF foreshock waves as observed by the four-spacecraft Cluster mission: 2. Oblique propagation
Balogh, A.; Dandouras, I.; Eastwood, J. P. +2 more
This paper presents the results of a statistical investigation into the nature of oblique wave propagation in the foreshock. Observations have shown that foreshock ULF waves tend to propagate obliquely to the background magnetic field. This is in contrast to theoretical work, which predicts that the growth rate of the mechanism responsible for the…
Size and shape of ULF waves in the terrestrial foreshock
Balogh, A.; Dandouras, I.; Horbury, T. S. +3 more
Using simultaneous four spacecraft data, estimates of the size and shape of ULF waves in the terrestrial foreshock are presented. Estimates of the size of the waves in different directions are obtained by calculating the spatial autocorrelation function of the magnetic field in the wave frame using cross-correlations of magnetic field measurements…
From the Sun to the outer heliosphere: Modeling and analyses of the interplanetary propagation of the October/November (Halloween) 2003 solar events
Sun, Wei; Intriligator, Devrie S.; Dryer, Murray +3 more
We use the space weather validated 3-D HAFv2 model to help us study the interplanetary propagation of the October/November 2003 solar eruptions from the Sun to >90 AU and over a wide range of heliolongitudes and heliolatitudes. The HAFv2 model predictions at ACE (1 AU), Ulysses (5.23 AU), Cassini (8.67 AU), Voyager 2 (73 AU), and Voyager 1 (93 …
Extreme solar-terrestrial events of October 2003: High-latitude and Cluster observations of the large geomagnetic disturbances on 30 October
Buchert, S.; Amm, O.; Rosenqvist, L. +3 more
The extremely large solar eruption on 28 October 2003 caused an intense geomagnetic storm at Earth. A second solar eruption on 29 October resulted in a reintensification of the storm about a day later. Similarities and differences between these two events in terms of solar eruption, solar wind driver, and their resulting effect on the near-Earth e…
Stagnant exterior cusp region as viewed by energetic electrons and ions: A statistical study using Cluster Research with Adaptive Particle Imaging Detectors (RAPID) data
Zhang, H.; Zong, Q. -G.; Daly, P. W. +1 more
We present statistical results based on the data set obtained by Cluster when these spacecraft were in the dayside cusp and magnetopause. Forty clearest stagnant exterior cusp (SEC) events have been selected from ∼150 cusp crossings from 1 January to 30 April 2001 and from 1 March to 30 April 2002. The identification of the SECs was made on the ba…
Titan interaction with Saturn's magnetosphere: Voyager 1 results revisited
Johnson, R. E.; Hartle, R. E.; Sittler, E. C. +3 more
We investigate the details of Titan's interaction with Saturn's magnetosphere, which includes formation and location of an ionopause, mass loading via ion pickup, and the effects of finite gyroradii. We present new interpretations of the Voyager 1 plasma instrument measurements not addressed by Hartle et al. (1982). Pickup ions H+ and H…