Search Publications
A self-consistent model of plasma and neutrals at Saturn: Neutral cloud morphology
Jurac, S.; Richardson, J. D.
We present a model of the plasma and neutral environment that treats plasma and neutrals self-consistently, using Voyager plasma and ultraviolet H observations and Hubble Space Telescope OH measurements as constraints. The neutral distributions are determined with a Monte Carlo model, and the plasma distributions are determined with a diffusive tr…
Variable morphology of Saturn's southern ultraviolet aurora
Clarke, J. T.; Cowley, S. W. H.; Bunce, E. J. +2 more
The Space Telescope Imaging Spectrograph camera on board Hubble Space Telescope obtained 68 FUV images of Saturn's southern auroral emission between 8 and 30 January 2004, during Cassini's approach to Saturn's magnetosphere. The HST observations took place in four different solar wind regimes with a low-field rarefaction region from 8 to 16 Januar…
Open flux estimates in Saturn's magnetosphere during the January 2004 Cassini-HST campaign, and implications for reconnection rates
Milan, S. E.; Badman, S. V.; Clarke, J. T. +4 more
During 8-30 January 2004, a sequence of 68 UV images of Saturn's southern aurora was obtained by the Hubble Space Telescope (HST), coordinated for the first time with measurements of the upstream interplanetary conditions made by the Cassini spacecraft. Using the poleward edge of the observed aurora as a proxy for the open-closed field line bounda…
Radial variations in the Io plasma torus during the Cassini era
Delamere, P. A.; Bagenal, F.; Steffl, A.
A radial scan through the midnight sector of the Io plasma torus was made by the Cassini Ultraviolet Imaging Spectrograph on 14 January 2001, shortly after closest approach to Jupiter. From these data, Steffl et al. (2004a) derived electron temperature, plasma composition (ion mixing ratios), and electron column density as a function of radius fro…
Cluster observations of traveling compression regions in the near-tail
Balogh, A.; Glassmeier, K. -H.; Owen, C. J. +6 more
Examination of Cluster measurements has revealed the presence of traveling compression regions (TCRs) in the lobes of the Earth's magnetotail at X ∼ -11-19 RE. These TCRs strongly resemble those observed in the more distant tail, but their mean duration is only ∼35 s as compared with ∼160 s for the TCRs in the distant tail. Furthermore,…
Characteristics of the magnetosheath electron boundary layer under northward interplanetary magnetic field: Implications for high-latitude reconnection
Balogh, A.; Thomsen, M. F.; Lavraud, B. +7 more
We analyze Cluster data to explore the statistical properties of the magnetosheath electron boundary layer, observed outside the high-latitude dayside magnetopause, under northward interplanetary magnetic field (IMF). We investigate the dependence of the presence and directionality of heated magnetosheath electrons in this layer on the geomagnetic…
Fast coronal mass ejection environments and the production of solar energetic particle events
Vourlidas, A.; Kahler, S. W.
The search continues for coronal environmental factors that determine whether a fast coronal mass ejection (CME) results in a solar energetic particle (SEP) event at 1 AU. From a plot of peak 20 MeV SEP intensities versus associated CME speeds we select for comparison two groups of fast, wide, western hemisphere CMEs observed with the LASCO corona…
Quasi-monochromatic ULF foreshock waves as observed by the four-spacecraft Cluster mission: 1. Statistical properties
Balogh, A.; Dandouras, I.; Eastwood, J. P. +2 more
Cluster data are used to study the statistics of a particular type of foreshock wave: quasi-monochromatic ultra-low-frequency (ULF) waves with characteristic periods of 30 s in the spacecraft frame. On the basis of a large set of foreshock observations made in 2001 with spacecraft separations ∼600 km, the intrinsic properties of the waves are foun…
How good is the relationship of solar and interplanetary plasma parameters with geomagnetic storms?
Kane, R. P.
Since the work of Snyder et al. (1963), who showed a possible link between interplanetary solar wind speed V and geomagnetic index Kp, such a relationship has been examined by many workers and found to be rather loose. In the present communication this relationship is rechecked for all data during 1973-2003. It was noted that moderate or strong ge…
Forecast evaluation of the coronal mass ejection (CME) geoeffectiveness using halo CMEs from 1997 to 2003
Cho, K. -S.; Kim, Y. -H.; Moon, Y. -J. +5 more
In this study we have made a forecast evaluation of geoeffective coronal mass ejections (CMEs) by using frontside halo CMEs and the magnetospheric ring current index, Dst. This is the first time, to our knowledge, that an attempt has been made to construct contingency tables depending on the geoeffectiveness criteria as well as to estimate the pro…