Search Publications
Magnetic complexity in eruptive solar active regions and associated eruption parameters
Georgoulis, Manolis K.
Using an efficient magnetic complexity index in the active-region solar photosphere, we quantify the preflare strength of the photospheric magnetic polarity inversion lines in 23 eruptive active regions with flare/CME/ICME events tracked all the way from the Sun to the Earth. We find that active regions with more intense polarity inversion lines h…
Cassini encounters with hot flow anomaly-like phenomena at Saturn's bow shock
Coates, A. J.; Dougherty, M. K.; Thomsen, M. F. +7 more
The first observations of the kronian equivalent of hot flow anomalies (HFAs) are presented. Using magnetic field and plasma data we discuss two events that were observed upstream of Saturn's bow shock during the first two orbits of the Cassini spacecraft. We suggest that these events result from the interaction between interplanetary current shee…
Understanding the global evolution of Saturn's ring current
Krimigis, S. M.; Mitchell, D. G.; Carbary, J. F. +3 more
An explanation for the morphology and evolution of the ring current in Saturn's magnetosphere is provided. We use global Energetic Neutral Atom (ENA) images of the 20-140 keV proton distribution obtained by the Ion and Neutral Camera (INCA) on board the Cassini spacecraft. A case where the ring current displays an exceptionally clear spiral shape …
A non-hydrostatic Rhea
Mackenzie, R. A.; Iess, L.; Tortora, P. +1 more
Radiometric data obtained during Cassini's close flyby of Rhea, on 26 November 2005, has been subject to several published analyses aiming to determine the satellite's mass and quadrupole gravity moments. Combining aspects of two of these analyses we present our best, unbiased estimates of the gravity field parameters and point out how the constra…
Spectral variability of the Martian high latitude surfaces
Bibring, J. -P.; Gondet, B.; Langevin, Y. +3 more
We report the surface distributions of some minerals in the high latitude (>50°) regions of Mars using the OMEGA/MEx observations in the near-infrared wavelength domains (1-2.5 µm). Mafic minerals (pyroxene and olivine) are observed in the low albedo terrains. The identification of these minerals is consistent with the presence of volcani…
Retreat and reformation of X-line during quasi-continuous tailward-of-the-cusp reconnection under northward IMF
Khotyaintsev, Y.; Vaivads, A.; Hasegawa, H. +6 more
We present observations on 19-20 November 2006 by the Cluster spacecraft that were skimming the high-latitude dusk-flank magnetopause, which are consistent with more than one reconnection X-line present on the tailward side of the cusp under northward IMF. Evidence of quasi-continuous reconnection over 16 hours exists in the form of Alfvénic accel…
Angular beaming model of Jupiter's decametric radio emissions based on Cassini RPWS data analysis
Imai, Masafumi; Imai, Kazumasa; Higgins, Charles A. +1 more
Observations of the low frequency part of Jupiter decameter wavelength (DAM) emissions were made using the Cassini radio and plasma wave science (RPWS) instrument. We have analyzed non-Io-DAM occurrence dependence from 4 MHz to 16 MHz based on the System III central meridian longitude (CML) of the Cassini spacecraft and calculated the occurrence p…
Multi-point observations of the inner boundary of the plasma sheet during geomagnetic disturbances
Dandouras, I.; Glassmeier, K. -H.; Nakamura, R. +6 more
We report on the THEMIS and Double Star TC-1 observations at the geocentric distances of 3 < R < 8 R E during substorms on March 23, 2007. THEMIS crossed the inner boundary of the equatorial dusk-side plasma in the string-of-pearls configuration, allowing the dynamics of particle populations to be traced within time ranges from h…
Mass unloading along the inner edge of the Enceladus plasma torus
Gurnett, D. A.; Persoon, A. M.; Kurth, W. S. +4 more
A major discovery made by the Cassini spacecraft at Saturn was the substantial mass ejection from the south pole of Enceladus. Previous studies show that this ejected gas can become ionized and subsequently load mass onto the connecting magnetic field lines near the moon. Radial diffusion then allows the mass-loaded field lines to move outward to …
Small-scale, localized electromagnetic waves observed by Cluster: Result of magnetosphere-ionosphere interactions
Karlsson, T.; Streltsov, A. V.
We present results from a numerical study of small-scale, localized electromagnetic structures measured by the Cluster satellites on May 19, 2002, in the nightside magnetosphere. A comprehensive analysis of these structures by Karlsson et al. (2004), Johansson et al. (2004) and Marklund et al. (2004) demonstrates that they can be interpreted as tw…