Search Publications
Influence of Saturnian moons on Saturn kilometric radiation
Gurnett, D. A.; Hospodarsky, G. B.; Kurth, W. S. +4 more
Similar to past studies at Jupiter, we conduct an investigation of possible associations of radio emission occurrence probability with the orbital phases of Saturnian moons. We use a new definition of the Saturn longitude system (SLS) based on the results of Kurth et al. (2007). This paper presents results of our findings to date, sampling a large…
Constraining and validating the Oct/Nov 2003 X-class EUV flare enhancements with observations of FUV dayglow and E-region electron densities
Meier, R. R.; Lean, J. L.; Paxton, L. J. +10 more
Near peak activity of two X-class solar flares, on 28 October and 4 November 2003, the Thermosphere Ionosphere Mesosphere Energetics and Dynamics (TIMED)/Solar EUV Experiment (SEE) instrument recorded order of magnitude increases in solar EUV irradiance, the TIMED/Global Ultraviolet Imager (GUVI) observed simultaneous increases in upper atmosphere…
A comparison of Cluster magnetic data with the Tsyganenko 2001 model
Davies, J. A.; Woodfield, E. E.; Dunlop, M. W. +2 more
As part of an investigation of the magnetic effects of external currents in the magnetosphere, we have compared two years of perigee Cluster data to the Tsyganenko 2001 (T01) field model. Cluster data are not included in the T01 database and therefore can be used to independently verify the model. The model performs very well in a global sense; ne…
Spectra of polar heliospheric fields and implications for field structure
Giacalone, Joe; Jokipii, J. R.; Goldstein, Melvyn L. +2 more
The predictions of the ``Fisk'' model for a peak at the equatorial solar rotation frequency in the spectrum of the latitudinal component of the heliospheric magnetic field were found to give values significantly larger than those observed. The observed values were statistically the same as observed in the ecliptic and were consistent with random f…
Radio tracking of the interplanetary coronal mass ejection driven shock crossed by Ulysses on 10 May 2001
MacDowall, R. J.; Hoang, S.; Lacombe, C. +1 more
We report on the detection of type II radio emission which was observed for more than a day prior to the arrival of an interplanetary shock at Ulysses. We use local spectral emission peaks, computerized from time-averaged intensity spectra of the type II burst, to track the associated emitting shock. In the spectrogram plotted as a function of tim…
Spectral features of SKR observed by Cassini/RPWS: Frequency bandwidth, flux density and polarization
Lecacheux, Alain; Boudjada, Mohammed Y.; Galopeau, Patrick H. M.
We report on an analysis about the spectral shape of the Saturnian kilometric radiation (SKR) recorded by the RPWS/HFR experiment onboard the Cassini spacecraft. The SKR envelope is found to be very variable in timescales covering a large range, from hours to days. Despite this change, we proceed to a classification of the shape in the frequency r…
Simultaneous observations of magnetotail reconnection and bright X-ray aurora on 2 October 2002
RèMe, H.; Lucek, E. A.; Mouikis, C. +9 more
We present simultaneous Cluster and Polar X-ray and UVI observations on 2 October 2002, when Cluster observed a magnetic reconnection diffusion region at Xgse = -16.6 Re. At the same time a bright auroral feature appeared at the footpoint of the magnetic field line connecting the ionosphere and the diffusion region. However, we found that the elec…
Low-frequency waves in the foreshock of Saturn: First results from Cassini
Dougherty, M. K.; Hospodarsky, G. B.; Thomsen, M. +4 more
We present the first characterization of low-frequency upstream waves associated with Saturn's foreshock from observations by the Cassini spacecraft. A classification based on their frequency in the spacecraft frame (s/c) yields two groups: (1) a large majority of waves with frequencies below the local proton cyclotron frequency ΩH+ and…
Energetic particles during the first and third Ulysses southern high-latitude excursions: Probing global corotating interaction region structure beyond 5 AU
Lario, D.; Roelof, E. C.
We analyze energetic particle observations during the first and third ascents of Ulysses to the southern regions of the heliosphere. The first high-latitude excursion occurred in the declining phase of solar cycle 22, while the third occurred in a later phase of solar cycle 23. In contrast to the long-lived and well-defined ~26-day recurrent inten…
Ion thermalization and wave excitation downstream of Earth's bow shock: A theory for Cluster observations of He2+ acceleration
Lee, Martin A.; Kucharek, Harald; Liu, Yong C. -M. +1 more
It has been well documented that the plasma immediately downstream of Earth's quasi-perpendicular bow shock, which consists of reflected protons and directly transmitted ions with large temperature anisotropies (T⊥/Tz), is unstable to the excitation of ion cyclotron waves. These waves in turn scatter the protons and ions to m…