Search Publications
Observation of similar radio signatures at Saturn and Jupiter: Implications for the magnetospheric dynamics
Gurnett, D. A.; Persoon, A. M.; Hospodarsky, G. B. +13 more
We report on radio signatures observed at Saturn by the Cassini RPWS experiment which are strikingly similar to the Jovian ``energetic events'' observed by Galileo. They consist of sudden intensifications of the auroral radio emission (SKR) followed by the detection of a periodic narrowband radiation which most likely originates from Saturn's plas…
Absorption of MARSIS radar signals: Solar energetic particles and the daytime ionosphere
Espley, Jared R.; Plaut, Jeffrey J.; Farrell, William M. +5 more
We present observations from the subsurface sounding mode of the MARSIS instrument onboard Mars Express that imply radar wave absorption because of increased amounts of ionization in the upper Martian atmosphere during the fall of 2005. On at least two occasions these radar disruptions lasted for several days and we find that these periods are cor…
Evidence for spiral pattern in Saturn's magnetosphere using the new SKR longitudes
Krupp, N.; Krimigis, S. M.; Mitchell, D. G. +1 more
The periodicities in electrons observed in Saturn's magnetosphere are examined using the new longitude system based on a drifting signal of Saturn kilometric radiation (SKR). When averaged into longitude and range bins over 50-day time periods, 28-48 keV electron intensities clearly evidence patterns that peak at successively increasing longitudes…
Periodic microstructure in Saturn's rings A and B
French, Richard G.; Tyler, G. Leonard; Marouf, Essam A. +2 more
Diffraction of coherent radio waves transmitted by the Cassini spacecraft at 0.94- and 3.6-cm wavelengths indicates the presence of fine-scale structure in Saturn's rings A and B, characterized by a periodic radial variation in optical depth. Interpretation of the observed spectral signature in terms of a simple diffraction grating model yields es…
Neutral cloud interaction with Saturn's main rings
Jurac, S.; Richardson, J. D.
The dense water cloud just outward of Saturn's main rings could strongly influence the surface composition of main ring constituents. Cassini pictures display brightening toward the outer edges of the main rings, suggesting that the outer edges have more icy material. We show that this enhanced brightening might not be a ring evolutionary feature,…
On Martian nitrogen dayglow emission observed by SPICAM UV spectrograph/Mars Express
Leblanc, F.; Bertaux, J. L.; Chaufray, J. Y.
SPICAM UV spectrograph on board Mars Express has reported, for the first time, the identification of the N2 VK (0,5) and (0,6) band emissions in the Martian dayglow. The derived exospheric temperature of the N2 species in the upper Martian atmosphere is equal to 190 +/- 51 K for areocentric longitudes between 100° and 171° an…
Flow burst-induced Kelvin-Helmholtz waves in the terrestrial magnetotail
Zhang, T. L.; Glassmeier, K. -H.; Lucek, E. +7 more
The Kelvin-Helmholtz instability (KHI) on the boundary of a flow channel in the Earth's plasma sheet is investigated using Cluster and Double Star TC1 data. It is shown that when Cluster moves into the flow channel the magnetometer measures strong oscillations of the magnetic field, that increase as the spacecraft move further into the flow channe…
Formation of VLF chorus frequency spectrum: Cluster data and comparison with the backward wave oscillator model
Pickett, J. S.; Trakhtengerts, V. Y.; Demekhov, A. G. +7 more
The dependence of the frequency spectrum of individual chorus elements on the position of the observation point in and near the generation region is analyzed using recent Cluster data obtained on two different geomagnetically active days. The source of night-side chorus is localized using multicomponent measurements of the wave electric and magnet…
TC-1 observations of flux pileup and dipolarization-associated expansion in the near-Earth magnetotail during substorms
Escoubet, C. P.; Dandouras, I.; Zhang, H. +16 more
Fifty-three substorms measured by Double Star/TC-1 in the near-Earth magnetotail from July to October, 2004 are studied. The main features of these events are: (a) Magnetic flux pileup characterized by continuous enhancement of B z is observed, which starts almost simultaneously with aurora breakup within 1-3 minutes, indicating that …
Observation of repeated intense near-Earth reconnection on closed field lines with Cluster, Double Star, and other spacecraft
Sauvaud, J. -A.; Zhang, T. L.; Glassmeier, K. -H. +14 more
We report strong repeated magnetic reconnection pulses that occurred deep inside closed plasma sheet flux tubes at r ≤ 14Re. They have been observed with a fortuitous spacecraft constellation during three consecutive turbulent magnetic dipolarizations, accompanied by localized auroral brightenings near the equatorward edge of a wide auroral oval. …