Search Publications
Time-varying magnetospheric environment near Enceladus as seen by the Cassini magnetometer
Russell, C. T.; Dougherty, M. K.; Khurana, K. K. +3 more
In 2008, the Cassini spacecraft made four close Enceladus flybys along similar trajectories. During these flybys the magnetometer recorded the time-varying magnetic field associated with the plasma interaction with Enceladus and its plume. Close to Enceladus, the Cassini magnetometer observed 4% to 7% enhancement in the magnetic field magnitude, a…
The spectrum of a Saturn ring spoke from Cassini/VIMS
Brown, R. H.; Nicholson, P. D.; Bellucci, G. +7 more
On 2008, July, the Cassini/VIMS spectrometer detected spokes on the Saturn's B ring for the first time. These are the first measurements of the complete reflectance spectrum of the spokes in a wide spectral range (0.35-0.51 µm). Here we will focus on a single broad-shaped spoke, imaged by VIMS on July, 9. Radiative transfer modeling supports…
Widely different characteristics of oxygen and hydrogen ion escape from Venus
Kallio, E.; Janhunen, P.; Jarvinen, R. +2 more
We study the solar wind induced escape of O+ and H+ ions from Venus' atmosphere in the HYB-Venus hybrid simulation. Most of the previous Venus global plasma modelling studies have concentrated only on the O+ escape. According to the hybrid simulation, planetary O+ and H+ ions behave very diffe…
Oxygen energization by localized perpendicular electric fields at the cusp boundary
Waara, M.; Nilsson, H.; André, M. +3 more
We report Cluster observations of oxygen energization by several keV at the boundary between the high latitude cusp and lobe. A localized electric field at the cusp/lobe boundary is responsible for a significant part of the observed energization. Such electric fields can be related to the separatrix region of reconnection at the magnetopause. Ions…
Global configuration of Saturn's magnetic field derived from observations
Dougherty, M. K.; Khurana, K. K.; Carbary, J. F. +2 more
Magnetic field observations from the Cassini spacecraft are averaged into 1 × 1 RS (1 RS = 60238 km) meridional bins at Saturn. A Runge-Kutta procedure uses the bin-averaged field components to estimate the global configuration of Saturn's magnetic field and map field lines from the equator to Saturn's ionosphere. Within ∼18 …
Overlapping ionospheric and surface echoes observed by the Mars Express radar sounder near the Martian terminator
Gurnett, D. A.; Morgan, D. D.; Duru, F.
Radar soundings from the Mars Express spacecraft occasionally show ionospheric and surface echoes that overlap in frequency. For specular reflection from a horizontally stratified ionosphere such a frequency overlap is not possible, since ionospheric and surface reflections can only occur at frequencies below and above the maximum ionospheric plas…
Can Cassini magnetic field measurements be used to find the rotation period of Saturn's interior?
Bloxham, Jeremy; Sterenborg, M. Glenn
We investigate the determination of the rotation period of Saturn's interior using magnetic field measurements from Cassini. First, we vary the rotation period and search for the period that yields the smallest rms misfit of a magnetic field model to the data. Second, we search for the period that yields the most power in the non-axisymmetric comp…
Cluster observations of outflowing electron distributions and broadband electrostatic emissions above the polar cap
Belmont, G.; Canu, P.; Fontaine, D. +1 more
We investigate the excellent correlation between ionospheric upgoing electron beams and broadband electrostatic emissions (0-6 kHz) observed by Cluster, at ∼5 to 9 Earth's radii above the polar cap. In the absence of detailed, high time resolution waveform data in that region, we precisely analyzed several electron beams to obtain information conc…