Search Publications
Magnetic reconnection in Saturn's magnetotail: A comprehensive magnetic field survey
Thomsen, M. F.; Jackman, C. M.; Smith, A. W.
Reconnection within planetary magnetotails is responsible for locally energizing particles and changing the magnetic topology. Its role in terms of global magnetospheric dynamics can involve changing the mass and flux content of the magnetosphere. We have identified reconnection related events in spacecraft magnetometer data recorded during Cassin…
Rotational modulation of Saturn's radio emissions after equinox
Gurnett, D. A.; Kurth, W. S.; Ye, S. -Y. +2 more
Saturn kilometric radiation (SKR), narrowband emission, and auroral hiss are periodically modulated due to Saturn's rotation, and the periods were found to vary with time. We analyze Cassini observations of Saturn's radio emissions with the main focus on the four years 2012-2015. It is shown that the rotation rates of SKR north and south were diff…
Reconnection events in Saturn's magnetotail: Dependence of plasmoid occurrence on planetary period oscillation phase
Jackman, C. M.; Cowley, S. W. H.; Provan, G.
During its exploration of Saturn's magnetotail the Cassini magnetometer has detected many in situ examples of magnetic reconnection, in the form of plasmoids, traveling compression regions (TCRs), and dipolarizations. Meanwhile, many magnetospheric phenomena have been shown to be organized with particular regularity by planetary period oscillation…
Cassini observations of Saturn's southern polar cusp
Coates, A. J.; Krupp, N.; Russell, C. T. +15 more
The magnetospheric cusps are important sites of the coupling of a magnetosphere with the solar wind. The combination of both ground- and space-based observations at Earth has enabled considerable progress to be made in understanding the terrestrial cusp and its role in the coupling of the magnetosphere to the solar wind via the polar magnetosphere…
Field-aligned currents in Saturn's magnetosphere: Local time dependence of southern summer currents in the dawn sector between midnight and noon
Coates, A. J.; Dougherty, M. K.; Alexeev, I. I. +6 more
We examine and compare the magnetic field perturbations associated with field-aligned ionosphere-magnetosphere coupling currents at Saturn, observed by the Cassini spacecraft during two sequences of highly inclined orbits in 2006/2007 and 2008 under late southern summer conditions. These sequences explore the southern currents in the dawn-noon and…
Characterization of Saturn's bow shock: Magnetic field observations of quasi-perpendicular shocks
Dougherty, M. K.; Masters, A.; Sulaiman, A. H.
Collisionless shocks vary drastically from terrestrial to astrophysical regimes resulting in radically different characteristics. This poses two complexities. First, separating the influences of these parameters on physical mechanisms such as energy dissipation. Second, correlating observations of shock waves over a wide range of each parameter, e…
Source region and growth analysis of narrowband Z-mode emission at Saturn
Gurnett, D. A.; Coates, A. J.; Santolík, O. +5 more
Intense Z-mode emission is observed in the lower density region near the inner edge of the Enceladus torus at Saturn, where these waves may resonate with MeV electrons. The source mechanism of this emission, which is narrow-banded and most intense near 5 kHz, is not well understood. We survey the Cassini Radio and Plasma Wave Science data to isola…
Transport of magnetic flux and mass in Saturn's inner magnetosphere
Lai, H. R.; Russell, C. T.; Jia, Y. D. +2 more
It is well accepted that cold plasma sourced by Enceladus is ultimately lost to the solar wind, while the magnetic flux convecting outward with the plasma must return to the inner magnetosphere. However, whether the interchange or reconnection, or a combination of the two processes is the dominant mechanism in returning the magnetic flux is still …
Pulsations of the polar cusp aurora at Saturn
Krupp, N.; Roussos, E.; Mitchell, D. G. +4 more
The magnetospheric cusp is a region connecting the interplanetary environment to the ionosphere and enabling solar wind particles to reach the ionosphere. We report the detection of several isolated high-latitude auroral emissions with the Ultraviolet Imaging Spectrograph of the Cassini spacecraft. We suggest that these auroral spots, located in t…
Cassini plasma observations of Saturn's magnetospheric cusp
Coates, Andrew J.; Krupp, Norbert; Arridge, Christopher S. +6 more
The magnetospheric cusp is a funnel-shaped region where shocked solar wind plasma is able to enter the high-latitude magnetosphere via the process of magnetic reconnection. The plasma observations include various cusp signatures such as ion energy dispersions and diamagnetic effects. We present an overview analysis of cusp plasma observations at t…