Rpws Science Today and in Cassini's Final Three Year

Abstract:

Ten years of Cassini/RPWS remote and in situ observations of Saturn and its environment have provided a rich return feeding numerous studies of the various types of kronian radio emissions (such as Saturn’s kilometric radiation [SKR], auroral hiss, narrowband [NB] and drifting burst emissions, and Saturn’s electrostatic discharges [SED]), local plasma waves (such as chorus, upper hybrid bands and electron cyclotron harmonic emissions) and dusty plasmas. Nonetheless, several major objectives for RPWS science remain for the last three years of the Cassini mission, and will culminate with the detailed study of Saturn’s auroral regions, where SKR and possibly other types of radio waves are produced and large-scale plasma acceleration is suspected to take place. During the F-ring and proximal orbital sequences, Cassini is expected to pass through northern and southern auroral regions tens of times around noon local time. These passes can be accurately predicted through the modeling of SKR sources and in turn help to trigger combined observations with other Cassini instruments and Earth-based observatories such as Hubble. Altogether, these observations will provide crucial complementary insights to understand kronian auroral processes. RPWS will also continue to measure the rotational modulation of various radio emissions (SKR, NB and hiss), pushing forward the study of magnetospheric periodicities long after equinox, pursue the monitoring of SEDs and lightning whistlers, whose occurrence probes the activity of atmospheric storms, or probe in detail the dusty environment of the D ring and wave-particle interactions taking place in the very inner magnetosphere where the magnetic field links the planet to the rings.