HR: 1340h
AN: P43A-1014    [Abstracts]
TI: Plasma Convection and Injections in Kronian Magnetosphere
AU: * Ukhorskiy, A
EM: ukhorskiy@jhuapl.edu
AF: JHU/APL, Applied Physics Laboratory 11100 Johns Hopkins Road, Laurel, MD 20723, United States
AU: Sitnov, M
EM: mikhail.sitnov@jhuapl.edu
AF: JHU/APL, Applied Physics Laboratory 11100 Johns Hopkins Road, Laurel, MD 20723, United States
AU: Rymer, A
EM: abigail.rymer@jhuapl.edu
AF: JHU/APL, Applied Physics Laboratory 11100 Johns Hopkins Road, Laurel, MD 20723, United States
AU: Mauk, B
EM: barry.mauk@jhuapl.edu
AF: JHU/APL, Applied Physics Laboratory 11100 Johns Hopkins Road, Laurel, MD 20723, United States
AB: Steady-state access of plasma from the magnetotail to the inner magnetosphere of Saturn is hampered by the large size of corotation-dominated region which extends all the way to the dayside magnetopause (~20RS). Production of plasma by Saturn's moons (e.g. oxygen ions from Enceladus) has been identified as a dominant driver of plasma convection in the inner magnetosphere. Mass loading of flux tubes results in their outward convection and consequent stretching of magnetic field lines consistent with observed disc-like magnetic field configuration. Since the new plasma material does not produce any additional magnetic flux, magnetic field stretching is limited. The convection crisis can be resolved via bursts of magnetic reconnection and partial tailward release of plasma in plasmoids. Flux tubes after reconnection are more tenuous and hotter due to non- adiabatic heating processes. Their volume per unit magnetic flux also decreases, which provides the buoyancy force moving flux tubes back inwards towards the planet. We show that while the outward plasma convection is smooth, the inward injections of the hot plasma observed by the Cassini CAPS instrument are inherently bursty. The injections events can be attributed to reconnection and consequent inward motion of entropy-depleted flux tubes. We present stability analysis which includes corotation effects and possible generation of field-aligned currents.
DE: 6275 Saturn
DE: 7829 Kinetic waves and instabilities
DE: 7835 Magnetic reconnection (2723, 7526)
DE: 7846 Plasma energization
DE: 7859 Transport processes
SC: Planetary Sciences [P]
MN: 2007 Fall Meeting