INVESTIGADORES
BERTUCCI Cesar
congresos y reuniones científicas
Título:
Real-time Global MHD Simulations of Cassini T32 Flyby
Autor/es:
AUTHORS: MA, YINGJUAN; CRARY, FRANK; RUSSELL, CHRISTOPHER; NAGY, ANDREW; BERTUCCI, CESAR; NEUBAUER, FRITZ; DOUGHERTY, MICHELE; CRAVENS, THOMAS; COATES, ANDREW; WAHLUND, JAN-ERIK
Reunión:
Congreso; 37th COSPAR Scientific Assembly; 2008
Resumen:
Cassini Spacecraft made a special pass of Titan on June 13, 2007. This
flyby, referred to as T32 flyby, is the first occasion that Titan was
observed to be outside Saturn's magnetopause (Bertucci et al., 2007).
During the flyby, Titan encountered an abrupt change in the magnetic
field. Other plasma parameters such as electron density and temperatures
also changed dramatically during the pass (Coates et al., 2007). In this
presentation, we study Titan's ionospheric responses to such a sudden
change in the upstream plasma flow, using a sophisticated multi-species
global MHD model. As a first attempt, we simplify the condition to a
thin current sheet (represented by a tangential discontinuity) crossing
along the flow direction, and simulate in real-time the interaction
process of Titan's ionosphere with such a current sheet. Our simulation
results show that the interaction causes magnetic reconnection at the
upstream mass-loading region and subsequently at the distant tail. There
is a good agreement between the observations and the magnetic field
predicted by our model, especially for the outbound segment. We also
show results with the current sheet moving toward Saturn (perpendicular
to the flow direction) with plasma parameters constrained by the Cassini
plasma observations, as well as data-model comparisons.