INVESTIGADORES
BERTUCCI Cesar
artículos
Título:
Time-dependent global MHD simulations of Cassini T32 flyby: From magnetosphere to magnetosheath
Autor/es:
Y.J. MA; C. T. RUSSELL; A.F. NAGY; G. TOTH; C. BERTUCCI; M. K. DOUGHERTY; F.M. NEUBAUER; A. WELLBROCK; A.J. COATES; P. GARNIER; J.E. WAHLUND; T.E. CRAVENS; F.J. CRARY
Revista:
JOURNAL OF GEOPHYSICAL RESEARCH
Editorial:
AMER GEOPHYSICAL UNION
Referencias:
Año: 2009 p. 1 - 13
ISSN:
0148-0227
Resumen:
When the Cassini spacecraft flew by Titan on 13 June 2007, at 13.6
Saturn local time, Titan was directly observed to be outside Saturn′s
magnetopause. Cassini observations showed dramatic changes of magnetic
field orientation as well as other plasma flow parameters during the
inbound and outbound segments. In this paper, we study Titan's
ionospheric responses to such a sudden change in the upstream plasma
conditions using a sophisticated multispecies global MHD model.
Simulation results of three different cases (steady state, simple
current sheet crossing, and magnetopause crossing) are presented and
compared against Cassini Magnetometer, Langmuir Probe, and Cassini
Plasma Spectrometer observations. The simulation results provide clear
evidence for the existence of a fossil field that was induced in the
ionosphere. The main interaction features, as observed by the Cassini
spacecraft, are well reproduced by the time-dependent simulation cases.
Simulation also reveals how the fossil field was trapped during the
interaction and shows the coexistence of two pileup regions with
opposite magnetic orientation, as well as the formation of a pair of new
Alfven wings and tail disconnection during the magnetopause crossing
process.