IAFE   05512
INSTITUTO DE ASTRONOMIA Y FISICA DEL ESPACIO
Unidad Ejecutora - UE
artículos
Título:
The variability of Titan's magnetic environment
Autor/es:
C. BERTUCCI B. SINCLAIR, N. ACHILLEOS, P. HUNT, M.K. DOUGHERTY, C.S. ARRIDGE
Revista:
PLANETARY AND SPACE SCIENCE
Editorial:
Elsevier
Referencias:
Año: 2009
ISSN:
0032-0633
Resumen:
With a mean orbital radius of 20.2 Saturnian radii (1 Saturn radius RS=60,330 km),
Titan is usually located within the kronian magnetosphere. 3.5 years of
Cassini magnetometer observations in the vicinity of Titan's orbit
reveal that the moon's magnetic environment is strongly affected by the
presence of Saturn's magnetodisk. As a result of the disk's
solarwind-induced asymmetry, Titan is exposed to quasi-dipolar fields
in the noon sector, and planetward, swept-back fields in the dawn, dusk
and midnight sectors. These magnetic properties indicate that the moon
is, on average, south of the central current sheet and immersed in
Saturn's rotating magnetospheric plasma for all local times (SLT). At a
given SLT, Titan's distance from the central current sheet associated
with the magnetodisk depends on the solar wind pressure and on the
phase of the Saturn's kilometric radiation (SKR). The influence of the
solar wind is present at all SLT (although dominant in the noon
sector), whereas the SKR modulation seems to affect the magnetic field
to first-order at least in the dawn sector. Near dawn local times,
Titan tends to be farther from the disk at SKR longitudes around 140° and closer to it for longitudes around 320°.
Depending on these factors, Titan is exposed to either: (i) a
magnetodisk lobe regime where the plasma beta is low and fields are
radially stretched and usually stronger or (ii) a current sheet
regimecharacterized by quasi-dipolar, relatively weak fields and a
high-beta plasma.