INVESTIGADORES
BERTUCCI Cesar
congresos y reuniones científicas
Título:
Titan s plasma wake geometry from RPWS and MAG observations
Autor/es:
MODOLO, R.; CANU, P.; BERTUCCI, C.; ROSENQVIST, L.; KURTH, W. S.; GURNETT, D.; DOUGHERTY, M. K.
Reunión:
Congreso; EGU General Assembly 2009; 2009
Resumen:
Up to now, several tens of Titan flybys have been successfully completed
by Cassini and have revealed a highly dynamic structure of the near
space environment of Titan. The upstream condition of the plasma flow is
expected to affect Titan's induced magnetosphere. The Titan's plasma
wake has been investigated using observations from the Radio and Plasma
Wave Science (RPWS) instruments (Gurnett et al, 2004) and the dual
Magnetometer Technique MAG instruments (Dougherty et al, 2004). Electric
field emissions were detected by the RPWS antennas during Cassini passes
through Titan's wake. These narrow band emissions are identified as
upper hybrid resonance emissions and therefore can provide a density
estimate of the Titan's cold plasma. Some of Titan's wake flybys show a
very strong asymmetry between the inbound and the outbound pass. Good
examples are Ta and Tb flybys (Wahlund et al, 2005). Both flybys have a
similar trajectory in Titan Interaction coordinate System (TIIS) and
have the same illumination condition but the density profiles present
major differences. Some of the Cassini flybys have been set back in the
DRAP coordinate system (Neubauer et al, 2006) such that the upstream
direction of the magnetic field is fixed, in order to determine the
geometry of the plasma wake and study asymmetries. Maps of cold plasma
in Titan's environment are presented. Information concerning the
geometry of the wake is crucial to estimate accurately the plasma
escape. Dougherty, M. K., et al. (2004), The Cassini Magnetic Field
Investigation, Space Sci. Rev, 114, 331- 383,
doi:10.1007/s11214-004-1432-2 Gurnett, D. A., et al. (2004), The Cassini
radio and plasma wave investigation, Space Sci. Rev., 114, 395- 463,
doi:10.1007/s11214-004-1434-0 Neubauer, F. M., et al. (2006), Titan's
near magnetotail from magnetic field and electron plasma observations
and modeling: Cassini flybys TA, TB, and T3, J. Geophys. Res., 111,
A10220, doi:10.1029/2006JA011676 Wahlund, J.-E., et al. (2005), Cassini
measurements of cold plasma in the ionosphere of Titan, Science, 308,
986 - 989, doi:10.1126/ science.1109807