Dynamics of Saturn's magnetodisk near Titan's orbit: Comparison of Cassini magnetometer observations from real and virtual Titan flybys

Authors
Simon, Sven; Wennmacher, Alexandre; Neubauer, Fritz M.; Bertucci, Cesar; Kriegel, Hendrik; Russell, Christopher T.; Dougherty, Michele K.
Publication Year
2010
Language
English
Format
article
Status
Published version
Description
We analyze the variability of the ambient magnetospheric field along Titan’s orbit at 20.3 Saturn radii. However, while our preceding study (Simon et al., 2010) focused on Cassini magnetometer observations from the 62 Titan flybys (TA–T62) between October 2004 and October 2009, the present work discusses magnetic field data that were collected near Titan’s orbit when the moon was far away. In analogy to the observations during TA–T62, the magnetospheric fields detected during these 79 ‘‘virtual’’ Titan flybys are strongly affected by the presence of Saturn’s bowl-shaped and highly dynamic magnetodisk current sheet. We therefore provide a systematic classification of the magnetic field observations as magnetodisk current sheet or lobe-type scenarios. Among the 141 (62 real+79 virtual) crossings of Titan’s orbit between July 2004 and December 2009, only 17 encounters (9 real+8 virtual) took place within quiet, magnetodisk lobe-type fields. During another 50 encounters (21 real+29 virtual), rapid transitions between current sheet and lobe fields were observed around the moon’s orbital plane. Most of the encounters (54¼22 real+32 virtual) occurred when Titan’s orbit was embedded in highly distorted current sheet fields, thereby invalidating the frequently applied idealized picture of Titan interacting with a homogeneous and stationary magnetospheric background field. The locations of real and virtual Titan flybys are correlated to each other. Each of the 62 real Titan flybys possesses at least one virtual counterpart that occurred shortly before or after the real encounter and at nearly the same orbital position. A systematic comparison between Cassini magnetometer observations from the real Titan flybys and their virtual companions suggests that there is no clear evidence of Titan exerting a significant level of control on the vertical oscillatory motion of the magnetodisk near its orbit.
Fil: Simon, Sven. University of Cologne; Alemania
Fil: Wennmacher, Alexandre. University of Cologne; Alemania
Fil: Neubauer, Fritz M.. University of Cologne; Alemania
Fil: Bertucci, Cesar. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina
Fil: Kriegel, Hendrik. Institute for Theoretical Physics; Alemania
Fil: Russell, Christopher T.. University of California; Estados Unidos
Fil: Dougherty, Michele K.. Imperial College London; Reino Unido
Subject
Titan
Saturn's magnetosphere
Magnetodisk current sheet and lobes
Cassini flybys
Astronomía
Ciencias Físicas
CIENCIAS NATURALES Y EXACTAS
Access level
Restricted access
License
https://creativecommons.org/licenses/by-nc-sa/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/20444