HR: 10:35h
AN: SH42A-02 [Abstracts]
TI: Effects of a Tilted Heliospheric Current Sheet in the Heliosheath: 3D MHD Modeling
AU: * Opher, M
EM: merav.opher@jpl.nasa.gov
AF: Jet Propulsion Laboratory, MS 169-506, 4800 Oak Grove Drive, Pasadena, CA 91109
United States
AU: Liewer, P
EM: paulett.liewer@jpl.nasa.gov
AF: Jet Propulsion Laboratory, MS 169-506, 4800 Oak Grove Drive, Pasadena, CA 91109
United States
AU: Velli, M
EM: marcov@df.unipi.it
AF: Jet Propulsion Laboratory, MS 169-506, 4800 Oak Grove Drive, Pasadena, CA 91109
United States
AU: Gombosi, T
EM: tamas@umich.edu
AF: Space Physics Research Laboratory, Department of Atmospheric Sciences, 1517 Space Research Building,
Ann Arbor, MI 48109-2143
United States
AU: Manchester, W
EM: chipm@umich.edu
AF: Space Physics Research Laboratory, Department of Atmospheric Sciences, 1517 Space Research Building,
Ann Arbor, MI 48109-2143
United States
AU: DeZeeuw, D
EM: darrens@umich.edu
AF: Space Physics Research Laboratory, Department of Atmospheric Sciences, 1517 Space Research Building,
Ann Arbor, MI 48109-2143
United States
AU: Toth, G
EM: gtoth@grid.engin.umich.edu
AF: Space Physics Research Laboratory, Department of Atmospheric Sciences, 1517 Space Research Building,
Ann Arbor, MI 48109-2143
United States
AB:
Recent observations indicate that Voyager 1, now beyond 90 AU, is in a region unlike any
encountered in it's
26 years of exploration. There is currently a controversy as to whether Voyager 1 has already
crossed the
Termination Shock, the first boundary of the Heliosphere (Krimigis et al. 2003; McDonald et al.
2003,
Burlaga et al. 2003). An important aspect of this controversy is our poor understanding of this
region.
The region between the Termination Shock and the Heliopause, the Helisheath, is one of the
most unknown regions
theoretically. In the Heliosheath magnetic effects are crucial, as the solar magnetic field is
compressed at the Termination
Shock by the slowing flow. Therefore, to accurately model the Heliosheath the inclusion of the
solar magnetic field is crucial. Recently,
our simulations showed that the Heliosheath presents remarkable dynamics, with turbulent
flows and a presence
of a jet flow at the current sheet that is unstable due to magnetohydrodynamic instabilities
(Opher et al. 2003; 2004).
We showed that to capture these phenomena, spatial numerical resolution is a crucial
ingredient, therefore requiring
the use of an adaptive mesh refinement (AMR). These previous works assumed that the solar
rotation and the magnetic axis were aligned.
Here we present for the first time results including the tilt of the heliocurrent sheet using a 3D
MHD AMR simulation,
with BATS-R-US code. We discuss the effects on the global structure of the Heliosheath, the
flows, turbulence
and magnetic field structure. We assess the consequences for the observations measured by
Voyager 1 since mid-2002.
UR: http://butch.engin.umich.edu/~merav
DE: 7524 Magnetic fields
DE: 7811 Discontinuities
DE: 7839 Nonlinear phenomena
DE: 7843 Numerical simulation studies
DE: 7863 Turbulence
SC: SPA-Solar and Heliospheric Physics [SH]
MN: 2004 AGU Fall Meeting