AAS 200th meeting, Albuquerque, NM, June 2002
Session 3. Solar Magnetic Fields
Display, Monday, June 3, 2002, 9:20am-6:30pm, SW Exhibit Hall

## [3.06] The Rise of Twisted Horizontal Flux Tubes in a 3D Convecting Flow

Y. Fan (HAO/NCAR, ITP/UCSB), W. P. Abbett, G.H. Fisher (SSL/UCB, ITP/UCSB)

We present 3D numerical simulations of the dynamic evolution of twisted horizontal magnetic flux tubes in a stratified convecting convection zone. We investigate how the trajectory, rise velocity, and cohesion of the buoyant flux tubes are affected by the 3D stratified convection. It is found that the field strength of the magnetic flux tube needs to be significantly above the value of equipartition with the kinetic energy of convection in order for the flux tube to rise cohesively to the top of the stratified domain. These simulations add further support to the strong toroidal field strength (~5 \times 104 G to 105 G) at the base of the solar convection zone, suggested by previous thin flux tube calculations of emerging flux tubes through the solar convective envelope.

NCAR is sponsored by the National Science Foundation. Part of this work was carried out while the authors were participating in the solar magnetic field program held at ITP, UCSB.

Bulletin of the American Astronomical Society, 34
© 2002. The American Astronomical Soceity.