Three-Demensional Magnetic Reconnection driven 
by a buoyant flux tube with the coronal arcade field in the Sun

S.Notoya,T.Yokoyama,K.Kusano,T.Sakurai,T.Miyagoshi,T.Maeshiro,T.Yamamoto

Coronal arcade field can be seen often in an active region in which a solar flare is taking place.
As a mechanism of releasing magnetic energy,reconnection is thought to be an important process.
We performed three-dimensional numerical simulations of the emergence of magnetic flux from the 
convectiove zone into the corona and the reconnection with a preexisting ambient coronal arcade field.
Initially the flux tube in the convective zone gets perturbed and becomes unstable to the Parker Instability.
The instability causes the rise and the expansion of the flux tube into the corona and the field comes into
contact with the arcade field. When the upcoming field and the coronal arcade field generate current sheets 
between them,the reconnection occurs,causing profound changes in their connectivity.
The local heating and the high-speed outflows caused by the reconnection can be seen in our simulations.
We investigate  how the changes in the basic parameters such as, magnetic field strength,the width of the arcade,
and the angle of the arcade relative to the magnetic neutral line, lead to the different physical processes.