Jet Phenomena associated with Emerging Flux and Magnetic Reconnection
in the Solar Atmosphere 

T. Miyagoshi (Kwasan Obs., Kyoto Univ.)

Recently solar observations have revealed a dynamic behavior of the
solar corona. One of the most interesting phenomena is solar coronal 
X-ray jets, which are observed as transitory X-ray enhancements with 
an apparent collimated motion. We studied solar coronal X-ray jets by 
MHD numerical simulations with heat conduction effect based on the 
magnetic reconnection model. Key physical processes are included, such 
as emergence of magnetic flux from the convection zone, magnetic 
reconnection with the coronal magnetic fields, heat conduction to the 
chromosphere, and the chromospheric evaporation. High-density evaporation 
jets were successfully reproduced in the simulations.
We show the coronal parameter dependence of the evaporation jet mass
and the Mach number ahead the fast shock caused by the reconnection outflow
taken into account the heat conduction effect. We also present our 
numerical simulation results of magnetic reconnection between a twisted 
emerging magnetic flux tube and overlying coronal magnetic fields. 
This process may produce shear Alfv'en wave with helical velocity fields,
because the twist of the flux tube is transported to the outer coronal 
fields through magnetic reconnection process between them.