TURBULENT TRANSITION IN SOLAR SURGES

It has been suggested that a surge can be modelled as a jet travelling in a sheared magnetic field, and that the transition to turbulence of this ''MHD tearing jet'' can explain several key observed features. I n this paper we present our preliminary results of the transition to t urbulence via secondary instabilities of the MHD tearing jet. Our resu lts confirm that turbulent transition can decelerate the surge, with d ecay times which compare well with surge data. Furthermore, we find th at the turbulent MHD tearing jet forms magnetic field-aligned velocity filaments similar to those often observed in the surge flow field.