Wednesday

Flux emergence is a crucial source of complex magnetic field structure in the corona. State of the art simulations indicate emergence is a vital mechanism behind phenomena such as coronal heating, jets, flaring and CME's. Observationally the most reliable information on the magnetic field structure emerging into this region is through photospheric magnetograms (standard and vector). In comparing simulated and observational emerging magnetogram data there are often significant differences in the variation in magnetic field structure; primarily that the helicity input of observational data shows far more variation than the simulations (which often focus on idealised twisted flux rope emergence). In an attempt to characterise the variation in helicity input structure we have preformed simulations of mixed helicity flux rope structures emerging into the corona; this includes fields with helicity across varying spatial scales. One crucial aspect of this study was an attempt to characterise effect on the helicity input due to the variation in geometry of the simulation's photosphere, represented by a fixed density value. It is found this effect is significant, highlighting the fact that the ability of future missions such as DKIST to resolve the variation in field structure across the photosphere could have a critical impact on our ability to determine what kind of magnetic field structure the sun is transporting into its corona.