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We present results from a pair of high resolution, long timescale ($\sim10^5GM/c^3$), global, three dimensional magnetohydrodynamical accretion disksimulations with differing initial magnetic plasma $\beta$ in order to studythe effects of initial toroidal field strength on production of large-scalepoloidal field. We initialize our disks in approximate equilibrium with purelytoroidal magnetic fields of strength $\beta_0=5$ and $\beta_0=200$. We alsoperform a limited resolution study. We find that simulations of differing fieldstrength diverge early in their evolution and remain distinct over the timestudied, indicating that initial magnetic conditions leave a persistent imprintin our simulations. Neither simulation enters the Magnetically Arrested Disk(MAD) regime. Both simulations are able to produce poloidal fields frominitially-toroidal fields, with the $\beta_0=5$ simulation evolving clear signsof a large-scale poloidal field. We make a cautionary note that computationalartifacts in the form of large-scale vortices may be introduced in thecombination of initially-weak field and disk-internal mesh refinementboundaries, as evidenced by the production of an $m=1$ mode overdensity in theweak field simulation. Our results demonstrate that the initial toroidal fieldstrength plays a vital role in simulated disk evolution for the models studied.

Magnetic field evolution in high and low $\beta$ disks with initially-toroidal fields