magnetic field.[]{data-label="INIT"}](figure3.eps){height="8cm"}

In this study, 3D conservative ideal MHD equations were used. Constant gravitational acceleration was assumed, but viscosity, diffusion, heat conduction and radiative cooling terms were neglected and an ideal gas was assumed. The equations were non-dimensionalised using the sound speed ($C_s=13.2$kms$^{-1}$), the pressure scale height ($\Lambda=C_s/(\gamma g)= R_gT/(\mu g)=6.1 \times 10^7$ cm), the density at the centre of the prominence ($\rho (x=0)=10^{-12}$ g cm$^{-3})$ and the temperature ($T_0=10^4$K), giving a characteristic timescale of $\tau=\Lambda/C_s=47$s. The ratio of specific heats was set as $\gamma=1.05$ and $\beta=0.5$. A full description of the simulations can be found in @HILL2012.

Description of simulated plumes {#SIMPlume}
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Panel (a) of Figure \[plumerise\] shows the density distribution at the centre of the the Kippenhahn-Schlüter model as the rising plumes, created by the magnetic Rayleigh-Taylor instability move upward through the dense prominence material. The plume in the box, more like a bubble in this image but really a low-density tube, is the plume we use for this comparison. Note that we didn’t have to choose a plume that has detached from its tail, as we are only interested in the density at the head of the plume.

![Panel (a) shows the rising plumes that are 