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, List of all 51 simulations discussed in this paper. Ra is the reference Rayleigh number (see equation (2)). Simulations are run with a stiffness parameter S, and with n x Fourier and n z Chebyshev basis functions in the horizontal and vertical directions. Timesteps were taken using the Courant-Friedrichs-Levy (CFL) condition, with a safety factor given in the table. dt is the typical time step, and each simulation was run for at least O(1) thermal time (about dt ?1 timesteps). The aspect ratio of all simulations is 2, TABLE I: (Cont.), 2013.

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, 15: Same as figure 8 but for the higher Rayleigh number Ra = 8 × 10 8 case

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