Implementation of whistler suppression in 1D and 2D with the MTI. Part (a): 1D simulation illustrating the behavior of whistler-suppressed thermal conduction. The temperature (top), plasma β (middle, kept fixed), and thermal conductivity (bottom) are shown at different times (in units of L²/χ₀, with L the box size). For this 1D example the suppression factor has the form χ/χ₀ = (1 + LβdlnT/dx)⁻¹ such that heat conduction is suppressed at strong temperature gradients and high β. Temperature equilibration thus occurs faster on the right (where β is low) than on the left (where β is high). Part (b): Snapshots at saturation of 2D MTI turbulence with a similar form of whistler suppression (Eq. (3)). Shown are temperature fluctuations (top), the Boussinesq equivalent of plasma beta (middle), and the spatially varying heat conductivity χ (bottom). The suppression of χ is seen to spatially correlate with regions of high . The MTI-driven temperature fluctuations reveal that the MTI continues to work despite the whistler suppression of the thermal diffusivity, which amounts to 20% of χ₀ (volume average).