Same as Figure 1, but for the logarithmic, rms-normalized temperature, ﹩T/{\langle {T}^{2}\rangle }^{1/2}﹩ (left in each panel), and mass density, ﹩\rho /{\langle {\rho }^{2}\rangle }^{1/2}﹩ (right in each panel). The SNRs exhibit diverse morphologies depending on their age (radii). Young SNRs are nearly spherical, with only high-k modes present in the thin density interface, the contact discontinuity, between the hot (red) and warm (blue) plasma. Older SNRs develop highly fractal interfaces, where denser, cooler plasma penetrates deep into the remnant.