Physical sizes within the three subregions shown in Figure 2. Here, we show four different sizes of boxes, the full region size at 2.7 × 10⁵ km (k = 2.3 × 10⁻⁵ km⁻¹), half the region size at 1.4 × 10⁵ km (k = 4.8 × 10⁻⁵ km⁻¹), and boxes near the limits of our spectral slope measurements at 6.3 × 10⁴ km (k = 10⁻⁴ km⁻¹), and 6.3 × 10³ km (k = 10⁻³ km⁻¹). We mark the two smallest boxes with their size in k-space as they are representative of the range of sizes we are probing in our linear fits.