Spatial sensitivity of the frequency of the HL1 mode to localized changes in the background rotation rate. The kernel K(r, θ) is symmetric across the equator. Grid sizes dr = 2.3 Mm and dθ = 2° were used for this calculation. For reference, a patch of area 10dr × 2rdθ = 20dΣ is outlined with a solid black contour. The dashed black contour corresponds to the value of the kernel at half maximum.