Constraints on high-latitude solar rotation rate at r = 0.8 R_⊙. The green cross shows the constraint from the HL1 mode frequency (2010–2024), according to Eq. (5), with the horizontal bar indicating the width of the kernel. The green curve shows the rotation rate Ω_ref(r, θ)+ΔΩ(θ; A) for A/2π = 13.6 nHz, and the green shaded region indicates the associated uncertainty (see Fig. 3). The p-mode reference rotation rate Ω_ref(0.8 R_⊙, θ) is given by the red dashed curve. The red cross shows a p-mode OLA estimate at the target location (0.8 R_⊙, θ = 15° ) obtained from yearly HMI inversions (Howe 2009) averaged over 2010–2023. The horizontal bar represents the width of the averaging kernel, while the vertical bar represents the random error.