Top and middle panels: Temporal variations of the m = 1 mode amplitude extracted from B_los and V_los data, respectively. The red, orange, green, and blue curves correspond to results from the HMI $⟨B_{\mathrm{avg}}^{+}⟩$, HMI $⟨V_{\mathrm{zonal}}^{-}⟩$, GONG $⟨B_{\mathrm{avg}}^{+}⟩$, and GONG $⟨V_{\mathrm{zonal}}^{-}⟩$ datasets, respectively. Shaded regions indicate the 68% confidence interval, estimated using 10 000 Monte Carlo simulations. Open circles denote instances where the excess power near the mode frequency falls below the 90% confidence level. We note that $⟨V_{\mathrm{zonal}}^{-}⟩$ was derived directly from the LOS Doppler velocity (Eqs. (4)–(6)); unlike LG25, we did not apply a multiplicative factor to scale the $⟨V_{\mathrm{zonal}}^{-}⟩$ amplitudes to match the horizontal velocities from the ring-diagram maps. Vertical lines denote key phases of the solar cycle, with solid lines representing solar minima and dashed lines indicating solar maxima. Bottom panel: Average sunspot number (source: WDC-SILSO, Royal Observatory of Belgium, Brussels, https://doi.org/10.24414/qnza-ac80).