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Description
We investigate the post-flare amplification of chromospheric 3-minute oscillations within a sunspot umbra following the SOL2024-08-08 X1.3-class flare. Utilizing high-resolution data from the DKIST Visible Broadband Imager at 450 nm and the AR30THz telescope focused on AR13777, we demonstrate the global dominance of 5-minute oscillations and the strict localization of 3-minute modes within the deep umbral photosphere. By spatially cross-correlating the deep photospheric wave field with the mid-infrared chromosphere, we measure a near-zero representative phase lag of 3.2 +/- 1.88s, consistent with the sub-cutoff evanescent nature of the waves, whereby the entire squeezed umbral column oscillates in unison as a phase-locked coherent unit. We then reveal a temporal disconnect (~54 minutes) between the flare’s impulsive phase and the sustained 30 THz wave amplification. We conclude that two sequential processes were required: the impulsive flare provided the initial mechanical perturbation that excited the natural oscillation frequencies of the umbral column, while delayed, gradual thermodynamic density enhancement subsequently altered the local H- and free-free opacity. This opacity tuning physically shifted the 30 THz formation height upward by ~200–250 km into the oscillating umbral chromosphere, allowing the wave power to permanently cross the 95% significance threshold. These results establish the mid-infrared continuum as an essential, scatter-free diagnostic for tracking how mechanical wave energy is processed and dissipated within the dynamic lower solar atmosphere.