Measuring complex bright-point motion and wave excitation in high-resolution solar observations

Magnetic bright points on the solar photosphere, prominent in the G band but visible in the continuum, indicate footpoints of kilogauss magnetic flux tubes extending to the corona. The horizontal motions of these footpoints are believed to excite MHD waves which propagate to the corona, where they deposit heat through turbulent dissipation. Analyzing this motion can thus constrain MHD-wave energy transport and provide a key lower boundary condition in coronal and heliospheric models. At ~100 km in diameter, most bright points are unresolved. Traditional tracking of their centroids allows kink-mode wave excitation to be modeled in the overlying flux tubes. However, centroid tracking cannot easily handle the merging or splitting of bright points nor can it adequately track extremely long, thin bright points. First-light images from DKIST have resolved the sizes and shapes of bright points, and future science observations will reveal the time evolution of these high-resolution details, which is expected to excite higher-order flux-tube waves. But centroid tracking cannot analyze this more detailed motion, and even in a study limited to kink-mode waves, Agrawal et al. (2018) and Van Kooten & Cranmer (2017) have shown that centroid tracking applied to DKIST observations of bright points is likely to experience a strong, spurious "jitter" signal due to the high spatial and temporal resolution. We present initial results from efforts on multiple fronts to overcome these limitations, including an algorithm to infer the horizontal plasma velocity field inside bright points at DKIST-like resolution (at which bright points are resolved but not large enough for traditional correlation-tracking techniques). These inferred velocity fields assist in the modeling of higher-order waves generated in the overlying flux tubes. By preparing our approaches using output data from high-resolution MURaM simulations now, our new approach will be ready to analyze upcoming DKIST data as it becomes available. This work will enable estimates of the significance of the contribution to the coronal heating budget of more complex waves generated by small-scale motions and so provide a more complete lower boundary condition for coronal and heliospheric models.