Magnetic bright points on the solar photosphere, visible in both continuum and G-band images, 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 provide a power spectrum of MHD wave energy transport, which is a key lower boundary condition in coronal and heliospheric models. At 100 km in diameter, most bright points are seen as unresolved blobs. Tracking their centroids allows the excitation of kink-mode waves to be modeled in the overlying flux tubes. However, centroid tracking cannot easily handle the merging or splitting of bright points nor can it track extremely long bright points, and current observations cannot reveal more complicated motions, such as size or shape changes, which are expected to excite higher-order waves. DKIST promises to resolve the sizes and shapes of bright points. However, Agrawal et al. (2018) showed that centroid tracking is likely to experience a spurious "jitter" signal when applied to high-resolution data, and this limitation is in addition to the inability of centroid tracking to produce new insights from the new size and shape information. We present efforts to overcome these limitations by developing an algorithm to infer the horizontal plasma flow inside bright points at DKIST-like resolution (at which bright points are resolved but not large enough for traditional correlation-tracking techniques) and using these inferred flows to model the higher-order waves generated in the overlying flux tubes. By using output data from high-resolution MURaM simulations now, we expect to be prepared to analyze DKIST images soon after they become available next year. This work will estimate the significance of the contribution to the coronal heating budget of these more complex waves and so provide a more complete lower boundary condition for coronal and heliospheric models.
American Astronomical Society Meeting Abstracts #234
- Pub Date:
- June 2019