Constraining the Structure and Dynamics of the Upper Layers of the Convective Zone Using Accurate High Spatial Degree Modes Derived from GONG Observations

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Our modern society is highly dependent on technology for all of its critical activities, including navigation, commerce, transportation, communication, power provision, and security. As a magnetic star, our Sun has disrupted, and will continue to threaten disrupting, these technology-dependent activities. In order to mitigate the inevitable risks, it is vital that we advance our understanding of the processes behind events such as flares and coronal mass ejections (CME). The solar magnetic field that underlies all of these phenomena arises from the flows present in the solar plasma. These flows are produced by the transport of energy through the solar interior. This 3-year research project is expected to improve our knowledge of the structure, dynamics and flows immediately below the surface of the Sun. This region is key to understanding and predicting solar activity. This research project features not only important academic research, but also promises a tangible and concrete benefit to our technologically powered society.This 3-year project is aimed at a better characterization of the Sun's near-surface layers (outermost 5% of the solar interior) using helioseismic techniques. A key question that this work will contribute to answering is: how and why does the Sun (and other Sun-like stars) vary? Using helioseismology, the project team will be able to infer and constrain changes in the structure and dynamics of the solar interior by extending the precise characterization of p-mode (or pressure-mode) oscillations to higher spatial degrees and tracking their changes with time. The technical aspect of this project is to derive accurate characteristics of high-degree modes, i.e., precise and unbiased estimates of mode frequency, line width, asymmetry and amplitude for spherical harmonics degrees in the range 200-900, using NSO's Global Oscillations Network Group (GONG) observations. The research work to be carried out would enhance the scientific return of the GONG mission, which has been supported by the NSF. Therefore, the project supports the Strategic Goals of the AGS Division in discovery, learning, diversity, and interdisciplinary research.