Exploring the Dynamics of Near-Surface Solar Convection with Helioseismology

<p>I present a new implementation of local helioseismology along with observations of near-surface solar\&nbsp;<span style="line-height: 1.6em;">convection made with this method. The upper 5\% of the solar radius (35 Mm) is known as the Near-Surface\&nbsp;</span><span style="line-height: 1.6em;">Shear Layer (NSSL) and is characterized by strong rotational shear. While the physical origin of this layer\&nbsp;</span><span style="line-height: 1.6em;">remains unknown, current theories point to convective motions playing an important role. In this thesis I\&nbsp;</span><span style="line-height: 1.6em;">investigate the properties of convection in the NSSL using a newly-developed high-resolution ring-diagram\&nbsp;</span><span style="line-height: 1.6em;">analysis. I present measurements of the speeds and spatial scales of near-surface flows and from these infer\&nbsp;</span><span style="line-height: 1.6em;">that the degree of rotational constraint on convective flows varies significantly across this layer. In depth\&nbsp;</span><span style="line-height: 1.6em;">analysis of the convective patterns reveals the pervasive influence of coherent downflow plumes generated at\&nbsp;</span><span style="line-height: 1.6em;">the photosphere. These structures link the convective pattern of supergranulation seen in surface observations\&nbsp;</span><span style="line-height: 1.6em;">with the deeper motions found within the NSSL and further hint at the importance of rotation in this layer.</span></p>
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University of Colorado Boulder
Boulder, CO
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