Influence Of Density Stratification On Solar Convection (Solar Studies)

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The outer 30% of the Sun by radius is convecting. In this region, thermal gradients cause the fluid plasma to overturn. Currently, observations do not agree on the size of these convective motions and furthermore, discrepancies also occur between observations and numerical models of the Sun. This research project aims to address the uncertainty surrounding the length scale and amplitude of motions in the convection zone. This work also aims to shed light on how large-scale, convection-driven flows impact heat transport in the Sun and what the consequences of this are for the interior dynamics. Understanding the dynamics of the solar convection zone is crucial in understanding how the Sun builds its magnetic field through dynamo action. The Sun's magnetic field has a direct impact on Earth through space weather events such as solar storms which can disrupt satellite communications and power grids, and so a better understanding of the solar dynamo is key to predicting space weather events. To achieve these aims, two important physical aspects of the Sun must be considered. Namely, that it is rotating, and that its density drops off significantly over its depth. In this project, using a series of numerical simulations, we will investigate the important effects of rotation and density stratification and determine how key convective quantities scale with rotation rate in the presence of significant density stratification. We expect the depth-dependence introduced by density stratification to be fundamental in determining the heat transport and size of convection motions throughout the solar convection zone.