Modeling the Near-Surface Shear Layer: Diffusion Schemes Studied With CSS

TL;DR

This paper evaluates how different diffusion schemes affect the dynamics and energy flux in solar near-surface shear layer simulations using the new CSS code, which models 3D MHD convection in rotating spherical segments.

Contribution

It introduces the CSS code for realistic 3D MHD solar convection simulations and assesses the impact of diffusion schemes on flow dynamics and energy flux.

Findings

Diffusion schemes significantly influence flow dynamics.

Energy flux balance varies with diffusion treatment.

CSS code enables detailed modeling of the NSSL.

Abstract

As we approach solar convection simulations that seek to model the interaction of small-scale granulation and supergranulation and even larger scales of convection within the near-surface shear layer (NSSL), the treatment of the boundary conditions and minimization of sub-grid scale diffusive processes become increasingly crucial. We here assess changes in the dynamics and the energy flux balance of the flows established in rotating spherical shell segments that capture much of the NSSL with the Curved Spherical Segment (CSS) code using two different diffusion schemes. The CSS code is a new massively parallel modeling tool capable of simulating 3-D compressible MHD convection with a realistic solar stratification in rotating spherical shell segments.