High-resolution models of solar granulation: the 2D case

TL;DR

This paper presents high-resolution 2D simulations of solar granulation using grid refinement, revealing detailed dynamics like Kelvin-Helmholtz instabilities and acoustic pulse generation, which could impact understanding of solar phenomena.

Contribution

The study introduces high-resolution 2D solar granulation models with grid refinement, capturing detailed flow instabilities and acoustic pulse behaviors not previously resolved.

Findings

Downflows show Kelvin-Helmholtz instabilities

Ubiquitous acoustic pulses generated below the photosphere

Acoustic pulses may influence p-mode excitation and chromospheric heating

Abstract

Using grid refinement, we have simulated solar granulation in 2D. The refined region measures 1.97*2.58 Mm (vertical*horizontal). Grid spacing there is 1.82*2.84 km. The downflows exhibit strong Kelvin-Helmholtz instabilities. Below the photosphere, acoustic pulses are generated. They proceed laterally (in some cases distances of at least the size of our refined domain) and may be enhanced when transversing downflows) as well as upwards where, in the photosphere they contribute significantly to 'turbulence' (velocity gradients, etc.) The acoustic pulses are ubiquitous in that at any time several of them are seen in our high-resolution domain. Their possible contributions to p-mode excitation or heating of the chromosphere needs to be investigated.