Collaborative Research: Intercomparison of 3D MHD simulations of the solar photosphere and observations: a case study in preparation for the DKIST era

One of the most pressing problems in understanding Earth?s climate is solar irradiance: the amount of light emitted by the Sun. Solar irradiance is the sole source of heating on Earth. If we want to understand our climate, we must understand the source of the sunlight that warms our planet.

The proposed work will examine two different high-resolution magnetohydrodynamic models of the Sun in an effort to understand how magnetic variability at small scales (down to tens of kilometers) can affect irradiance. The team will compare the results of the two different models to high-resolution measurements of the Sun from the NSF?s Dunn Solar Telescope and from NASA?s Solar Dynamics Observatory.

The result of this work will be a greater understanding of solar irradiance variability, which will lead to a better understanding of the external influences on the Earth?s climate. This work will form the basis of a graduate student?s PhD thesis.

The proposed work is to examine the results of two different three-dimensional magnetohydrodynamic simulations of the solar photosphere for solar irradiance at small (~10 km) scales. Simulated spectra will be generated by BAERI?s StellarBox code and from NCAR/HAO?s MURaM code and compared to observations of the Sun from the Dunn Solar Telescope and from the Solar Dynamics Observatory spacecraft.

The team will assess the contribution to solar irradiance in certain spectral ranges from magnetic features too small to be resolved in moderate-resolution imaging. They will also examine the effects of different numerical schemes and approximations used in the two different MHD codes to predicted overall irradiance. The overall objective will be to identify the most suitable numerical contributions for advancing irradiance reconstruction and stellar atmosphere models.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.