The dynamic chromosphere: pushing the boundaries of observations and models

TL;DR

Recent advances in high-resolution observations and sophisticated models of the solar chromosphere have improved our understanding, but discrepancies remain, especially in the quiet Sun, as new observatories promise further insights.

Contribution

The paper reviews recent observational and modeling progress in understanding the solar chromosphere, highlighting challenges and future prospects.

Findings

High-resolution observations reveal dynamic chromospheric structures.

Models have evolved from static to more complex physics but still miss some features.

Adding physics to models narrows the gap between predictions and observations.

Abstract

The interface between the bright solar surface and the million-degree corona continues to hold the key to many unsolved problems in solar physics. Advances in instrumentation now allow us to observe the dynamic structures of the solar chromosphere down to less than 0.1" with cadences of just a few seconds and in multiple polarisation states. Such observational progress has been matched by the ever-increasing sophistication of numerical models, which have become necessary to interpret the complex observations. With an emphasis on the quiet Sun, I will review recent progress in the observation and modelling of the chromosphere. Models have come a long way from 1D static atmospheres, but their predictions still fail to reproduce several key observed features. Nevertheless, they have given us invaluable insight into the physical processes that energise the atmosphere. With more physics being added to models, the gap between predictions and observations is narrowing. With the next generation of solar observatories just around the corner, the big question is: will they close the gap?