Heating of the upper Solar Atmosphere – confronting models with observations (Heat)

Heating in the solar atmosphere takes place on different spatial scales.

On the one hand, the sources of heating can be found in small vortex/tornado-like flows on scales of a few tens of kilometers.

On the other hand, violent explosions can heat material over a few hundred thousand kilometers and often result in coronal mass ejection (CME). Our understanding of the physical processes that drive these phenomena at different spatial scales is limited.

The ultimate question, still unsolved in modern solar physics is: why are the outer parts of the solar atmosphere so hot? What sustains the temperature of millions of degrees?

To answer this question and trace the sources of heating, we follow a unique approach: (1) we produced 3D models of the solar atmosphere that go clearly beyond the state-of-the-art and enable us to perform a 1-to-1 comparison with observations (2) we generate realistic synthetic observations which help us to develop better strategies for interpreting convoluted signals coming from the Sun (3) we have a unique inversion tool for faithful interpretation of the solar observations  (4) we have access to the full solar atmosphere by combining the new groundbreaking observations from space (Solar Orbiter, Solar Dynamics Observatory, Interface Region Imaging Spectrograph and Hinode) and balloon (Sunrise III) with (5) our Swedish 1-m Solar Telescope that provides, at the moment, the best observations of the solar chromosphere.