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Proposing Institution

Leibniz-Institut für Astrophysik Potsdam (AIP)
Project Manager

Dr. Petri Käpylä
An der Sternwarte 16
14482 Potsdam
Current simulations of the Sun lead to convective velocities at large horizontal scales that are significantly higher than those obtained from helioseismology. The most striking manifestation of this is that simulations at solar rotation rate and luminosity lead to anti-solar differential rotation with a slow equator and fast poles, opposite to the Sun. The likely reason is that the simulation setups lead to convection at the scale of the domain whereas in the Sun convection may only be excited near the surface. What is commonly viewed as the deep convection zone in the Sun is then mixed by plumes of cool matter pummeling through a slightly subadiabatic, and thus stably stratified, atmosphere. This process is referred to as cool 'entropy rain'. This would mean that the largest convective scale in the Sun could be as small as the granulation pattern observed at the surface (a few Mm) instead of the inferred depth of the convection zone (200 Mm). We employ the Pencil Code to produce advanced convection models where the depth of the convection zone is not a priori fixed, and set out to study the effects of entropy rain for stellar differential rotation and dynamos.

Impressum, Conny Wendler