ReCon² will use full-physics, ultra-high-resolution simulations to test the true nature of solar convection and address one of the longest-standing open problems in solar physics.
Tackling the solar convection challenge
The interior of the Sun is in constant motion: hot plasma rises, cooler plasma sinks, and this churning convection helps drive everything from sunspots to the solar magnetic cycle.
- Yet for decades, numerical simulations of the Sun’s convection zone have not matched what helioseismic observations infer about internal flow speeds.
This mismatch, known as the convective conundrum, has been one of the longest-standing open problems in solar physics, explains Andrius.
The new FRIPRO project ReCon² (Resolving the Solar Convective Conundrum) will use state-of-the-art 3D simulations on some of the world’s largest supercomputers to put this puzzle to a decisive test.
Led by Dr. Andrius Popovas at the Rosseland Centre for Solar Physics (RoCS), the project will combine all the key physical ingredients that previous global models could not treat simultaneously:
- fully compressible magnetohydrodynamics
- realistic solar stratification
- surface-cooling–driven convection
- small-scale magnetic dynamo action, at ultra-high spatial resolution
ReCon² will attack the problem on two fronts:
First, “mini-Sun” simulations will resolve turbulent convection and magnetic fields in a deep local Cartessian box that extends from below the solar convection zone all the way to the visible surface.
Second, these results will be tested against a full-sphere global model of the solar convection zone, directly confronting helioseismic constraints on flow speeds and patterns.
A dedicated set of experiments will also settle a long-running debate over whether poorly known microphysical parameters – such as the effective Prandtl number – actually control the outcome of global simulations, or whether sufficient resolution is the real key.
All simulation data, analysis tools and code developments will be shared under FAIR and open-source principles, making ReCon² a community resource for solar and stellar astrophysics.
If successful, the project will show that the convective conundrum does not signal missing physics deep inside the Sun, but rather that earlier models were simply not realistic enough, setting a new standard for global “full-physics” simulations of stars.