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Accepted · first revision · record

Title: Why do simulated solar convection speeds exceed helioseismic limits?
Plain: Computer models of the Sun's churning outer layer predict large-scale flows much faster than sound waves inside the Sun appear to allow, and models with solar parameters tend to rotate the wrong way at the equator.
Precise: Global convection simulations at solar luminosity and rotation give large-scale velocities (spherical-harmonic degree below $\sim 30$) above some helioseismic upper limits, and tend toward anti-solar differential rotation (slow equator). Identify the missing physics: low effective Prandtl number, non-local surface-driven convection (entropy rain), a weakly subadiabatic deep layer, or magnetic feedback. Answer: a simulation matching both the helioseismic convective power spectrum and the observed rotation profile.
Settled by: Convergent helioseismic measurements of deep convective velocities by independent methods, matched by a simulation that also reproduces solar differential rotation.
Kind: phenomenon
Answer type: mechanism
References: (empty)
Literature status: contested
Status note: Helioseismic estimates of deep convective velocities from different methods (2012 and 2015) disagree by more than an order of magnitude.
Posed since: 2012