IIA Institutional Repository

Consequences of high effective prandtl number on solar differential rotation and convective velocity

Show simple item record

dc.contributor.author Karak, B. B
dc.contributor.author Miesch, Mark
dc.contributor.author Bekki, Y
dc.date.accessioned 2020-11-27T12:55:34Z
dc.date.available 2020-11-27T12:55:34Z
dc.date.issued 2018-04
dc.identifier.citation Physics of Fluids, Vol. 30, No. 4, 046602 en_US
dc.identifier.issn 1089-7666
dc.identifier.uri http://prints.iiap.res.in/handle/2248/7508
dc.description Restricted Access © American Institute of Physics https://doi.org/10.1063/1.5022034 en_US
dc.description.abstract Observations suggest that the large-scale convective velocities obtained by solar convection simulations might be over-estimated (convective conundrum). One plausible solution to this could be the small-scale dynamo which cannot be fully resolved by global simulations. The small-scale Lorentz force suppresses the convective motions and also the turbulent mixing of entropy between upflows and downflows, leading to a large effective Prandtl number (Pr). We explore this idea in three-dimensional global rotating convection simulations at different thermal conductivity (κ), i.e., at different Pr. In agreement with previous non-rotating simulations, the convective velocity is reduced with the increase of Pr as long as the thermal conductive flux is negligible. A subadiabatic layer is formed near the base of the convection zone due to continuous deposition of low entropy plumes in low-κ simulations. The most interesting result of our low-κ simulations is that the convective motions are accompanied by a change in the convection structure that is increasingly influenced by small-scale plumes. These plumes tend to transport angular momentum radially inward and thus establish an anti-solar differential rotation, in striking contrast to the solar rotation profile. If such low diffusive plumes, driven by the radiative-surface cooling, are present in the Sun, then our results cast doubt on the idea that a high effective Pr may be a viable solution to the solar convective conundrum. Our study also emphasizes that any resolution of the conundrum that relies on the downward plumes must take into account the angular momentum transport and heat transport. Published by AIP Publishing. en_US
dc.language.iso en en_US
dc.publisher American Institute of Physics en_US
dc.title Consequences of high effective prandtl number on solar differential rotation and convective velocity en_US
dc.type Article en_US

Files in this item

This item appears in the following Collection(s)

Show simple item record

Search DSpace


My Account