Effects of a subadiabatic layer on convection and dynamos in spherical wedge simulations

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Effects of a subadiabatic layer on convection and dynamos in spherical wedge simulations. / Käpylä, Petri; Viviani, Mariangela; Käpylä, Maarit; Brandenburg, A.; Spada, Federico.

In: GEOPHYSICAL AND ASTROPHYSICAL FLUID DYNAMICS, Vol. 113, No. 1-2, 04.03.2019, p. 149-183.

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@article{72773da05c504181ab997bbc79703242,
title = "Effects of a subadiabatic layer on convection and dynamos in spherical wedge simulations",
abstract = "We consider the effect of a subadiabatic layer at the base of the convection zone on convection itself and the associated large-scale dynamos in spherical wedge geometry. We use a heat conduction prescription based on the Kramers opacity law which allows the depth of the convection zone to dynamically adapt to changes in the physical characteristics such as rotation rate and magnetic fields. We find that the convective heat transport is strongly concentrated towards the equatorial and polar regions in the cases without a substantial radiative layer below the convection zone. The presence of a stable layer below the convection zone significantly reduces the anisotropy of radial enthalpy transport. Furthermore, the dynamo solutions are sensitive to subtle changes in the convection zone structure. We find that the kinetic helicity changes sign in the deeper parts of the convection zone at high latitudes in all runs. This region expands progressively towards the equator in runs with a thicker stably stratified layer.",
keywords = "convection, turbulence, dynamos, magnetohydrodynamics, Convection",
author = "Petri K{\"a}pyl{\"a} and Mariangela Viviani and Maarit K{\"a}pyl{\"a} and A. Brandenburg and Federico Spada",
year = "2019",
month = "3",
day = "4",
doi = "10.1080/03091929.2019.1571584",
language = "English",
volume = "113",
pages = "149--183",
journal = "GEOPHYSICAL AND ASTROPHYSICAL FLUID DYNAMICS",
issn = "0309-1929",
publisher = "Taylor and Francis Ltd.",
number = "1-2",

}

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TY - JOUR

T1 - Effects of a subadiabatic layer on convection and dynamos in spherical wedge simulations

AU - Käpylä, Petri

AU - Viviani, Mariangela

AU - Käpylä, Maarit

AU - Brandenburg, A.

AU - Spada, Federico

PY - 2019/3/4

Y1 - 2019/3/4

N2 - We consider the effect of a subadiabatic layer at the base of the convection zone on convection itself and the associated large-scale dynamos in spherical wedge geometry. We use a heat conduction prescription based on the Kramers opacity law which allows the depth of the convection zone to dynamically adapt to changes in the physical characteristics such as rotation rate and magnetic fields. We find that the convective heat transport is strongly concentrated towards the equatorial and polar regions in the cases without a substantial radiative layer below the convection zone. The presence of a stable layer below the convection zone significantly reduces the anisotropy of radial enthalpy transport. Furthermore, the dynamo solutions are sensitive to subtle changes in the convection zone structure. We find that the kinetic helicity changes sign in the deeper parts of the convection zone at high latitudes in all runs. This region expands progressively towards the equator in runs with a thicker stably stratified layer.

AB - We consider the effect of a subadiabatic layer at the base of the convection zone on convection itself and the associated large-scale dynamos in spherical wedge geometry. We use a heat conduction prescription based on the Kramers opacity law which allows the depth of the convection zone to dynamically adapt to changes in the physical characteristics such as rotation rate and magnetic fields. We find that the convective heat transport is strongly concentrated towards the equatorial and polar regions in the cases without a substantial radiative layer below the convection zone. The presence of a stable layer below the convection zone significantly reduces the anisotropy of radial enthalpy transport. Furthermore, the dynamo solutions are sensitive to subtle changes in the convection zone structure. We find that the kinetic helicity changes sign in the deeper parts of the convection zone at high latitudes in all runs. This region expands progressively towards the equator in runs with a thicker stably stratified layer.

KW - convection

KW - turbulence

KW - dynamos

KW - magnetohydrodynamics

KW - Convection

UR - http://www.scopus.com/inward/record.url?scp=85061240477&partnerID=8YFLogxK

U2 - 10.1080/03091929.2019.1571584

DO - 10.1080/03091929.2019.1571584

M3 - Article

VL - 113

SP - 149

EP - 183

JO - GEOPHYSICAL AND ASTROPHYSICAL FLUID DYNAMICS

JF - GEOPHYSICAL AND ASTROPHYSICAL FLUID DYNAMICS

SN - 0309-1929

IS - 1-2

ER -

ID: 31365132