Leptocline as a shallow substructure of near-surface shear layer in 3D radiative hydrodynamic simulations
Leptocline as a shallow substructure of near-surface shear layer in 3D radiative hydrodynamic simulations
复制标题
3D 辐射流体动力学模拟中作为近地表剪切层浅层子结构的轻斜层
DOI：
10.1093/mnras/stac2946
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发表时间：
2022
影响因子：
4.8
通讯作者：
Guerrero, G
中科院分区：
文献类型：
--
作者：
Kitiashvili, Irina N;Kosovichev, A G;Wray, A A;Sadykov, V M;Guerrero, G
了解太阳对流区的旋转驱动效应对于许多与太阳活动相关的问题至关重要，例如微分旋转的形成、经向环流等。我们分析了位于30°纬度的80 Mm宽，25 Mm深的局部区域内存在旋转的太阳地下动力学的真实三维辐射流体动力学模拟。模拟结果表明，近地表剪切层（NSSL）形成了一个10 Mm深的浅层亚结构，其特征是强烈的径向旋转梯度和自组织的经向流动。这个浅层（“细斜”）位于氢电离区，与增强的各向异性超调型流相关，流入氢和氦电离区之间较不稳定的层。我们讨论了目前关于薄斜存在的观测证据，并表明从该层模拟得到的微分旋转和经向流动剖面的径向变化与日震观测定性地一致。
Understanding the effects driven by rotation in the solar convection zone is essential for many problems related to solar activity, such as the formation of differential rotation, meridional circulation, and others. We analyse realistic 3D radiative hydrodynamics simulations of solar subsurface dynamics in the presence of rotation in a local domain 80 Mm wide and 25 Mm deep, located at 30° latitude. The simulation results reveal the development of a shallow 10 Mm deep substructure of the near-surface shear layer (NSSL), characterized by a strong radial rotational gradient and self-organized meridional flows. This shallow layer (‘leptocline’) is located in the hydrogen ionization zone associated with enhanced anisotropic overshooting-type flows into a less unstable layer between the H and Heiiionization zones. We discuss current observational evidence of the presence of the leptocline and show that the radial variations of the differential rotation and meridional flow profiles obtained from the simulations in this layer qualitatively agree with helioseismic observations.