The Sun is our nearest star; it is also the most important star that determines life on Earth. A large variety of phenomena observed on the Sun’s surface, with potential impact on Earth, is thought to arise from turbulent convection in Sun’s interior, this being the dominant mode of heat transport within the outer envelope at $r\gtrsim 0.715R_{\odot }$. However, convection in the Sun differs in most of its aspects from convection processes known on Earth, certainly those under controlled laboratory conditions, thus seriously challenging existing physical models of convective turbulence and boundary conditions in the Sun. Solar convection is a multiscale-multiphysics phenomenon including the transport of mass, momentum, and heat in the presence of rotation, dynamo action, radiation fluxes, and partial changes in chemical composition. Standard variables of state such as pressure, mass density, and temperature vary over several orders of magnitude within the convection region, thus introducing immense stratification. Although the Sun has been explored intensely, observational evidence on the structure and intensity of turbulent convection processes remains indirect and essentially limited to observations of the granular convection patterns at the surface and helioseismologic data that probe the propagation of sound waves in the interior. In this Colloquium characteristic scales and dimensionless parameters are discussed, particularly from the perspective of laboratory convection, a research field that has progressed significantly in the last few decades. The estimates and calculations of solar conditions given here are based mostly on the standard solar model S of Christensen-Dalsgaard et al., which is a mean field model of solar convection. Light is shed on existing results to gain a deeper understanding of dynamical aspects of solar convection.

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座谈会：太阳对流的不寻常动力

太阳是离我们最近的恒星；它也是决定地球生命的最重要恒星。人们认为，在太阳表面观测到的各种现象可能对地球产生影响，这是由于太阳内部的湍流对流引起的，这是在外层外壳内传热的主要方式。$\mathrm{[R}\gtrsim 0.715{\mathrm{[R}}_{\odot }$。但是，太阳对流的大部分方面都与地球上已知的对流过程不同，当然也可以在受控实验室条件下进行，这严重挑战了太阳对流湍流和边界条件的现有物理模型。太阳对流是一种多尺度，多物理场的现象，包括质量，动量和热量在旋转，发电机作用，辐射通量和化学成分发生部分变化的情况下的传输。状态标准变量（例如压力，质量密度和温度）在对流区域内变化了几个数量级，因此引入了巨大的分层。尽管太阳已经被强烈探索，关于湍流对流过程的结构和强度的观测证据仍然是间接的，并且基本上仅限于对表面颗粒对流模式的观测以及探测内部声波传播的流变学数据。在本次座谈会中，特别是从实验室对流的角度讨论了特征尺度和无量纲参数，该领域在过去的几十年中取得了长足的发展。此处给出的太阳条件的估计和计算主要基于Christensen-Dalsgaard的标准太阳模型S 在本次座谈会中，特别是从实验室对流的角度讨论了特征尺度和无量纲参数，该领域在过去的几十年中取得了长足的发展。此处给出的太阳条件的估计和计算主要基于Christensen-Dalsgaard的标准太阳模型S 在本次座谈会中，特别是从实验室对流的角度讨论了特征尺度和无量纲参数，该领域在过去的几十年中取得了长足的发展。此处给出的太阳条件的估计和计算主要基于Christensen-Dalsgaard的标准太阳模型S等。，这是太阳对流的平均场模型。可以利用现有的结果来深入了解太阳对流的动力学方面。