Convection Cells in the Planetary Boundary Layer: Origin and Reduced Modeling

行星边界层中的对流单元：起源和简化模型

• 批准号: 315590231
• 负责人: Professor Dr. Juan Pedro Mellado
• 金额: --
• 依托单位: Meteorologisches Institut (MI)
• 依托单位国家: 德国
• 项目类别: Priority Programmes
• 财政年份: 2016
• 资助国家: 德国
• 起止时间: 2015-12-31 至 2019-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/315590231?language=en
• 关键词: Convection; Cells; Planetary; Boundary; Layer

Under free-convection conditions, the flow in the planetary boundary layer is organized in long-lived, large-scale cellular motions. We want to investigate these superstructures. In particular, we want to ascertain how important the boundary conditions are for their formation and evolution, and how we can represent them in simple atmospheric models. We will employ data from direct numerical simulations. Starting from Rayleigh-Bénard convection, we will incrementally modify the boundary conditions to design and study convective boundary layers, which are idealized configurations that reproduce key aspects of the atmospheric flow. The aim is to understand the dependence of superstructures on the boundary conditions, and on the Rayleigh number. For the detection of the superstructures and the analysis of their interaction with the small-scale turbulence, we will use coarse-graining and Lagrangian techniques. As an outcome of this work, we will comprehensively learn how efficient these techniques are to represent superstructures in the planetary boundary layer. Besides, this project will bring together Rayleigh-Bénard convection and atmospheric convection in one single analysis, assessing thereby to what extent we can transfer knowledge between the two fields.

在自由对流条件下，行星边界层中的流动是长时间的、大规模的细胞运动。我们想要研究这些上层建筑。特别是，我们想确定边界条件对它们的形成和演化有多重要，以及我们如何在简单的大气模式中表示它们。我们将采用直接数值模拟的数据。从瑞利-巴姆纳德对流开始，我们将逐步修改边界条件来设计和研究对流边界层，对流边界层是再现大气流动关键方面的理想配置。目的是了解上部结构对边界条件和瑞利数的依赖性。对于上层结构的检测和分析它们与小尺度湍流的相互作用，我们将使用粗粒化和拉格朗日技术。作为这项工作的结果，我们将全面了解这些技术如何有效地表示行星边界层中的上层建筑。此外，这个项目将把瑞利-巴姆萨纳德对流和大气对流结合在一起进行分析，从而评估我们在多大程度上可以在两个领域之间传递知识。