Frequent Weak-wind Boundary Layers Using New Analysis Techniques in the Space-time Domain

本研究旨在提高我们对大气最底层弱气流与缓倾斜地形湍流产生的相互作用的理解。对弱风边界层的更好理解可能会导致对冷池形成、破坏性霜冻（包括对当地葡萄园的影响）、雾形成和污染物扩散的更准确的建模。本研究旨在利用详细的时空测量来研究弱风边界层。这些边界层具有非平稳性，其中的湍流通常与平均气流处于非平衡状态。以往对此类边界层的研究大多局限于固定位置的时间数据，因此在研究尺度特性时无法考虑滞后。本研究分析了详细的时空数据，以形成更完整的边界层结构图像。本文将研究这些结构的演变和亚中尺度运动的影响。

This study seeks to improve our understanding of the interaction of weak wind flow in the lowest layer of the atmosphere and generation of turbulence in gently sloping terrain. An improved understanding of weak-wind boundary layers could potentially lead to more accurate modeling of the formation of cold pools, damaging frost (including impact to local vineyards), fog formation, and dispersion of contaminants. This study seeks to investigate weak-wind boundary layers using detailed spatial-temporal measurements. These boundary layers demonstrate non-stationarity and the turbulence in them is generally in a non-equilibrium state with the mean flow. Previous studies of such boundary layers were mostly limited to temporal data at fixed locations, and therefore could not take into account hysteresis when investigating scaling properties. This study analyzes detailed spatial-temporal data to form a more complete picture of boundary layer structures. The evolution of the structures and the impact of the sub-mesoscale motions will be investigated.