Spatial and Temporal Characteristics of Horizontal Rolls and Cells in the Atmospheric Boundary Layer Based on Radar and in Situ Observations
Spatial and Temporal Characteristics of Horizontal Rolls and Cells in the Atmospheric Boundary Layer Based on Radar and in Situ Observations
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基于雷达和原位观测的大气边界层水平卷和单元时空特征
DOI：
10.1023/a:1001791408470
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发表时间：
1998
影响因子：
4.3
通讯作者：
B. Campistron
中科院分区：
文献类型：
--
作者：
F. Lohou;A. Druilhet;B. Campistron
本文是一系列致力于观测和分析多云大气边界层（ABL）相干结构（如水平卷或热细胞）的第二篇。在第一篇论文中，TRAC（湍流雷达飞机单元）实验，这是基于耦合雷达-飞机测量的这项研究的观测支持，沿着概述了1993年6月在法国举行的这项活动的主要结果。在这里，分析的重点是空间特征（长度规模，方向...）的相干结构，它们的时间演变和垂直分布推断出的雷达反射率场在晴朗的空气中获得的五个不同的ABL在几个层次上。为此，开发了一种能够提取组织的主要模式的原始且有效的图像处理方法。这些特性的ABL的动态和热力学状态，使用平均值和湍流的信息进行检查，所观察到的现场飞机。这些实验结果的基础上，未来的大涡模拟建模的一个有组织的ABL正在进行中，将关注的第三篇论文在该系列。
This paper is the second of a series devoted to the observation and analysis of coherent structures in the cloudy Atmospheric Boundary Layer (ABL) such as horizontal rolls or thermal cells. In the first paper, the TRAC (Turbulence Radar Aircraft Cells) experiment which is the observational support of this investigation based on coupled radar-aircraft measurements, was presented along with an overview of the main results of this campaign held in June 1993 in France. Here the analysis is focused on the spatial characteristics (length-scale, orientation ... ) of the coherent structures, their temporal evolution and vertical distribution deduced from the radar reflectivity fields acquired in clear air at several levels for five different ABLs. For that, an original and efficient image processing method able to extract the major mode of the organisation was developed. These characteristics are examined in relation to the dynamic and thermodynamic state of the ABL using mean and turbulent information as observed by the in-situ aircraft. These experimental results are the basis of a future Large Eddy Simulation modeling of an organised ABL which is in progress and will be the concern of the third paper in the series.