Characteristics of cold pools observed in narrow valleys and dependence on external conditions
Characteristics of cold pools observed in narrow valleys and dependence on external conditions
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狭窄山谷中观察到的冷池特征及其对外部条件的依赖性
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
A. Brown
中科院分区：
文献类型：
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作者：
P. F. Sheridan;S. Vosper;A. Brown
最近的冷空气汇集实验（COLPEX）现场活动的观测结果用于将两个小山谷（O（100 m）深和O（1 km）宽）内的冷池强度与经过山谷的气团内的流动条件联系起来。冷池的温度结构进行了检查，使用地面传感器通过山谷和无线电探空仪从山谷内释放的横断面，以评估简单的二维概念的冷池形成由于遮蔽。强冷池发生的不同夜晚，冷池的时空结构是一致的。最初，山谷内的所有点都发生了类似的急剧表面反转，等熵线大致与地形平行。谷底的逆温层随后变得更深，在谷底部分扩展，跨谷等熵线最终变成水平的。通过定义冷池内相对温降的适当测量值，以及根据接近流的速度和稳定性诊断的无量纲谷深，测量结果与先前针对简单二维谷确定的关系一致。
Observations from the recent COLd‐air Pooling EXperiment (COLPEX) field campaign are used to relate the intensity of cold pools within two small valleys (O(100 m) depth and O(1 km) width) to flow conditions within the airmass passing over the valley. The temperature structure of the cold pools is examined using transects of ground‐based sensors through the valleys and radiosonde releases from within the valley, in order to evaluate simple two‐dimensional concepts of cold‐pool formation due to sheltering. The cold‐pool spatial and temporal structure is found to be consistent between different nights when strong cold pools occurred. Initially a sharp surface inversion occurs similarly at all points within the valley, with isentropes roughly terrain‐parallel. The inversion layer at the bottom of the valley then grows deeper, spreading over the bottom portion of the valley, and cross‐valley isentropes eventually become horizontal. By defining appropriate measures of the relative temperature drop within the cold pool, and non‐dimensional valley depth diagnosed with respect to the speed and stability of the approaching flow, the measurements are shown to be consistent with previous relationships determined for simple two‐dimensional valleys.
COLPEX：小丘陵地区的实地和数值研究
影响因子：
8
作者：
Price J
通讯作者：
Price J