Determining Boundary-Layer Height from Aircraft Measurements
Determining Boundary-Layer Height from Aircraft Measurements
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DOI：
10.1007/s10546-014-9929-z
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发表时间：
2014-06
影响因子：
4.3
通讯作者：
C. Dai;Q. Wang;J. Kalogiros;D. Lenschow;Z. Gao;M. Zhou
中科院分区：
文献类型：
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作者：
C. Dai;Q. Wang;J. Kalogiros;D. Lenschow;Z. Gao;M. Zhou
大气边界层高度是观测研究和模式模拟中的一个重要变量。获得机载边界层高度最常用的测量方法是雷达探测剖面。中尺度或区域尺度模式使用基于预报变量的廓线的大量理查森数。在这里，我们评估了几种常用的方法来定义ABL高度从一个单一的配置文件的局限性，并确定最佳阈值为每种方法，如果配置文件是唯一可用的测量。飞机测量从五个领域的项目，代表了各种ABL条件，包括稳定，对流，云顶边界层在不同的下垫面。从这些方法中检测到的ABL高度进行了验证，从飞机探测，其中ABL高度被定义为显着的湍流层的顶部确定的“真”值。检测率被定义为表示ABL高度用特定方法正确诊断的频率。结果表明，温度梯度法提供了最合理的估计，虽然不同类型的ABL的检测率和合适的检测标准各不相同。理查森数的方法，另一方面，在大多数情况下，是不充分的或劣于其他方法，尝试。在本研究中检查的所有ABL类型的检测标准的最佳范围。
The height of the atmospheric boundary layer (ABL) is an important variable in both observational studies and model simulations. The most commonly used measurement for obtaining ABL height is a rawinsonde profile. Mesoscale or regional scale models use a bulk Richardson number based on profiles of the forecast variables. Here we evaluate the limitations of several frequently-used approaches for defining ABL height from a single profile, and identify the optimal threshold value for each method if profiles are the only available measurements. Aircraft measurements from five field projects are used, representing a variety of ABL conditions including stable, convective, and cloud-topped boundary layers over different underlying surfaces. ABL heights detected from these methods were validated against the ‘true’ value determined from aircraft soundings, where ABL height is defined as the top of the layer with significant turbulence. A detection rate was defined to denote how often the ABL height was correctly diagnosed with a particular method. The results suggest that the temperature gradient method provides the most reasonable estimates, although the detection rate and suitable detection criteria vary for different types of ABL. The Richardson number method, on the other hand, is in most cases inadequate or inferior to the other methods that were tried. The optimal range of the detection criteria is given for all ABL types examined in this study.