Transition of the Hurricane Boundary Layer during the Landfall of Hurricane Irene (2011)
Transition of the Hurricane Boundary Layer during the Landfall of Hurricane Irene (2011)
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DOI：
10.1175/jas-d-19-0290.1
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发表时间：
2020-10
影响因子：
3.1
通讯作者：
A. Alford;Jun A. Zhang;M. Biggerstaff;P. Dodge;F. Marks;D. Bodine
中科院分区：
文献类型：
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作者：
A. Alford;Jun A. Zhang;M. Biggerstaff;P. Dodge;F. Marks;D. Bodine
通过对公海上空热带气旋的飞机调查，已经对飓风边界层（HBL）进行了详细的观测，但对HBL的沿海过渡的观测较少。在飓风艾琳（Irene）登陆期间（2011年），研究和水上作战飞机与陆上研究和作战多普勒雷达同时对公海HBL进行采样。雷达的位置为沿海地区提供了13小时的双多普勒分析。因此，首次对沿海水道、沿海过渡和陆上的HBL进行了非常详细的观测。发现了三种HBL结构。外带的特征是HBL结构的时间扰动，在雨带附近伴随有低空极大风。相比之下，内核没有产生这样的扰动，但确实看到了最大风高度的降低和更像射流的HBL风廓线。在眼壁上，观察到一个切向风最大值，在过去的研究中，在HBL的水面上，在HBL的陆上。然而，切向风极大值通过沿海过渡的转变表明，极大值在内陆5 km处继续存在于HBL，这是以前没有观测到的。结果表明，HBL对海岸表面粗糙度不连续性的调整不会立即混合高空残余高动量急流。因此，在HBL完全调整之前，离海岸最近的社区可能会经历最强的陆上风。
The hurricane boundary layer (HBL) has been observed in great detail through aircraft investigations of tropical cyclones over the open ocean, but the coastal transition of the HBL has been less frequently observed. During the landfall of Hurricane Irene (2011), research and operational aircraft over water sampled the open-ocean HBL simultaneously with ground-based research and operational Doppler radars onshore. The location of the radars afforded 13 h of dual-Doppler analysis over the coastal region. Thus, the HBL from the coastal waterways, through the coastal transition, and onshore was observed in great detail for the first time. Three regimes of HBL structure were found. The outer bands were characterized by temporal perturbations of the HBL structure with attendant low-level wind maxima in the vicinity of rainbands. The inner core, in contrast, did not produce such perturbations, but did see a reduction of the height of the maximum wind and a more jet-like HBL wind profile. In the eyewall, a tangential wind maximum was observed within the HBL over water as in past studies and above the HBL onshore. However, the transition of the tangential wind maximum through the coastal transition showed that the maximum continued to reside in the HBL through 5 km inland, which has not been observed previously. It is shown that the adjustment of the HBL to the coastal surface roughness discontinuity does not immediately mix out the residual high-momentum jet aloft. Thus, communities closest to the coast are likely to experience the strongest winds onshore prior to the complete adjustment of the HBL.