Effect of planetary boundary layer schemes on the development of intense tropical cyclones using a cloud-resolving model
Effect of planetary boundary layer schemes on the development of intense tropical cyclones using a cloud-resolving model
复制标题
DOI：
10.1029/2011jd016582
复制
发表时间：
2012-02
影响因子：
--
通讯作者：
S. Kanada;A. Wada;M. Nakano;T. Kato
中科院分区：
文献类型：
--
作者：
S. Kanada;A. Wada;M. Nakano;T. Kato
我们利用日本气象厅开发的2公里网格非流体静力大气模式（NHM2）研究了行星边界层（PBL）在极强热带气旋（TC）强度和内核结构中的作用。为了研究PBL对模拟tc的影响，我们使用了4种PBL方案：2.5级和3级Mellor-Yamada-Nakanishi-Niino关闭方案、非局部方案和Deardorff-Blackadar方案。数值结果表明，即使在表面粗糙度长度、海气动量和传热系数相同的情况下，PBL方案确定的亚网格尺度混合长度对最大TC强度和内核结构的确定也起着关键作用。不同的垂直涡旋扩散系数值导致TC强度、内核结构以及最大风速与中心压力的关系存在差异。特别是，低层（高度<300 m）的垂直涡旋扩散系数较大，导致大量的热量和水汽传递，从而产生极强烈的tc，并伴有垂直收缩的眼壁结构。我们还利用5 km网格非流体静力大气模式（NHM5）和相同的PBL方案进行了数值实验，以研究水平分辨率对模拟tc的影响。NHM5不足以准确表示极强TC的MWS或CP，这表明需要NHM2来模拟以直立、收缩眼壁结构为特征的极强TC。
[1] We studied the role of the planetary boundary layer (PBL) in intensity and inner core structure of extremely intense tropical cyclones (TC) using a 2 km mesh nonhydrostatic atmospheric model (NHM2) developed for operational use by the Japan Meteorological Agency. To investigate the effects of the PBL on simulated TCs, we used four PBL schemes: level 2.5 and level 3 Mellor-Yamada-Nakanishi-Niino closure schemes, a nonlocal scheme, and the Deardorff-Blackadar scheme. The numerical results indicated that the subgrid-scale mixing length determined by the PBL scheme plays a critical role in the determination of maximum TC intensity and inner core structure, even when the same expressions are provided for surface roughness lengths and the air-sea momentum and heat transfer coefficients. Different vertical eddy-diffusivity coefficient values derived from the PBL schemes cause differences in the TC intensity, inner core structure, and the relationship between maximum wind speed (MWS) and central pressure (CP). In particular, large vertical eddy diffusivities in lower layers (height <300 m) lead to large heat and water vapor transfers, resulting in extremely intense TCs accompanied by an upright, contracted eyewall structure. We also conducted numerical experiments using a 5 km mesh nonhydrostatic atmospheric model (NHM5) and the same PBL schemes to investigate the effect of horizontal resolution on simulated TCs. The NHM5 was insufficient to accurately represent the MWS or CP of an extremely intense TC, suggesting that NHM2 is required to simulate an extremely intense TC characterized by an upright, contracted eyewall structure.