Effect of Air‐Sea Environmental Conditions and Interfacial Processes on Extremely Intense Typhoon Haiyan (2013)
Effect of Air‐Sea Environmental Conditions and Interfacial Processes on Extremely Intense Typhoon Haiyan (2013)
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DOI：
10.1029/2017jd028139
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发表时间：
2018-09
期刊：
影响因子：
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通讯作者：
A. Wada;S. Kanada;H. Yamada
中科院分区：
文献类型：
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作者：
A. Wada;S. Kanada;H. Yamada
台风海燕（2013）迅速增强，中心气压在温暖的西北太平洋上空达到895 hPa。为了弄清海燕为何会成为如此强烈的热带气旋，我们研究了大气和海洋条件以及海气界面过程对海燕强度的影响。我们用许多不同的初始海洋条件和一个7公里网格的大气-波浪-海洋耦合模式进行了集合实验。我们还进行了敏感性实验，以检查海浪的影响和使用2 km网格水平分辨率。此外，对台风迈克（1990年）进行了类似的实验，它遵循类似的路径，但强度低于海燕。对于这两个TC，海洋耦合有助于减轻不同的预先存在的海洋条件所造成的模拟强度的不确定性。海气潜热通量的增加有助于增加这两种TC的强度，尽管海洋喷雾的效果取决于白浪覆盖。先前存在的海洋条件和海气界面过程通过潜热通量和近地表水汽流入的变化直接影响了二次环流。然而，2 km网格分辨率仅改善了海燕的模拟，强度区的平均潜热通量不足以模拟强度。偏东风和850 hPa的比湿度决定了模拟海燕的尺度小，平移快，海面冷却少，摩擦辐合区下方的潜热通量减少少。了解已有海洋条件和海-气界面过程对模拟TC的影响，将为改进大气-波浪-海洋耦合模式提供指导。
Typhoon Haiyan (2013) intensified rapidly and reached a central pressure of 895 hPa over the warm northwestern Pacific. To clarify why Haiyan became such an extraordinarily intense tropical cyclone (TC), we investigated the impacts of atmospheric and oceanic conditions and air‐sea interfacial processes on Haiyan's intensity. We performed ensemble experiments with many different initial oceanic conditions and a 7‐km‐mesh atmosphere‐wave‐ocean coupled model. We also performed sensitivity experiments to examine the impacts of sea spray and use of a 2‐km‐mesh horizontal resolution. Also, analogous experiments were performed with Typhoon Mike (1990), which followed a similar track but was less intense than Haiyan. For both TCs, ocean coupling helped alleviate uncertainty in the simulated intensities caused by different preexisting oceanic conditions. Increases in air‐sea latent heat fluxes helped increase the intensity of both TCs although the effect of sea spray depended on whitecap coverage. Preexisting oceanic conditions and air‐sea interfacial processes directly affected the secondary circulation via changes in latent heat fluxes and near‐surface moisture influxes. However, the 2‐km‐mesh resolution improved only Haiyan's simulation; the mean latent heat flux over the strength area was insufficient to simulate the intensity. It was easterly winds and specific humidity at 850 hPa that determined the small size, rapid translation, less sea surface cooling, and small decreases in latent heat fluxes beneath the frictional convergence area of simulated Haiyan. Understanding of the effect of preexisting oceanic conditions and air‐sea interfacial processes on simulated TCs will serve as a guideline for improvement of the atmosphere‐wave‐ocean coupled model.