| 摘要: |
| 台风强度预报误差较大,相关物理机制有待深入研究。针对台风“海马”个例,利用台风最佳路径数据集和欧洲中心再分析资料设定台风特征参数,使用基于海-气相互作用理论的简单台风模型对台风“海马”进行数值模拟,并针对焓交换系数与拖曳系数比值开展敏感性试验。控制试验结果表明,在台风的成熟期,台风的切向动能主要存在于眼壁外侧的云下层和对流层中下层,而径向动能主要集中在对流层上部和眼壁外侧的云下层,这些结果描述了台风成熟期的基本特征。敏感性试验表明,当海洋表面焓交换系数与拖曳系数的比值增大时,台风的主级环流与次级环流明显增强,台风边界层的平均径向风速度分布更趋向中心,且风速明显增加,同时,垂直上升速度增加,台风切向动能明显增加,台风强度增强。研究结果有助于理解海气交换对台风强度的影响。 |
| 关键词: 台风 台风强度变化 海表面焓交换系数 数值模拟 |
| DOI：10.11759/hykx20220318002 |
| 分类号:P732.3,P444 |
| 基金项目:上海交通大学“深蓝计划”项目(SL2020MS030);卫星海洋环境动力学国家重点实验室资助项目(SOEDZZ2206) |
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| Physical mechanism of the intensity change of Typhoon Haima based on a simple typhoon model |
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YANG Qian, HE Hai-lun
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State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of Oceanography, MNR, Hangzhou 310012, China
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| Abstract: |
| Typhoon intensity forecast errors are generally large. The physical mechanism related to typhoon intensity variation warrants further investigation. In this work, the best track dataset and ECMWF reanalysis were employed to set the parameters of a typhoon and a simple typhoon model based on wind-induced surface heat exchange was adopted to simulate Typhoon Haima. Furthermore, sensitivity tests on the surface enthalpy exchange and drag coefficients were conducted to study the effect of air–sea exchange on the intensity variation of Typhoon Haima. The findings revealed that in the mature stage of the typhoon, the tangential velocity kinetic energy is mainly concentrated in the subcloud layer, which is outside the eye wall, and the middle and lower tropospheres. Meanwhile, the radial velocity kinetic energy is mainly concentrated in the upper troposphere and the subcloud layer, which is outside the eye wall. These results reflect the basic characteristics of the typhoon in the mature stage. The sensitivity experiments of the surface turbulence exchange coefficient show that when the ratio of surface enthalpy exchange and drag coefficients increases, the primary and secondary circulations of the typhoon are considerably intensified, the mean radial wind velocity in the boundary layer tends to be centralized, the wind speed considerably increases, vertical ascent velocity increases, tangential kinetic energy considerably increases, and typhoon intensity increases. In summary, this work would help understand the influence of air–sea exchange on the variation in typhoon intensity. |
| Key words: typhoon typhoon intensity change sea surface enthalpy exchange coefficient numerical simulation |
