西北太平洋台风与黑潮/暖涡相互影响机制研究

Each year the number of typhoons in the northwestern Pacific exceeds one third of total global typhoons. China, located on the west of the northwestern Pacific, is one of the contries suffering the most severe damage from typhoon activities. Kuroshio is a well-known western boundary current. For most of typhoons landed on east China, Kuroshio / warm eddy is a boundary area that typhoons have to cross over before their landing, and is one of key factors to influence their landing situations. Different from the open ocean, Kuroshio has strong advection and baroclinic pressure gradient, and therefore, the dynamic response of the Kuroshio relies on not only typhoon energy input, but also its advection and pressure gradient terms. Meanwhile, thermal response of the Kuroshio is also influenced by its complex dynamica response. Influence of warm eddies on a typhoon is similar to the Kuroshio. The present forcast skill on typhoons, especially on typhoon strength, doesn't fulfil government's expectation. One of the most important factors is lacking of a clear understanding of typhoon-ocean interactions. Therefore, the study of the air-sea interaction between typhoon and Kuroshio plays an important role on improving typhoons' simulating and forcasting skills.

西北太平洋台风每年发生的频次超过全球台风总数的1/3，我国地处西北太平洋西侧，是世界上受台风危害最严重的国家之一。黑潮是西北太平洋著名的西边界流，对于大多数产生于西北太平洋热带洋面的台风来说，黑潮及其周边暖涡区是它们登陆前的必经之路，也是影响台风最后登陆状态的重要因素。与大洋对台风响应不同，黑潮本身存在强劲的平流和斜压梯度，使得黑潮对台风的动力响应不仅取决于台风的动量输入，还取决于台风扰动下黑潮平流和斜压梯度的变化。同时，黑潮动力响应的复杂性也决定了其热力响应的复杂性。暖涡对台风的影响与黑潮相似，由于数量多，分布广，其作用依然不可小视。目前我国对台风的预报，特别是对台风强度的预报水平与国家防灾减灾的的迫切需求还不相适应，其中一个重要的原因是对台风-海洋相互作用的机理认识不足。因此，针对西北太平洋台风和黑潮/暖涡相互影响机制的研究对提高台风登陆状态的模拟和预报具有重要的意义。

我国是世界上受台风危害最严重的国家之一，因此台风研究和预报是国家防灾减灾的迫切要求。针对西北太平洋台风和黑潮/涡旋相互影响机制的研究对于提高台风登陆状态的模拟和预报技巧具有重大的意义。本研究揭示了黑潮的变化特征，统计了台风和黑潮 / 暖涡的相互影响和相互响应特征，进一步利用高分辨率的海气耦合模式进行能量收支分析，通过敏感性试验，系统分析不同类型台风与不同状态的黑潮 / 暖涡相互影响和相互响应机制，发展了一套基于人工智能神经网络的台风模式SST参数化方案，克服了使用卫星SST作为台风模式海洋边界条件的局限性。针对2015-1016年17个台风的回报试验，提高了台风模拟精度大约20%。该参数化方案目前在中国气象局台风预报系统内测平台测试，有望被业务化台风预报系统采纳。