南海热带气旋突然加强的机理及预报方法研究

High frequency of rapid intensification of tropical cyclones (TCs)is found in the South China Sea (SCS), and these TCs are generally shortly lived. On the other ahnd, complex atmospheric conditions and unique air-sea interactions make the mechanisms for the rapid intensification of TCs in the SCS complicated and diverse. Therefore, there exists much difficulty in predicting the rapid intensification of the SCS TCs, which may cause serious disasters and losses due to the inaccurate forecasts and warning. At present, the inderstanding of the mechanisms for the SCS TC rapid intensification and quantitative predictive indices are lack. In this study, we will use climatological analysis,diagnoses of regionally enhanced satellite imagery, and numerical simulations with a air-sea-land coupled model to reveal the physical mechanisms for TC rapid intensification in the SCS, obtaining the corresponding dynamic models and exploring the prediction indices of the rapid intensification. It is expected that the associated results will provide scientific evidence for improving the forecast ability of TC intensity in the SCS.

我国南海是热带气旋突然增强多发的海域，通常南海热带气旋生命史短；另一方面，复杂大气环境条件和独特的海气相互作用使得影响南海热带气旋突然增强的因素和机理复杂多变。因此，针对南海热带气旋突然增强的预报难度大，预报预警不及时将可能导致严重的灾害损失。目前针对南海台风突然增强的物理机制的研究和定量化预报指标仍较缺乏。本课题将通过气候特征分析，区域增强扫描卫星云图演变特征诊断，以及海-陆-气耦合模式数值试验从不同角度揭示南海热带气旋突然增强的物理机制，建立南海台风突然增强的物理模型，提炼出相关预报指标，为提高台风强度预报能力提供科学依据。

我国南海是热带气旋突然增强多发的海域，预警的不及时可能会对大陆地区带来严重的经济财产损失。由于复杂的大气环境条件和海气相互作用使得此类系统突然增强的物理机制复杂多变，尚不完善的机理研究增加了预报的不确定性和难度，是热带气旋强度预报中亟待解决的问题。本项目运用观测资料，分析了南海热带气旋迅速加强的气候特征，研究了不同的环境场因子对南海热带气旋迅速加强的影响，并根据诊断结果建立了适用于南海地区热带气旋迅速加强的统计预报模型。利用高分辨率数值模式，开展了针对南海区域热带气旋的FY-2F红外辐射资料的直接同化试验、近岸雷达资料同化试验以及物理参数化方案适用性的试验，对发生快速增强的热带气旋的内核结构、相关微物理过程的演变以及模式可预报性进行了深入的探讨。