西北太平洋季风槽年际和年代际变化成因及其对台风活动的影响研究

Typhoon is one of serious meteorological disasers in China, which brought huge economic loss and serious casualties in coastal provinces of Southeast China and Taiwan Province each year.For preventing and reducing this natural disaster, the seasonal prediction of tropical cyclones activities and landfalling typhoons over the western North Pacific (WNP) needs to be carried out urgently in China. Since most geneses and moving tracks of tropical cyclones and typhoons (TCs) over the WNP are closely related to the monsoon trough, thus, this research project will analyze and reveal the characteristics of interannual and interdecadal variations of the monsoon trough over the WNP during June to October, based on the NCRP/NCAR、ERA-40 and, JRA-25 reanalysis data and the JTWC observational data of tropical cyclones. Moreover, the effects of the interannual and interdecadal variabilities of the SST in the tropical central and eastern Pacific, the subsurface temperature in the tropical western Pacific and the thermal condition of the tropical Indian Ocean on the monsoon trough over the WNP during June to October will be analyzed and revealed from both reanalysis data and numerical simulations. And the influence and its process of cross-equatorial flow during June to October on the interannual and interdecadal variations of location and intensity of the monsoon trough over the WNP will be also analyzed and revealed from the reanalysis data. Besides, the effect and its mechanism of the intreannual and interdecadal variations of the monsoon trough on typhoons activity over the WNP will be studied further by using the dynamical theory and numerical simulations. The project would publish 10-12 papers, including 6 papers in SCI Journals.

台风是我国主要气象灾害之一，它给我国东南沿海和台湾省带来巨大的经济损失和严重的人员伤亡，为了防灾减灾，当前国家亟需开展西北太平洋台风活动和登陆我国台风的季度预测，而西北太平洋大部分热带气旋和台风(TCs)生成和路径与季风槽有关。为此，本项目利用NCEP/NCAR，ERA-40和JRA-25等再分析资料和JTWC热带气旋观测资料分析并揭示6-10月西北太平洋季风槽位置和强度的年际和年代际变化特征；并且，从再分析资料和数值模拟来分析和揭示热带东、中太平洋SST、热带西太平洋次表层海温和热带印度洋热力的年际和年代际变异对6-10月西北太平洋季风槽的影响及其过程；同时还分析并揭示6-10月跨赤道气流变化对西北太平洋季风槽变化的影响及过程；此外，本研究还从动力理论和数值模拟来研究西北太平洋季风槽年际和年代际变化对台风活动影响及其机理。本项目将发表论文10-12篇，其中SCI收录刊物上发表6篇。

本项目利用NCEP/NCAR，ERA-40和JRA-25等再分析资料和JTWC热带气旋观测资料分析并揭示了初夏以及台风季西北太平洋季风槽年际和年代际变化及其对西北太平洋热带气旋生成的影响及其过程；同时揭示了西太平洋暖池对西北太平洋季风槽和热带气旋生成年际和年代际变化的热力影响及其过程和机理；并且，项目还揭示了东亚冬、夏季风对南海热带气旋生成的影响及其利于热带气旋生成的环流型；此外，本研究还应用全球海-气耦合数值模式对西北太平洋热带气旋生成进行了高分辨率数值模拟。本研究在台风气候动力学理论上具有明显的创新，不仅在揭示西北太平洋季风槽的变化对热带气旋的年际和年代际变化影响机理具有重要科学意义，而且对于解释我国旱涝等现象和灾害的发生也有潜在的应用意义。