【作者】 刘通易；

【导师】 吴立广；

【作者基本信息】 南京信息工程大学 ， 气象学， 2012， 硕士

【摘要】 本研究利用中国气象局逐日台站降水资料和上海台风研究所热带气旋最佳路径数据集等资料,采用客观天气图分析方法(OSAT)分离热带气旋降水,讨论了1965-2010年7-9月影响我国的热带气旋降水的时空分布特征及长期变化趋势,并就热带气旋盛行路径的偏移及影响我国水汽输送的变化两个因子如何影响我国热带气旋降水的趋势变化进行了分析。将利用OSAT分离出的降水与风云卫星资料的降水估计产品进行了对比,结果表明：对于不同强度的热带气旋,OSAT方法都能够十分有效的识别热带气旋降水。对于热带气旋降水的气候学时空分布特征,研究发现,7-9月热带气旋降水主要影响中国东部和南部,虽然中国东北以及中西部地区也受到热带气旋降水的影响,但其影响很小,热带气旋盛季平均的热带气旋降水呈现由沿海向内陆,由东南向西北递减的分布形态。自1965年以来,7-9月影响中国的热带气旋降水呈现华东及东南沿海增多,华南沿海、海南岛以及西南地区减少的变化趋势。进一步对影响热带气旋趋势变化的机制分析发现,一方面西北太平洋副高加强西伸,使得水汽难以输送至我国长江以北地区,导致我国东部地区上空的水汽辐合增强；另一方面热带气旋的引导气流发生变化,使得热带气旋盛行路径由南海向东亚沿岸偏移,我国华东地区热带气旋影响增加,这两个因子的共同作用致使影响中国的热带气旋降水发生变化。这种热带气旋降水的长期变化趋势可能与全球气候变暖有关。更多还原

【Abstract】 The tropical cyclone precipitation is partitioned from the station observations in China using the Objective Synoptic Analysis Technique (OSAT). With daily station precipitation and tropical cyclone track datasets and so on, the trend of July-September tropical cyclone precipitation in China during1965-2010, the climate characteristics of tropical cyclone precipitation and the associated mechanisms are examined in this study. Results indicate that OSAT is capable of distinguishing simultaneous tropical cyclone precipitation. Tropical cyclone rainfall mainly affected the eastern and southeastern half of China during July-September, it gradually decreases from southeast coastal regions to northwest regions. An increasing trend in tropical cyclone precipitation is found in east China and southeast coastal areas, with a decreasing trend in south China coastal areas, Hainan Island and southwest China over the period1965-2010. The strengthening and westward extension of the Western Northern Pacific subtropical high makes strong moisture convergence in east China, and the change of large-scale steering flows causes shifts in prevailing typhoon tracks from the South China Sea to East Asian coast, leading to changes in the summer tropical cyclone precipitation in China since1965. The long-term trend of tropical cyclone precipitation may be associated with the undergoing global warming.更多还原