摘要
根据西北太平洋56年(1949—2004年)热带气旋系列资料,分析了不同级别的热带气旋频数多年变化的统计特征及其与太平洋海表温度(SST)的关系。结果表明:西北太平洋热带气旋频数主要的变化特征是年际和年代际变化,不同等级的热带气旋频数变化特征存在差异,但就变化趋势而言随时间减少,均无明显因全球增暖导致的热带气旋增加的现象。对不同海区分别讨论SST对热带气旋的影响,从存在的超前滞后相关发现赤道东太平洋SST负异常会引起更多的热带气旋频数,而且强度越大的热带气旋受到海温的影响越早;更多的热带气旋频数又会引起西北太平洋的SST负异常,热带气旋强度越大产生负异常的周期越短;北太平洋中部的SST与热带气旋的频数存在较好的正相关关系。这些关系体现了热带气旋强涡旋风场导致局地海洋上层混合作用和太平洋海气耦合经向模态对热带气旋的影响。
Using the data of Tropical Cyclones （TCs） series for the 56-yr period of 1949--2004, we studied the statistical characteristics of the multi-year variation of the frequency of TCs activity over the western North Pacific and the relationship with sea surface temperature （SST）. The results show that the frequency of TCs activity over the area has interannual and interdecadal variability, which differs with the intensity of TCs but tends to decrease with time and TCs do not increase significantly due to global warming. Three areas are identified in this study to discuss the influence of SST. The results show that the increase of TCs frequency is caused by negative SST anomaly in the equatorial eastern Pacific. The positive anomaly of TCs frequency will result in negative SST anomaly in the western North Pacific based on an existing lead-lag correlation. The more severe the TCs, the earlier they are influenced by SST and large frequency of TCs will in turn result in negative SST anomaly in western North Pacific. The stronger the TCs, the shorter the period for which they produce negative anomaly. The SST of central North Pacific is much positively correlated with the frequency of TCs, which shows that an intense vortex wind field of TCs can result in local mixing in the upper layers of the ocean and the Pacific Meridional Mode （PMM） for air-sea coupling can affect TCs.
出处
《热带气象学报》
CSCD
北大核心
2009年第3期273-280,共8页
Journal of Tropical Meteorology
基金
国家自然科学基金项目(No.40675051)
国家973项目(2006CB403600)共同资助
关键词
气候学
热带气旋:
相关分析
变化特征
海表温度
climatology
tropical cyclones
analysis of correlation
variational characteristics： sea surface temperature
