赤道东太平洋海温与南海热带风暴频数的相关关系

THE CORRELATION BETWEEN SST FOR EQUATORIAL EASTERN PACIFIC AND FREQUENCY OF OCCURRENCE FOR TROPICAL STORMS IN THE SOUTH CHINA SEA

根据1949—1987年的赤道东太平洋海温和热带气旋资料,分别分析了在南海形成的热带风暴频数和影响南海的热带风暴频数(包括南海形成和由西太平洋移入南海)与赤道东太平洋海温的时滞相关关系,统计了海温暖期(El NinoA)和冷期(反El Nino)与以上两类热带风暴频数的联系。初步结果表明,赤道东太平洋海温与影响南海的热带风暴频数之间,同期为负相关(—0.30)风暴晚于海温17个月时出现正相关极大值(+0.29);赤道东太平洋海温与南海形成的热带风暴频数之间的相关有所不同,最大相关(+0.38)出现在热带风暴晚于海温12个月之时,同期相关关系不明显。对El Nino和反El Nino时段的统计结果也证实了这些相关特点,这些结果对于南海热带风暴长期趋势预报可有一定参考价值。

Using the data of SST and tropical storms for 1949-1987,the time-lag correlation is analysed between the frequency of occurrence for the tropical storms generating over or affecting the South China Sea(including those generating there and coming from the western Pacific) and the SST over the equatorial eastern Pacific.Statistics is obtained for the relat ion between the warm (El Nino) and cold (anti- El Nino) episodes and the two categories of tropical storms defined above.For the correlation between the SST and the frequency of occurrence of the storms affecting the sea, the preliminary result shows it tc be negative (-0.30) when they are in the same period, and maximum positive (+0.29) when the latter occur 17 months late than the former. In comparison, the correlation is indicated to be the maximum (+0.38) for the SST and the storms generating in the South China Sea when the latter appear 12 months late than the former, and insignificant when they are in the period. Statistics of the episodes of El Nino and anti-El Nino also confirms the characteristics. The results here have some value of reference for the forecast of long-term tendency of tropical storm in the South China Sea.