热带不稳定波的年际变化及其与ENSO的关系

摘要

使用最优插值的1/4°逐日海温再分析资料(NOAA OISST V2.0)逐日海温资料研究了热带不稳定波(TIWs)的年际变化特征及其与厄尔尼诺与南方涛动(ENSO)的关系。结果表明： TIWs一般在每年的5~7月开始出现，在11~12月末或次年1月末消亡。TIWs和ENSO存在负相关关系，即在ENSO暖位相年(厄尔尼诺年)， TIWs强度减弱；在ENSO的冷位相年(拉尼娜年)， TIWs强度增强。进一步分析表明，在TIWs活跃的6~12月，其与ENSO存在很好的负相关，且相关性在12月最好。对 TIWs 和尼诺3.4区指数(NINO 3.4)海表面温度距平(SSTA)进行超前滞后相关分析，发现在 TIWs超前ENSO 2~3个月时两者的相关性最显著，这意味着TIWs可能对ENSO循环具有调控作用。%Using NOAA OISST V2.0 reanalysis data, we studied the interannual variability of tropical instability waves (TIWs). Results show that:TIWs usually appear during May and July and are absent in December or next January. A negative relationship is identified between the year-to-year variations of TIWs activity and that of ENSO intensity, with stronger TIWs activity in La Nina years and weaker TIWs activity in El Niño years. The negative relationship is more evident in the active period of TIWs during June and December, and the biggest correlation coefficient is in December. Applying lead/lag correlation analysis on TIWs index and NINO 3.4 SSTA, the results suggest that the maximum correlation coefficient appears when TIWs index leads the ENSO index by 2~3 months, which indicate that the TIWs may modulate the cycle of the ENSO.