印度洋-太平洋暖池的变异研究

THE VARIATION OF THE INDO-PACIFIC WARM POOL

为了研究在何种时间尺度上定义研究印度洋-太平洋暖池(简称印-太暖池)更有意义,本文中应用功率谱等统计学方法,对印-太暖池的季节、年际及年代际变化特征进行了分析。结果表明,印-太暖池、东印度洋暖池(简称东印暖池)在季节变化上表现为单峰结构,而西太平洋暖池(简称西太暖池)则为双峰结构;在年际变化上印-太暖池和西太暖池表现出很强的3—6年变化周期,东印暖池则存在准两年的振荡周期;印-太暖池还存在10年以上的年代际周期振荡,特别是70年代中后期的年代际突变明显,而东印暖池的这种变化更为明显。由此可知印-太暖池的年代际变化与东印暖池、西太暖池年代际变化较为相似,季节和年际变化颇为不同,所以,在研究年代际尺度的问题上,定义并研究印-太暖池的意义更大,而在研究年际、季节尺度上的问题时东印暖池、西太暖池应分而视之。

To determine which time scale is proper for defining meaningful warm pools in eastern Indian Ocean and Western Pacific, the authors studied statistically the seasonal, interannual and decadal variations of them. Results show that in seasonal scale, the variation of the Indo-Pacific Warm Pool （I-PWP） and the Eastern Indian Ocean Warm Pool （EIWP） shows an obvious one-peak pattern, and two peaks in that of the Western Pacific Warm Pool （WPWP）. In annual scale, both I-PWP and WPWP show a 3- to 6-year oscillation, and quasi-biennial oscillation for EIWP. In decadal scale, the three warm pools experienced quick change that is very clear in middle to late 1970s, especially for the EIWP. Therefore, the decadal variation of the I-PWP is similar to that of EIWP and WPWP, but seasonal and interannual ones are different from those of the EIWP and WPWP. It is suggested that the study on the I-PWP should be more meaningful on decadal scale, whereas for EIWP and WPWP, seasonal and interannual scales are better and can be treated separately.