摘要
采用SODA海面高度(SSH)数据研究热带太平洋海域的年代际变化。结果表明,热带太平洋海面高度场存在与太平洋年代际涛动(PDO)时间过程基本一致的年代际变化,但是SSH异常的空间分布与SST异常的是不同的。热带海域年代际变化的典型空间分布:海面高度异常在热带海域存在东西方向的反向变化,在西太平洋只有1个变化中心,而在东太平洋形成2个对称于赤道的变化中心。热带太平洋海面高度的年代际变化有2个基本周期:13 a左右的周期和30 a以上时间尺度的气候转型周期。其中13 a周期的年代际变化与ENSO年际过程无关,是热带太平洋年代际变化的重要组成部分。由于数据时间长度的限制,气候转型的时间尺度还不明确,也不清楚其是否有明显的周期性。比较热带东西太平洋年代际变化的特征,可以发现以气候转型期的年代际信号在东西太平洋几乎是同时发生的,而13 a左右周期的年代际信号在赤道附近却存在自西向东方向的传播。
In this paper, the simple ocean data assimilation （SODA） sea surface height （SSH） dataset is used to study the decadal variability in the tropical Pacific （DVIP）. It is shown from the study results that the decadal variations in SSH in the tropical Pacific are basically consistent with those in the Pacific decadal oscillation （PDO） index, and the spatial distributions of SSH anomaly are different from those of SST anomaly. The typical spatical distributions of DVIP are that the variations in SSH anomaly in the eastern tropical Pacific are reversed to those in the western one, there is only one variation center in the western Pacific, and there are two variation centers symmetric about the equator. The SSH DVIP has two basic periods, a 13-year period and a climatic transformation period with a time scale of over 30 years. Among them, the 13-year period variabbility is independent of the ENSO interannual variability, and is an important component of DVIP. The time scale of variations with the second period is still uncertain due to the limitation of data time length. It is shown from the comparison between the decadal variations in the eastern and western tropical Pacific that the decadal variations with a climatic transformation period occurred almost simultaneously in the eastern and western tropical Pacific, but the decadal variations with a 13-year period in the tropical Pacific propagated eastward.
出处
《海洋科学进展》
CAS
CSCD
北大核心
2008年第2期163-170,共8页
Advances in Marine Science
基金
国家自然科学基金重点项目--北极环极边界流的结构及其对气候的变化贡献的研究(40631006)
关键词
热带太平洋
海面高度
年代际变化
EOF分解
tropical Pacific
sea surface height
decadal variability
empirical orthogonal function （EOF）decomposition
