Regime Shifts in the Northern Hemisphere SST Field: Revisited in Relation to Tropical Variations
Regime Shifts in the Northern Hemisphere SST Field: Revisited in Relation to Tropical Variations
复制标题
北半球海温场的变化：重新审视与热带变化的关系
DOI：
10.2151/jmsj.81.415
复制
发表时间：
2003
影响因子：
3.1
通讯作者：
K. Hanawa
中科院分区：
文献类型：
--
作者：
S. Yasunaka;K. Hanawa
从1910年代到1990年代，研究了作者先前发现的北半球海温变化与热带海温的关系。结果表明，被认为是厄尔尼诺/南方涛动的良好指示器的Nino 3.4区的海温随着海温的变化呈现出一致的变化。基于Nino 3.4海温的回归图显示了典型的厄尔尼诺现象。从原始海温场中减去与Nino 3.4海温线性相关的变化，得到剩余海温场。经验正交函数(EOF)分析表明，仅限于中高纬度北太平洋的残差场的主要变化模式被称为北太平洋模式。另一种主要的变化模式对应于北极涛动。在剩余海温场中可以检测到所有的区域漂移。大部分海温变化(1925/26年、1945/46年、1957/58年、1970/71年和1976/77年)与上述两种EOF模式和Nino 3.4海温的变化同时发生，而1988/的海温变化与Nino 3.4海温的变化无关。这表明这种变化可以分为两类：一类与热带太平洋和印度洋的变化密切相关，另一类与热带变化无关。
The regime shifts previously identified by the authors over the Northern Hemisphere during the period from the 1910s to the 1990s is investigated in relationship with tropical sea surface temperature (SST) variation. It is found that SST of the Nino 3.4 region, which is known to be a good indicator of El Nino/Southern Oscillation, shows coherent changes with the regime shifts. The regression maps based on Nino 3.4 SST show typical El Nino condition. By subtracting the variations linearly correlated with Nino 3.4 SST from the raw SST field, the residual SST field is obtained. An empirical orthogonal function (EOF) analysis shows a dominant mode of variations in the residual field that is confined to the mid- and high-latitude North Pacific, which is known as the North Pacific mode. Another dominant mode of variation corresponds to the Arctic Oscillation. All the regime shifts are detectable in the residual SST field. Most of the regime shifts (the 1925/26, 1945/46, 1957/58, 1970/71, and 1976/77 shifts) took place concurrently with the two aforementioned EOF modes, and changes in the Nino 3.4 SST, while the 1988/89 shift was not associated with the Nino 3.4 SST changes. This indicates that the regime shifts can be divided into two groups: one is closely linked with the tropical Pacific and the Indian Ocean variations, and the other is independent of these tropical variations.