Local origins of interdecadal Pacific variability in the tropical and North Pacific Ocean: evidence from a comparative study of coral oxygen isotope records
Local origins of interdecadal Pacific variability in the tropical and North Pacific Ocean: evidence from a comparative study of coral oxygen isotope records
复制标题
DOI：
10.1007/s00367-014-0365-3
复制
发表时间：
2014-02
影响因子：
2.1
通讯作者：
W. Deng;G. Wei
中科院分区：
文献类型：
--
作者：
W. Deng;G. Wei
太平洋年代际变率（IPV）在热带和中纬度太平洋都是普遍存在的，对泛太平洋盆地的地面气候有着广泛的影响。这种变异性由气候代用指标记录下来，如保存在珊瑚中的地球化学参数。然而，IPV的起源仍然不确定。为了阐明这一点，研究了热带太平洋瑙鲁岛和中纬度北太平洋南海珊瑚δ 18 O长记录的年代际变化。瑙鲁岛（热带太平洋）δ 18 O序列的年代际波动与NINO3.4指数的年代际波动有较好的相关性（r=-0.30，n = 96，p=0.0015），但与太平洋年代际振荡（PDO）指数的年代际波动无相关性（r=-0.17，n = 96，p=0.05）。而南海（西北太平洋）δ 18 O时间序列与PDO指数存在协变关系（r=-0.30，n = 156，p=0.0007），与NINO3.4指数在年代际时间尺度上存在反相关系（r= 0.04，n =156，p=0.31）。对珊瑚生长区以外发生的过程的年代际变化的影响一般较弱。因此，结果并不支持热带起源的IPV，但表明，年代际变化在热带太平洋和北太平洋主要源于本地耦合的海洋-大气过程在这些地区。结果还表明，热带-外热带相互作用在1920 - 1940年的IPV中起了一定的作用，这表明IPV是一个复杂的气候现象，涉及多种强迫机制。
Interdecadal Pacific variability (IPV) is commonly observed in both the tropical and mid-latitude Pacific Ocean, and has a widespread influence on surface climate in the Pan-Pacific Basin. This variability is recorded by climate proxies such as geochemical parameters preserved in corals. However, the origins of IPV remain uncertain. To shed light on this, interdecadal variations in two long coral δ18O records from Nauru Island and the South China Sea (SCS), respectively located in the tropical Pacific and the mid-latitude North Pacific Ocean, were investigated. The interdecadal fluctuations in the δ18O series from Nauru Island (tropical Pacific) match those of the NINO3.4 index reasonably well (r=–0.30,n=96, p=0.0015), but are not correlated with those of the Pacific decadal oscillation (PDO) index (r=–0.17,n=96, p=0.05). The δ18O time series from the SCS (northwestern Pacific), by contrast, co-vary with the PDO index (r=–0.30,n=156, p=0.0007), but are out of phase with the NINO3.4 index at the interdecadal timescale (r=0.04,n=156, p=0.31). The impact on the interdecadal variability of processes occurring outside the growth region of corals is generally weak. The results thus do not support a tropical origin of IPV, but demonstrate that the interdecadal variability in the tropical Pacific and the North Pacific originates predominantly from local coupled ocean–atmosphere processes within these regions. The results also suggest that tropical–extratropical interactions played a role in IPV between 1920 and 1940, which indicates that IPV is a complex climatic phenomenon that involves multiple forcing mechanisms.