South Pacific origin of the decadal ENSO-like variation as simulated by a coupled GCM
South Pacific origin of the decadal ENSO-like variation as simulated by a coupled GCM
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DOI：
10.1029/2003gl018649
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发表时间：
2003-12-18
影响因子：
5.2
通讯作者：
Yamagata, T
中科院分区：
文献类型：
--
作者：
Luo, JJ;Masson, S;Yamagata, T
利用ECHAM 4/OPA/OASIS耦合模式的200年资料，对ENSO年代际（7-35年）变化的南太平洋起源假说进行了研究。伴随着热带太平洋暖（冷）海温的年代际异常，南太平洋出现了一个向东南-西北方向倾斜的异常气旋（反气旋）环流。这导致沿异常环流东北边缘的异常向上（向下）的埃克曼泵送沿着，从而使那里的海洋温跃层变浅（加深）。这种外部热含量来源往往在十年时间尺度上缓慢地释放/补充热带海洋。上述结果与Luo和Yamagata [2001]的观测研究结果一致。此外，模式还模拟了全球陆面温度与年代际Nino 3 SST之间的滞后相关。尽管存在模式偏差，这表明了一个潜在的预测技术的全球变暖的基础上ENSO样的年代际变化。
The hypothesis of the South Pacific origin of the decadal (7-35 years) ENSO-like variation is investigated based on 200-year outputs of the ECHAM4/OPA/OASIS coupled GCM. Associated with the decadal warm (cold) SST anomalies in the tropical Pacific, an anomalous cyclonic (anticyclonic) circulation, which is tilted in a southeast-northwest direction, appears in the South Pacific. This results in anomalous upward (downward) Ekman pumping along the northeastern edge of the anomalous circulation and, hence, shallowing (deepening) the oceanic thermocline there. Such an external source of heat content tends to slowly discharge/recharge the tropical ocean on the decadal timescale. The above result is consistent with the observational study of Luo and Yamagata [2001]. Besides, the model reproduces amazingly a high lagged-correlation between the global land surface temperature and the decadal Nino3 SST. Despite the model biases, this suggests a potential prediction skill of the global warming based on the ENSO-like decadal variation.