Model assessment of decadal variability and trends in the tropical Pacific Ocean
Model assessment of decadal variability and trends in the tropical Pacific Ocean
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DOI：
10.1175/1520-0442(1998)011
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发表时间：
1998-09
影响因子：
4.9
通讯作者：
T. Knutson;S. Manabe
中科院分区：
文献类型：
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作者：
T. Knutson;S. Manabe
摘要本文利用全球海气耦合模式研究了近世纪太平洋海温的年代际变化和趋势。模式中内部产生的年代际（>7年）变率的主导模态在模式和振幅方面与观测到的年代际变率相似。在模式中，热带风场和海洋热含量在年代际尺度和ENSO时间尺度上的分布和时间演变规律相似，表明年代际变率具有与ENSO时间尺度相似的“延迟振荡”机制。热含量异常向西的位相传播相对较慢，年代际变化的中心距赤道稍远（12° vs9 °N）。在模式中，在年代际变率的热带暖位相期间，中纬度北太平洋的冷SST异常主要是由海洋平流异常引起的。一个指数的观测SST在一个广泛的三角形区域的热带气旋。
Abstract In this report, global coupled ocean–atmosphere models are used to explore possible mechanisms for observed decadal variability and trends in Pacific Ocean SSTs over the past century. The leading mode of internally generated decadal (>7 yr) variability in the model resembles the observed decadal variability in terms of pattern and amplitude. In the model, the pattern and time evolution of tropical winds and oceanic heat content are similar for the decadal and ENSO timescales, suggesting that the decadal variability has a similar “delayed oscillator” mechanism to that on the ENSO timescale. The westward phase propagation of the heat content anomalies, however, is slower and centered slightly farther from the equator (∼12° vs 9°N) for the decadal variability. Cool SST anomalies in the midlatitude North Pacific during the warm tropical phase of the decadal variability are induced in the model largely by oceanic advection anomalies. An index of observed SST over a broad triangular region of the tropi...