40-60 day oscillations in the western tropical Pacific : results from an eddy-resolving global ocean model
40-60 day oscillations in the western tropical Pacific : results from an eddy-resolving global ocean model
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DOI：
10.1029/92gl01640
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发表时间：
1992-07
影响因子：
5.2
通讯作者：
R. Ponte;D. Gutzler
中科院分区：
文献类型：
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作者：
R. Ponte;D. Gutzler
对 Semtner 和 Chervin [1992] 涡旋解析大气环流模型结果的初步分析揭示了西热带太平洋近地表层存在 40-60 天的高能振荡。这些振荡在以北纬 10°和南纬 10° 为中心的日界线以西的纬度带中，经向速度信号最强（最大振幅约为 10-20 cm s−1）。 40-60 天的扰动在 10°N 处的纬向波长约为 700 km，在 10°S 处的纬向波长约为 1000 km，并以 15-20 cm/s 的速度显示出明显的向西相位传播。向东（但较慢）的能量传播也很明显。模型中的振荡是海洋不稳定过程的结果，而不是对与大气中马登-朱利安振荡相关的风应力异常的直接响应。印度和大西洋盆地也存在 40-60 天的能量增强，这表明 40-60 天的时间尺度是热带海洋变化的首选尺度。
Preliminary analyses of results from the Semtner and Chervin [1992] eddy-resolving general circulation model reveal the presence of energetic 40–60 day oscillations in the near-surface layers of the western tropical Pacific. These oscillations have the strongest signal in meridional velocity (maximum amplitudes on the order of 10–20 cm s−1), in latitudinal bands west of the dateline centered at approximately 10°N and 10°S. The 40–60 day disturbances have zonal wavelengths of approximately 700 km at 10°N and 1000 km at 10°S, and show clear westward phase propagation at speeds of order 15–20 cm/s. Eastward (but slower) energy propagation is also apparent. The oscillations in the model are a result of oceanic instability processes and not a direct response to wind stress anomalies associated with the Madden-Julian oscillation in the atmosphere. Enhanced energy at 40–60 days is also present in the Indian and Atlantic basins, suggesting that the 40–60 day time scale is a preferred scale for variability in the tropical oceans.