From centennial to millennial oscillation of the thermohaline circulation
From centennial to millennial oscillation of the thermohaline circulation
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DOI：
10.1357/002224011795977635
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发表时间：
2010-09
影响因子：
0.5
通讯作者：
F. Sévellec;T. Huck;A. Verdière
中科院分区：
文献类型：
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作者：
F. Sévellec;T. Huck;A. Verdière
淡水通量强度被用来作为主要的控制参数，以不稳定的温盐环流（THC）：随着它的增加，经典的分歧的情况下，热稳定的稳定状态，千年振荡和盐稳定的稳定状态再现在一个二维带状平均的海洋模式在混合边界条件。这两个分叉都是通过全局分叉导致无限长的极限环而产生的。在这里，我们强调了百年振荡的重要性的不稳定性的热阶段的千年振荡，这可以被认为是一个前兆THC的崩溃。这表明，存在或不存在的百年振荡导致THC的崩溃时间尺度从几千年到只有几十年的巨大变化。这种分叉的情况下示出的耗散值是敏感的。
The freshwater flux intensity is used as the main control parameter to destabilize the ThermoHaline Circulation (THC): as it increases, the classical bifurcation scenario, thermal stable steady state, millennial oscillation and haline stable steady state are reproduced in a 2D zonally-averaged ocean model under mixed boundary conditions. Both bifurcations arise through global bifurcations leading to an infinite period of the limit cycle. Here we highlight a centennial oscillation important for the instability of the thermal phase of the millennial oscillation and which could be considered as a precursor to the collapse of the THC. It is suggested that the existence or the absence of this centennial oscillation leads to dramatic changes in the collapse time scale of the THC going from several thousand years to only a few decades. This bifurcation scenario is shown to be sensitive to the value of the dissipation.