Differences in the Indonesian seaway in a coupled climate model and their relevance to Pliocene climate and El Niño
Differences in the Indonesian seaway in a coupled climate model and their relevance to Pliocene climate and El Niño
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DOI：
10.1029/2008pa001678
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发表时间：
2009-03
期刊：
影响因子：
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通讯作者：
M. Jochum;B. Fox‐Kemper;P. Molnar;C. Shields
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文献类型：
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作者：
M. Jochum;B. Fox‐Kemper;P. Molnar;C. Shields
[1]一个完全耦合的大气环流模型被用来调查的假设，在上新世时期在印度尼西亚海域的构造变化修改了印度-太平洋的热量输送，从而增加了纬向海表面温度梯度在赤道太平洋的大，目前的幅度。我们发现，扩大印尼海道移动新几内亚的北方尖端的赤道以南，导致南太平洋沃茨流入印度洋的增加，但由于跨赤道流的潜在涡度约束，它也导致减少北太平洋沃茨的流入和总的印尼通流运输。减少的通流是相匹配的增加东输送的温暖和新鲜的北太平洋表面沃茨沿着赤道到赤道太平洋中部。因此，热带辐合带更靠近赤道，而西太平洋暖池则比目前的情况向东扩展得更远。这减少了厄尔尼诺-南方涛动（ENSO）的延迟振荡成分，并增强了随机扰动的作用。因此，随着印度尼西亚的海道变得更加开阔，ENSO变得更弱和更不规则。
[1] A fully coupled general circulation model is used to investigate the hypothesis that during Pliocene times tectonic changes in the Indonesian seas modified the Indo-Pacific heat transport and thus increased the zonal sea surface temperature gradient in the equatorial Pacific to its large, current magnitude. We find that widening the Indonesian seaway by moving the northern tip of New Guinea south of the equator leads to an increased inflow of South Pacific waters into the Indian Ocean, but because of potential vorticity constraints on cross-equatorial flow it also leads to reductions in both the inflow of North Pacific waters and the total Indonesian throughflow transport. The reduced throughflow is matched by increased eastward transport of warm and fresh North Pacific surface waters along the equator to the central equatorial Pacific. As a result, the Intertropical Convergence Zone lies closer to the equator and the western Pacific Warm Pool expands farther east than for present-day conditions. This reduces the delayed oscillator component of El Nino–Southern Oscillation (ENSO) and enhances the role of stochastic perturbations. Thus, with a more open Indonesian seaway, ENSO becomes weaker and more irregular.