Liu Jingjing, Tian Jun, Liu Zhonghui, Herbert Timothy D, Fedorov Alexey V, Lyle Mitch
State Key Laboratory of Marine Geology, Tongji University, Shanghai 200092, China.
Department of Earth Sciences, The University of Hong Kong, Hong Kong, China.
Sci Adv. 2019 Apr 3;5(4):eaau6060. doi: 10.1126/sciadv.aau6060. eCollection 2019 Apr.
The timing and mechanisms of the eastern equatorial Pacific (EEP) cold tongue development, a salient feature of the tropical ocean, are intensely debated on geological time scales. Here, we reconstruct cold tongue evolution over the past 8 million years by computing changes in temperature gradient between the cold tongue and eastern Pacific warm pool. Results indicate that the cold tongue remained very weak between 8 and 4.3 million years ago, implying much weaker zonal temperature gradients prevailing during the late Miocene-Pliocene, but then underwent gradual intensification with apparently increasing sensitivity of the cold tongue to extratropical temperature changes. Our results reveal that the EEP cold tongue intensification was mainly controlled by extratropical climate.
热带海洋的一个显著特征——赤道东太平洋冷舌的形成时间和机制，在地质时间尺度上一直存在激烈争论。在此，我们通过计算冷舌与东太平洋暖池之间的温度梯度变化，重建了过去800万年冷舌的演变过程。结果表明，在800万至430万年前，冷舌一直非常微弱，这意味着在中新世晚期至上新世期间，纬向温度梯度要弱得多，但随后冷舌逐渐增强，对温带温度变化的敏感性明显增加。我们的结果表明，赤道东太平洋冷舌的增强主要受温带气候控制。
