El Niño in the Eocene greenhouse recorded by fossil bivalves and wood from Antarctica
El Niño in the Eocene greenhouse recorded by fossil bivalves and wood from Antarctica
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DOI：
10.1029/2011gl048635
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发表时间：
2011-08
影响因子：
5.2
通讯作者：
L. Ivany;T. Brey;M. Huber;Devin P. Buick;B. Schöne
中科院分区：
文献类型：
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作者：
L. Ivany;T. Brey;M. Huber;Devin P. Buick;B. Schöne
赤道太平洋海面温度、降水和海平面气压的准周期变化被称为厄尔尼诺-南方涛动(ENSO)，是全球气候年际变化的一种重要模式。流行的ENSO理论预测，在全球变暖的情况下，热带太平洋将坍塌成一种类似于所谓的永久厄尔尼诺现象的状态，赤道东太平洋优先变暖，温跃层变平，年际变化减少。如果预测正确，未来全球变暖将伴随着类似今天厄尔尼诺现象的持续状况的转变，这将对全球水文循环产生重大影响，并由此对社会经济和生态系统产生影响。然而，年际变化将如何受到影响，仍然存在很大的不确定性。在这里，我们提供了南极半岛双壳化石和共生浮木生长增量宽度的多年气候记录，这些记录显示出与ENSO一致的准两年和3-6年波段的显著变化，尽管早期始新世(∼50Mya)温室条件下全球平均温度∼比今天高出10度。一个耦合的气候模型表明，在始新世期间，ENSO信号和遥相关与这个地区很像今天。在这一明显变暖的时段内，ENSO变化的存在表明，在我们未来的温室世界中，强劲的年际变化将持续存在。
Quasi‐periodic variation in sea‐surface temperature, precipitation, and sea‐level pressure in the equatorial Pacific known as the El Niño – Southern Oscillation (ENSO) is an important mode of interannual variability in global climate. A collapse of the tropical Pacific onto a state resembling a so‐called ‘permanent El Niño’, with a preferentially warmed eastern equatorial Pacific, flatter thermocline, and reduced interannual variability, in a warmer world is predicted by prevailing ENSO theory. If correct, future warming will be accompanied by a shift toward persistent conditions resembling El Niño years today, with major implications for global hydrological cycles and consequent impacts on socioeconomic and ecological systems. However, much uncertainty remains about how interannual variability will be affected. Here, we present multi‐annual records of climate derived from growth increment widths in fossil bivalves and co‐occurring driftwood from the Antarctic peninsula that demonstrate significant variability in the quasi‐biennial and 3–6 year bands consistent with ENSO, despite early Eocene (∼50 Mya) greenhouse conditions with global average temperature ∼10 degrees higher than today. A coupled climate model suggests an ENSO signal and teleconnections to this region during the Eocene, much like today. The presence of ENSO variation during this markedly warmer interval argues for the persistence of robust interannual variability in our future greenhouse world.