Warm and wet conditions in the Arctic region during Eocene Thermal Maximum 2
Warm and wet conditions in the Arctic region during Eocene Thermal Maximum 2
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DOI：
10.1038/ngeo668
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发表时间：
2009
影响因子：
18.3
通讯作者：
A. Sluijs;Stefan Schouten;T. Donders;P. L. Schoon;U. Röhl;G. Reichart;F. Sangiorgi;Jung-Hyun Kim;J. Damsté;H. Brinkhuis
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文献类型：
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作者：
A. Sluijs;Stefan Schouten;T. Donders;P. L. Schoon;U. Röhl;G. Reichart;F. Sangiorgi;Jung-Hyun Kim;J. Damsté;H. Brinkhuis
几次突然和短暂的变暖，每次持续50，000到200，000年，打断了古新世晚期和始新世早期（5800万到5100万年前）时期的长期变暖。这些超高温事件，如始新世热最大值2（ETM 2）发生在大约5350万年前，与大气中CO2含量的快速增加有关。然而，大多数事件的影响只在当地记录。在这里，我们表明，根据TEX 86 '代理的估计，在ETM 2期间，北冰洋的海表温度上升了3-5摄氏度。甲藻化石表明，表层沃茨的淡水化和富营养化同时发生，导致透光层中的洋地黄。棕榈花粉的存在意味着北极大陆最冷的月平均温度不低于8摄氏度，这与模型模拟的冬季高温温度低于冰点的说法相矛盾。根据我们重建的温度和水文趋势，我们得出结论，温度和水文响应突然增加的大气CO2浓度是相似的ETM 2和更好地描述古新世始新世热最大，，55.5百万年前。
Several episodes of abrupt and transient warming, each lasting between 50,000 and 200,000 years, punctuated the long-term warming during the Late Palaeocene and Early Eocene (58 to 51 Myr ago) epochs,. These hyperthermal events, such as the Eocene Thermal Maximum 2 (ETM2) that took place about 53.5 Myr ago, are associated with rapid increases in atmospheric CO2content. However, the impacts of most events are documented only locally,. Here we show, on the basis of estimates from the TEX86′ proxy, that sea surface temperatures rose by 3–5∘C in the Arctic Ocean during the ETM2. Dinoflagellate fossils demonstrate a concomitant freshening and eutrophication of surface waters, which resulted in euxinia in the photic zone. The presence of palm pollen implies that coldest month mean temperatures over the Arctic land masses were no less than 8∘C, in contradiction of model simulations that suggest hyperthermal winter temperatures were below freezing. In light of our reconstructed temperature and hydrologic trends, we conclude that the temperature and hydrographic responses to abruptly increased atmospheric CO2concentrations were similar for the ETM2 and the better-described Palaeocene–Eocene Thermal Maximum,, 55.5 Myr ago.