Analysing the timing of peak warming and minimum winter sea-ice extent in the Southern Ocean during MIS 5e
Analysing the timing of peak warming and minimum winter sea-ice extent in the Southern Ocean during MIS 5e
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DOI：
10.1016/j.quascirev.2019.106134
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发表时间：
2020-02-01
影响因子：
4
通讯作者：
Hillenbrand, C. -D.
中科院分区：
文献类型：
--
作者：
Chadwick, M.;Allen, C. S.;Hillenbrand, C. -D.
末次间冰期的高峰，海洋同位素阶段（MIS） 5e (130-116 ka)，为验证在未来人为变暖下可能活跃的气候反馈和强迫提供了有价值的“过程模拟”。重建整个南大洋（SO）的MIS 5e峰值增温和冬季最小海冰范围（WSIE）的精确时间将有助于识别冰-海系统内部的相互作用和反馈。在这里，我们提出了来自西南大西洋部门的新的MIS 5e海洋沉积物记录以及28个已发表的核心记录（年表标准化到LRO4 5180底栖生物堆；Lisiecki和Raymo， 2005），以研究整个SO的最小WSIE和峰值变暖的时间和顺序。海表温度（SSTs）在印度（20 E -150 E）和大西洋（70 W-20 E）扇区达到峰值最早，分别为128.7 0.8 ka和127.4 1.1 ka，其次是太平洋扇区（150 E-70 W），为124.9 3.6 ka。3个扇区的WSIE最小值出现在129 ~ 125 ka，与南极冰芯的-128 ka海盐通量最小值一致。最低WSIE似乎与7月55 S的日照高峰同时发生，这表明它可能与最温和的冬季有关。MIS 5e期间减少的WSIE可能会减少深层和底部水团的产生，抑制深海中CO2的储存，降低SO表层水的营养物质有效性。研究MIS 5e的广泛空间范围的代理记录是理解气候相互作用和在全球温度升高下活跃的过程的关键一步。(C) 2019 Elsevier Ltd.版权所有。
The peak of the Last Interglacial, Marine Isotope Stage (MIS) 5e (130-116 ka), provides a valuable 'process analogue' for validating the climatic feedbacks and forcings likely active under future anthropogenic warming. Reconstructing exact timings of MIS 5e peak warming and minimum winter sea-ice extent (WSIE) throughout the Southern Ocean (SO) will help to identify the interactions and feedbacks within the ice-ocean system. Here we present a new MIS 5e marine sediment record from the SW Atlantic sector together with 28 published core records (chronologies standardised to the LRO4 5180 benthic stack; Lisiecki and Raymo, 2005) to investigate the timing and sequence of minimum WSIE and peak warming across the SO. Sea-surface temperatures (SSTs) peaked earliest in the Indian (20 E -150 E) and Atlantic (70 W-20 E) sectors, at 128.7 0.8 ka and 127.4 1.1 ka respectively, followed by the Pacific sector (150 E-70 W) at 124.9 3.6 ka. The interval of minimum WSIE for all three sectors occurred within the period from 129-125 ka, consistent with the -128 ka sea salt flux minimum in Antarctic ice cores. Minimum WSIE appears to have coincided with peak July insolation at 55 S, suggesting it could be linked with the mildest winters. The reduced WSIE during MIS 5e would have likely reduced the production of deep- and bottom water masses, inhibiting storage of CO2 in the abyssal ocean and lowering nutrient availability in SO surface waters. Examining a wide spatial range of proxy records for MIS 5e is a critical step forward in understanding climatic interactions and processes that will be active under warmer global temperatures. (C) 2019 Elsevier Ltd. All rights reserved.