The spatio-temporal structure of the Lateglacial to early Holocene transition reconstructed from the pollen record of Lake Suigetsu and its precise correlation with other key global archives: Implications for palaeoclimatology and archaeology
The spatio-temporal structure of the Lateglacial to early Holocene transition reconstructed from the pollen record of Lake Suigetsu and its precise correlation with other key global archives: Implications for palaeoclimatology and archaeology
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DOI：
10.1016/j.gloplacha.2021.103493
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发表时间：
2021-06-03
影响因子：
3.9
通讯作者：
Yasuda, Yoshinori
中科院分区：
文献类型：
--
作者：
Nakagawa, Takeshi;Tarasov, Pavel;Yasuda, Yoshinori
不同地区气候事件的超前、滞后或同步是理解气候变化机制的关键，因为它们能为气候系统各组成部分之间的因果联系提供见解。经过充分研究的从晚冰期到全新世早期（约1.6 - 1万年）的过渡包含了几次气候突变，这使得这一时期非常适合评估气候变化的时空结构。然而，地区之间过去气候事件发生时间的比较往往只是假设性的，因为特定地点的年龄尺度不一定相互同步。在此，我们展示了来自日本水俣湖年纹层沉积物的新花粉数据（n = 510）以及年均温度重建结果。水俣湖的碳 - 14数据集是IntCal20放射性碳校准模型的一个组成部分，其中绝对年龄尺度是按照最高标准建立的。其超高精度的年代学，以及冰芯宇宙成因同位素研究的最新进展，使得能够在水俣湖、格陵兰以及其他跨地区的关键替代指标记录之间进行时间上连贯的比较。我们表明，晚冰期寒冷逆转（相当于GS - 1/新仙女木期）和全新世的起始在东亚和北大西洋是同步的，而晚冰期间冰阶（相当于GI - 1/博林 - 阿勒罗德期）在东亚比在北大西洋早约两个世纪开始。青藏高原和喜马拉雅山脉南北之间西风急流的双峰迁移（或“跳跃”）可能作为一个阈值系统运作，导致了东亚和南亚（可能还有西亚）变化的突然性。亚洲的这一阈值以及北大西洋的另一个主要阈值，与大西洋经向翻转环流（AMOC）的开启/关闭相关，在不同时间被跨越，导致了突变的数百年不同步，以及过渡阶段各地区气候模式的差异。这种差异可能扰乱了纬向环流，并在过渡期间产生了不稳定的气候。另一方面，气候稳定的间隔期与定居生活和农业的开始相吻合，这意味着除非气候稳定，并且在一定程度上可预测，否则这些新的生活方式和技术是不合理的。
Leads, lags, or synchronies in climatic events among different regions are key to understanding mechanisms of climate change, as they provide insights into the causal linkages among components of the climate system. The well-studied transition from the Lateglacial to early Holocene (ca. 16-10 ka) contains several abrupt climatic shifts, making this period ideal for assessing the spatio-temporal structure of climate change. However, comparisons of timings of past climatic events among regions often remain hypothetical because site-specific age scales are not necessarily synchronised to each other. Here we present new pollen data (n = 510) and mean annual temperature reconstruction from the annually laminated sediments of Lake Suigetsu, Japan. Suigetsu's C-14 dataset is an integral component of the IntCal20 radiocarbon calibration model, in which the absolute age scale is established to the highest standard. Its exceptionally high-precision chronology, along with recent advances in cosmogenic isotope studies of ice cores, enables temporally coherent comparisons among Suigetsu, Greenland, and other key proxy records across regions.We show that the onsets of the Lateglacial cold reversal (equivalent to GS-1/Younger Dryas) and the Holocene were synchronous between East Asia and the North Atlantic, whereas the Lateglacial interstadial (equivalent to GI-1/Bolling-Allerod) started ca. two centuries earlier in East Asia than in the North Atlantic. Bimodal migration (or 'jump') of the westerly jet between north and south of the Tibetan plateau and Himalayas may have operated as a threshold system responsible for the abruptness of the change in East and South (and possibly also West) Asia. That threshold in Asia and another major threshold in the North Atlantic, associated with switching on/off of the Atlantic meridional overturning circulation (AMOC), were crossed at different times, producing a multi-centennial asynchrony of abrupt changes, as well as a disparity of climatic modes among regions during the transitional phases. Such disparity may have disturbed zonal circulation and generated unstable climate during transitions. The intervening periods with stable climate, on the other hand, coincided with the beginnings of sedentary life and agriculture, implying that these new lifestyles and technologies were not rational unless climate was stable and thus, to a certain extent, predictable.