Global wood anatomical perspective on the onset of the Late Antique Little Ice Age (LALIA) in the mid-6th century CE
Global wood anatomical perspective on the onset of the Late Antique Little Ice Age (LALIA) in the mid-6th century CE
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DOI：
10.1016/j.scib.2022.10.019
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发表时间：
2022-11-30
期刊：
影响因子：
18.9
通讯作者：
Piermattei, Alma
中科院分区：
文献类型：
--
作者：
Buntgen, Ulf;Crivellaro, Alan;Piermattei, Alma
与公元 536 年和 540 年左右的大型火山喷发有关，古代小冰河时代晚期的开始被描述为过去两千年来最冷的时期。然而，由于可用代理档案的分辨率和地理分布有限，这一异常寒冷阶段的确切时间和空间范围仍在争论中。在这里，我们使用来自两个半球 23 个森林地点和 20 个树种的 106 个木材解剖薄片来寻找公元 530 年至 550 年短暂夏季降温的细胞水平指纹。经过交叉年代测定和双重染色后，我们在北半球鉴定出了 89 个蓝环（缺乏细胞壁木质化）、9 个霜环（细胞变形和塌陷）和 93 个浅环（细胞壁增厚减少）。我们的网络揭示了公元 536 年 7 月中旬至 8 月初之间北美和欧亚大陆最强烈的气温下降的证据，而更局部的寒流发生在公元 532 年、540-43 年和 548 年的夏季。南方树木缺乏解剖学特征表明，平流层火山气溶胶对南半球温带地区的侵入有限，任何强迫都会因大气-海洋动力响应而减轻和/或集中在生长季节之外，或多种因素的组合。我们的研究结果证明了木材解剖学研究相对于传统树木年代学测量的优势，为地球系统模型提供了基准，支持对气候和历史纠葛的跨学科研究，并质疑全球气候平均值的相关性。 (c) 2022 年科学中国出版社。由 Elsevier B.V. 和中国科学出版社出版。
Linked to major volcanic eruptions around 536 and 540 CE, the onset of the Late Antique Little Ice Age has been described as the coldest period of the past two millennia. The exact timing and spatial extent of this exceptional cold phase are, however, still under debate because of the limited resolution and geographical distribution of the available proxy archives. Here, we use 106 wood anatomical thin sections from 23 forest sites and 20 tree species in both hemispheres to search for cell-level fingerprints of ephemeral summer cooling between 530 and 550 CE. After cross-dating and double-staining, we identified 89 Blue Rings (lack of cell wall lignification), nine Frost Rings (cell deformation and collapse), and 93 Light Rings (reduced cell wall thickening) in the Northern Hemisphere. Our network reveals evidence for the strongest temperature depression between mid-July and early-August 536 CE across North America and Eurasia, whereas more localised cold spells occurred in the summers of 532, 540-43, and 548 CE. The lack of anatomical signatures in the austral trees suggests limited incursion of stratospheric volcanic aerosol into the Southern Hemisphere extra-tropics, that any forcing was mitigated by atmosphere-ocean dynamical responses and/or concentrated outside the growing season, or a combination of factors. Our findings demonstrate the advantage of wood anatomical investigations over traditional dendrochronological measurements, provide a benchmark for Earth system models, support cross-disciplinary studies into the entanglements of climate and history, and question the relevance of global climate averages. (c) 2022 Science China Press. Published by Elsevier B.V. and Science China Press.