Late Holocene increase of winter precipitation in mid-continental North America from a seasonally resolved speleothem record
Late Holocene increase of winter precipitation in mid-continental North America from a seasonally resolved speleothem record
复制标题
根据季节性解析的洞穴记录，北美洲中部大陆冬季降水量增加
DOI：
10.1130/g50096.1
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发表时间：
2022
期刊：
影响因子：
5.8
通讯作者：
Kitajima, Kouki
中科院分区：
文献类型：
--
作者：
Batchelor, Cameron J.;Marcott, Shaun A.;Orland, Ian J.;Kitajima, Kouki
对全新世的次年度气候重建是罕见的，尽管这种记录能够更好地了解驱动次年气候变异性的根本因素。我们使用激光共聚焦荧光显微镜成像和自动二次离子质谱仪显微分析来解析北美大陆中部晚全新世(2.7ka-2.1ka)洞穴动物的季节性氧同位素(δ18O)记录。我们通过测量全新世晚期600年期间117个年度波段内的δ18O变异性(Δ18O)来做到这一点。Δ18O值在2.4±0.1ka以后的变化反映了冬季降水量的增加。我们的研究直接测量了过去的季节性，对北美中部全新世晚期发生的季节性降水模式的变化提供了新的见解，并为理解该地区复杂的降水和温度历史增加了新的工具。
Subannual climate reconstructions of the Holocene are rare despite the ability of such records to provide a better understanding of the underlying factors that drive subannual climate variability. We used specialized confocal laser fluorescent microscope imaging and automated secondary ion mass spectrometry microanalysis to resolve a seasonal oxygen isotope (δ18O) record of a late Holocene–aged (2.7–2.1 ka) speleothem from mid-continental North America. We did this by measuring intra-band δ18O variability (Δ18O) within 117 annual bands over a 600 yr span of the late Holocene. We interpret a change in Δ18O values after 2.4 ± 0.1 ka to reflect an increase in the amount of winter precipitation. Our study produced direct measurements of past seasonality, offers new insights into shifting seasonal precipitation patterns that occurred during the late Holocene in central North America, and adds a new tool for understanding the complex precipitation and temperature histories of this region.