近日，中国科学院地质与地球物理研究所谭宁团队研究了上新世-更新世过渡时期格陵兰冰盖演变的旋回性。相关论文于2026年1月22日发表在《中国科学：地球科学》杂志上。

上新世-更新世过渡期（300万至250万年前）是北极冰盖大规模扩张与增强的关键时期，格陵兰永久性冰盖的建立标志着地球进入南北两极的"冰室"气候状态。该时期大气CO₂浓度处于工业革命前与现代水平之间（约280-400 ppmv），为理解冰盖对外部强迫的响应提供了关键时间窗口。

研究组通过高分辨率气候模型与三维热力学冰盖模型，模拟不同CO₂情景下格陵兰冰盖的体积演变，并分析其在该时期的周期性行为。结果表明：当冰盖规模较小时，其变化受北纬65°夏季太阳辐射强烈驱动；随着冰盖扩张，其响应模式发生转变，逐渐转为以斜率周期为主导。与冰筏碎屑记录相符的格陵兰冰盖重建显示，约270万年后，扩张的冰盖表现出增强的亚轨道至千年尺度信号及更大的冰动力变率——这一模式与晚第四纪格陵兰冰芯中观测到的放大千年尺度气候事件相呼应。

此外，与深海氧同位素记录对比表明，270万年后格陵兰冰盖开始对4万年周期产生显著贡献，其变化略微领先于底栖有孔虫δ¹⁸O信号。该研究阐明了格陵兰冰盖的周期性演化规律，明确了其在上新世-更新世过渡期气候系统演化中的作用。

附：英文原文

Title: The cyclicity of Greenland ice sheet evolution during the Pliocene-Pleistocene transition

Author: Ning TAN, Zhengtang GUO, Chenxi XU, Bin HU, Zhongshi ZHANG

Issue&Volume: 2026/01/22

Abstract: The Pliocene-Pleistocene transition (3.0–2.5million years ago, Ma) was a critical period during which the Arctic ice sheets expanded extensively and intensified, with the establishment of a permanent ice sheet on Greenland marking the onset of a bipolar “icehouse” climate state. This interval, characterized by atmospheric CO2 concentrations between pre-industrial and modern levels (～280–400 ppmv), provides a critical time window for understanding ice-sheet response to external forcing. Using a high-resolution climate model and a 3D thermomechanical ice sheet model, we simulate the Greenland Ice Sheet (GrIS) volume evolution under different CO2 scenarios and analyze its periodic behavior during this period. Our results show that when the GrIS volume was small, its variability was strongly paced by 65°N summer insolation. As the ice sheet grew, its response shifted, becoming increasingly dominated by the obliquity cycle. The GrIS volume reconstruction, consistent with ice-rafted debris records, indicates that after approximately 2.7Ma, the expanded GrIS exhibited enhanced suborbital to millennial-scale signals and greater ice dynamical variability—a pattern echoing the amplified millennial-scale climate events observed in late Quaternary Greenland ice cores. Furthermore, comparison with deep-sea oxygen isotope records shows that the GrIS began to significantly contribute to the 40,000-year cycle after 2.7Ma, with its changes slightly leading the signal of the benthic δ18O. This study clarifies the GrIS’s cyclic evolution and constrains its role in the climate system evolution during the Pliocene-Pleistocene transition.

DOI: 10.1007/s11430-025-1796-4

Source: https://www.sciengine.com/SCES/doi/10.1007/s11430-025-1796-4