Wu Zhipeng, Yin Qiuzhen, Berger André, Guo Zhengtang
Earth and Climate Research Center, Earth and Life Institute, Université catholique de Louvain, Louvain-la-Neuve, Belgium.
State Key Laboratory of Lithospheric and Environmental Coevolution, Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing, China.
Nat Commun. 2025 Feb 21;16(1):1841. doi: 10.1038/s41467-025-57076-2.
The western equatorial Pacific (WEP) plays an important role on global climate. Many studies have reported the classical orbital cycles in the WEP temperature variations, but the half-precession (~10-kyr) cycle, despite its uniqueness in the equatorial insolation, is paid less attention. Here, a systematic study on the half-precession cycle in the WEP temperature is performed based on the analysis of transient climate simulations covering the past 800,000 years, combined with high-resolution temperature reconstructions. The results show that the half-precession cycle is a significant signal in the WEP temperature. The model simulations show that in response to astronomical forcing, the half-precession cycle in the WEP surface and upper subsurface temperatures is driven by maximum equatorial insolation, while it is driven by bi-hemisphere maximum insolation in the lower subsurface temperature. The different forcing mechanisms at different depths are related to distinct local ocean circulation patterns. The astronomically-induced half-precession cycles are modulated by eccentricity, CO and ice sheets. Given the importance of WEP on global climate, the half-precession cycle in the WEP temperature may contribute to the half-precession signal recorded in other regions.
赤道西太平洋（WEP）在全球气候中起着重要作用。许多研究报道了赤道西太平洋温度变化中的经典轨道周期，但半岁差（约10 kyr）周期，尽管其在赤道日照方面具有独特性，却较少受到关注。在此，基于对过去80万年的瞬态气候模拟分析，并结合高分辨率温度重建，对赤道西太平洋温度中的半岁差周期进行了系统研究。结果表明，半岁差周期是赤道西太平洋温度中的一个显著信号。模型模拟显示，响应天文强迫，赤道西太平洋表层和上层次表层温度中的半岁差周期由最大赤道日照驱动，而在次表层较低温度中则由双半球最大日照驱动。不同深度的不同强迫机制与不同的局部海洋环流模式有关。由天文因素引起的半岁差周期受到偏心率、二氧化碳和冰盖的调制。鉴于赤道西太平洋对全球气候的重要性，赤道西太平洋温度中的半岁差周期可能对其他地区记录的半岁差信号有贡献。
