A synthesis of stalagmite δ18O records from the Asian summer monsoon domain over the last millennium (670-2000 CE)

Dataset for “The spatiotemporal variability of Asian summer monsoon over the last millennium governed by the Intertropical Convergence Zone”. This dataset includes: a new YX δ18O record covering the entire LM from Yongxing Cave (31°35'N, 111°14'E, 800 m) in the east slope of Mt. Shennongjia, central China, and a synthesis of stalagmite δ18O records from the Asian summer monsoon domain over the last millennium (670-2000 CE).
The dynamic linkage between climatic warming and the Asian summer monsoon (ASM) remains unclear, largely due to the limited understanding of the spatiotemporal variability of the ASM rainfall. Here, we present a new high-resolution stalagmite δ18O record from Yongxing Cave, central China and determine the leading mode and spatial pattern of 13 well-dated Chinese stalagmite δ18O records over the last millennium. The leading mode, representative of the change in ASM intensity, is closely related to the Northern Hemisphere temperature and negatively related to the South American summer monsoon (SASM) change, supporting that the Intertropical Convergence Zone (ITCZ) shifts modulate the interhemispheric monsoon changes. Our reconstruction and simulation further indicate a significant spatial heterogeneity in ASM rainfall during the Medieval Warm Period, related to the migration of the ITCZ, likely driven by greenhouse gas forcing. The synchronous weakening in ASM and SASM intensity during the Current Warming Period is likely attributed to anthropogenic warming-induced contraction of the ITCZ. Our findings highlight the key role of ITCZ changes in regulating the spatiotemporal variability of the ASM and associated rainfall in either natural or anthropogenic warming eras.

《近千年亚洲夏季风受热带辐合带（Intertropical Convergence Zone, ITCZ）调控的时空变异性》相关数据集。本数据集包含两类核心资料：一是采自中国中部神农架东坡永兴洞（北纬31°35′、东经111°14′，海拔800米）的永兴洞石笋氧同位素（δ¹⁸O）记录，该记录覆盖近千年完整时段；二是整合了公元670年—2000年近千年亚洲夏季风（Asian Summer Monsoon, ASM）影响区域内的石笋氧同位素记录合成数据集。当前气候增暖与亚洲夏季风（ASM）之间的动力关联仍不明确，这在很大程度上源于学界对亚洲夏季风降水时空变异性的认知局限。为此，本研究报道了采自中国中部永兴洞的全新高分辨率石笋氧同位素记录，并辨识了过去千年间13条定年可靠的中国石笋氧同位素记录的主导模态与空间分布格局。该主导模态表征亚洲夏季风强度变化，与北半球温度呈显著正相关，与南美夏季风（South American Summer Monsoon, SASM）变化呈负相关，这一结果支持热带辐合带（ITCZ）的位移调控跨半球季风变化的结论。本研究的重建结果与模拟试验进一步表明，中世纪暖期（Medieval Warm Period）期间亚洲夏季风降水存在显著空间异质性，该异质性与热带辐合带的迁移相关，其驱动机制大概率为温室气体强迫（greenhouse gas forcing）。现代暖期（Current Warming Period）期间，亚洲夏季风与南美夏季风强度同步减弱，这一现象可归因于人为增暖引发的热带辐合带收缩。本研究结果凸显了热带辐合带变化在调控自然或人为增暖时期亚洲夏季风及其关联降水的时空变异性中所发挥的关键作用。