Summer Monsoon Rainfall Variability in Central China over the Past 4700 Years and Its Possible Link to Solar Activity
Summer Monsoon Rainfall Variability in Central China over the Past 4700 Years and Its Possible Link to Solar Activity
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DOI：
10.1007/s13351-021-0168-1
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发表时间：
2021-08
影响因子：
3.2
通讯作者：
Jingwei Zhang;Kan Zhao;X. Kong;Yongjin Wang;Xianfang Wang;Shushuang Liu;Zhenjun Wang;Hai Cheng-H
中科院分区：
文献类型：
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作者：
Jingwei Zhang;Kan Zhao;X. Kong;Yongjin Wang;Xianfang Wang;Shushuang Liu;Zhenjun Wang;Hai Cheng-H
基于467对δ~(18)O和δ~(13)C记录和来自中国中部西牛洞石笋(BF_4)的8230Th测年，我们重建了过去4700年来∼的9年分辨率季风降水记录。我们的δ18O记录与相邻地区的东亚夏季风降水信号在重叠时段内具有良好的一致性，这表明δ18O信号可以被解释为季风降水的代理信号。δ13C的变化与洞穴遗址局部过程的变化以及区域降水和温度的变化有关。根据δ18O记录，在4500-1200、3500-3200、2800-2500、1900-1600、1400-1200、700-500和400-200a BP可以识别出一系列的旱期，而在4200-3600、2400-2200、3200-2800、1100-900、600-400和200-100年BP可以识别出一系列的湿期。对我们的δ18O记录进行的功率谱分析显示，在∼470和∼80年有显著的周期，与典型的太阳周期变化相吻合。这一结果表明，太阳活动的变化对中国中部季风降水的百年-年代际变化起主导作用。由于过去4700年太阳辐照度的微小变化(小于1.5W m−2)，我们的记录进一步与厄尔尼诺-南方涛动和太平洋年代际涛动进行了比较，证实了太阳强迫季风降水变化可能被厄尔尼诺-南方涛动和太平洋年代际涛动的变化放大。从600年到150年(小冰期)，∼-2‰在δ-18O和δ-13C记录中都有正移，表明气候类型为冷/干。通过我们的δ18O和δ13C记录与历史文献的比较，我们认为公元前450年至250年的气候恶化可能在明末造成了严重的社会动荡。
Based on 467 pairs of δ18O and δ13C records and 8230Th dates from a stalagmite (BF4) from Xiniu Cave, central China, we present a reconstruction of ∼9-yr resolution monsoon rainfall record for the past 4700 years. Our δ18O record shows good coherence with East Asian summer monsoon (EASM) rainfall proxies from adjacent regions during the overlapping intervals, suggesting that δ18O signal in BF4 can be interpreted as a monsoon rainfall proxy. The δ13C variations are related to changes in local processes at the cave site, and regional rainfall and temperature changes. Based on the δ18O record, a series of dry periods can be identified at 4500–1200, 3500–3200, 2800–2500, 1900–1600, 1400–1200, 700–500, and 400–200 yr BP, while a series of wet periods can be identified at 4200–3600, 2400–2200, 3200–2800, 1100–900, 600–400, and 200–100 yr BP. Power spectrum analysis on our δ18O record reveals significant cycles at ∼470 and ∼80 yr, coinciding with the typical solar periodic variations. This result suggests that changes in solar activity play a dominant role in driving centennial-decadal monsoon rainfall variation in central China. Due to minor changes in solar irradiance (less than 1.5 W m−2) over the past 4700 years, our record was further compared to the El Niño-Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO) proxies, confirming that solar forcing on monsoon rainfall changes might be amplified by the ENSO and PDO variations. From 600 to 150 yr BP (the Little Ice Age, LIA), a positive shift of ∼2‰ can be revealed in both the δ18O and δ13C records, indicating a cold/dry climatic pattern. By comparing our δ18O and δ13C records with historical documents, we suggest that the climatic deteriorations between 450 and 250 yr BP may have caused serious social unrest at the end of the Ming Dynasty.