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利用长江三峡地区丰都水鸣洞石笋(NSM03)230 Th测年数据和碳同位素数据建立了AD1250～1750时段平均分辨率约为1a的石笋碳同位素时间序列.水鸣洞石笋碳同位素记录显示小冰期开始时间大约为AD1300,与已发表的树轮、孢粉等气候记录指示的小冰期开始时间在定年误差范围内一致;该记录同时显示在小冰期内部存在次一级气候波动,最明显的两次气候波动时间分别在15世纪中期和16世纪末,后者对应过去500年间亚洲季风活动最弱时期.对石笋碳同位素序列进行功率谱分析发现,小冰期气候存在98a和3～6a波动周期,分别与太阳活动世纪周期和ENSO周期相吻合,表明太阳活动是小冰期的主要形成机制,而海气耦合作用则直接影响小冰期气候.
The time series of carbon isotopes of stalagmites with an average resolution of about 1a in AD1250 ~ 1750 period were established by using the dating data of 230 Th and the carbon isotope of NSM03 in the Three Gorges area of the Yangtze River. The onset time of the glacial period is about AD1300, which is in agreement with published beginnings of the small-ice age indicated by climatic records such as tree-ring and sporopollen, within the range of annual errors. The record also shows that there are sub-primary climate fluctuations within the Little Ice Age, most notably The time of the two climatic fluctuations is respectively in the mid-15th century and the end of the 16th century, which corresponds to the weakest Asian monsoon over the past 500 years. The power spectrum analysis of stalagmite carbon isotopes shows that the paleoclimate has 98a and 3-6a cycles, Respectively, coincide with the solar cycles and ENSO cycles, indicating that solar activity is the main formation mechanism during the Little Ice Age, while the sea-air coupling directly affects the Little Ice Age climate.