High-Resolution Climatic Variability in Eastern China During the Last Millenia

研究大陆地区的古气候历史对于我们理解陆地生态系统和水文系统如何应对地球辐射收支的变化很重要。然而，由于大陆过程的多变性质，很少有这些过程的档案，特别是在这些过程的性质可以在非常高分辨率的时间尺度上追溯的地方，这些时间尺度也可以精确地确定日期。石灰岩洞穴的洞穴沉积就是这样一个潜在的储藏库。本研究的目的是研究石笋记录的年际到亚年代际古气候信号的时空变异性。此次考察覆盖了中国2000年来的东半部。最近的探索性研究鼓励人们能够有效地读取这种高分辨率的时间序列古气候变异性，这些研究表明，同位素(18O和13C)和化学(镁/锶/钙)分析相结合可以帮助破译过去温度、降水和植被的变化。此外，这些研究揭示了气候周期性，这可能与过去夏季风强度的变化有关。这一研究不仅有助于我们了解东亚地区的气候历史，而且有助于我们了解根源于全球气候变化的季风波动的影响因素。

Studies of the paleoclimatic history of continental areas are important to our understanding of how terrestrial ecosystems and hydrologic systems respond to changes in the earth's radiation budget. However, owing to the variable nature of continental processes, few archives of these processes are available, especially where the nature of these processes can be retraced at very high-resolution time scales which can also be precisely dated. The speleothem deposits of limestone caves represent one such potential repository. The purpose of this research is to investigate the interannual to sub-decadal paleoclimatic signals recorded by stalagmites in terms of both spatial and temporal variability. The investigation covers the eastern half of China over the past 2000 years. That such highly resolved time-series paleoclimate variability can be effectively read has been encouraged by recent exploratory studies which show that a combination of isotopic (18O and 13C) and chemical (Mg/Sr/Ca) analyses can help decipher changes in temperature, precipitation and vegetation in the past. Furthermore, these studies reveal a climatic cyclicity that may tie to past variations of the summer monsoon strength. This research will contribute to our understanding of not only the climate history of eastern Asia, but also the factors influencing the monsoon fluctuations that are rooted in the global climate variability.