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

近千年来中国东部的高分辨率气候变化

• 批准号: 9818407
• 负责人: Teh-Lung Ku
• 金额: $ 31.5万
• 依托单位: University of Southern California
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1999
• 资助国家: 美国
• 起止时间: 1999-04-01 至 2002-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9818407&HistoricalAwards=false
• 关键词: Resolution; Climatic; Variability; Eastern; China

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.

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响应地球辐射收支的变化是非常重要的。然而，由于大陆过程的变化性质，这些过程的档案很少，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回溯的地方，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物就是这样一个潜在的储存库。本研究旨在探讨石笋记录的年际至次年代际古气候信号的时空变异性。调查覆盖了过去2000年的中国东半部。最近的探索性研究表明，同位素（18O和13C）和化学（Mg/Sr/Ca）分析的结合可以帮助破译过去温度、降水和植被的变化，这一发现鼓励了人们能够有效地解读这种高分辨率的时间序列古气候变率。此外，这些研究揭示了可能与过去夏季风强度变化有关的气候周期性。这项研究不仅有助于我们了解东亚的气候历史，而且有助于我们了解植根于全球气候变率的影响季风波动的因素。