P2C2: A Hydrogen Isotopic Approach to Resolving Precipitation Seasonality: Application to East Asian Speleothem Oxygen Isotopes

该项目探索使用降水的氢和氧同位素组成作为中国洞穴沉积物气候重建的代理。 该研究的主要目标是开发监测水文循环季节性的代理。指导研究的原则是洞穴沉积物三角洲氧-18记录降水的加权年平均同位素组成，使其进入洞穴，而三角洲叶蜡氘监测生长季节（通常是夏季）降水的同位素组成。该研究计划的指导假设是，叶蜡的三角洲氘将有一个相位响应与印度和东亚的夏季季风记录一致，冬季信号将有一个相位与北方半球冬季太阳日射最小值和冰量最大值的综合影响一致。主要的更广泛的影响涉及支持一个代表性不足的少数民族学生，中美科学家之间的合作，以及对水资源问题的科学关注，在一个水资源紧张的地区，具有重要的社会效益。

This project explores using the hydrogen and oxygen isotopic composition of precipitation as a proxy for climate reconstructions from Chinese cave deposits. The primary goal of the research is to develop proxies for monitoring seasonality in hydrologic cycles.The guiding research principle is that cave speleothem delta Oxygen-18 records the weighted annual average isotopic composition of precipitation making it to the cave whereas the delta Deuterium of leaf wax monitors the growing season (typically summer) isotopic composition of precipitation. The research plan is guided by the hypothesis that the delta Deuterium of leaf wax will have a phase response consistent with summer-monsoon records from India and East Asia and that the winter signal will have a phase consistent with the combined effects of northern hemisphere winter solar insolation minima and ice volume maxima.The primary broader impacts involve support for an underrepresented minority student, collaboration among U.S. and Chinese scientists, and a scientific focus on water resource issues in a water-stressed region that carries important social benefits.