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

本项目探索利用降水的氢、氧同位素组成作为中国洞穴沉积物气候重建的代表。该研究的主要目标是开发监测水文循环季节性的代用物。研究的指导原则是，洞穴洞穴三角洲氧-18记录了进入洞穴的降水的加权年平均同位素组成，而叶蜡三角洲氘监测降水的生长季节（通常为夏季）同位素组成。研究计划的指导假设是，叶蜡δ氘将具有与来自印度和东亚的夏季季风记录一致的相位响应，冬季信号将具有与北半球冬季太阳日照最小值和冰量最大值的综合效应一致的相位。主要的更广泛的影响包括支持代表性不足的少数民族学生，美中科学家之间的合作，以及在水资源紧张地区对水资源问题的科学关注，这将带来重要的社会效益。

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.