Temperature and Summer Monsoon Variability During the Past 500 Ka in China

这个奖项是为了表彰对中国三个洞穴中生长了50万年的石笋标本的同位素组成的研究：西安南部的佛洞、湖南西北部的黄龙洞和桂林南部的凤玉洞。石笋的年代将由TIMS u系列方法确定，以建立精确的时间框架，在此框架上，d18O和d13C的变化将被检查。在这些石笋中，d18O的长期变化提供了温度变化的历史，较轻的d18O值反映了较冷的气候。d13C记录反映了植被的变化，如温暖和干燥的条件降低了C3 /C4植物的比例、植被密度和C3植物中羧基化的13C分馏分，从而导致d13C值升高。根据同位素测量，支持者将以102 -103年的分辨率重建过去500 ka的古温度和古季风变化记录。然后，支持者将它们与中国中部的黄土记录和海洋氧同位素记录进行比较，以研究冬季季风对全球冰量变化的响应。

This award is for a study of the isotopic composition of stalagmite specimens grown over the past 500,000 years in three caves in China: Buddha Cave south of Xian, Huanglong Cave in northwestern Hunan, and Fengyu Cave south of Guilin. The stalagmites will be dated by TIMS U-series methods to establish precise time frameworks upon which the variations of d18O and d13C are to be examined. In these stalagmites the long-term d18O variations provide the history of temperature changes, with lighter d18O values reflecting colder climate. The d13C record represents vegetation changes, such that warm and dry conditions reduce the C3 /C4 plant ratio, the density of vegetation, and the 13C fractionation for carboxylation in C3 plants, giving rise to heavier d13C values. From the isotopic measurements, the proponents will reconstruct records of the paleotemperature and paleomonsoon variability over the past 500 ka, at 102 -103 year resolutions. The proponents will then compare them with the loess records from Central China and the marine oxygen isotope records, to investigate the response of the winter monsoon to global ice volume change.