High-Resolution Reconstruction of the South Asian Monsoon from the Puruogangri Ice Cores (Tibet)

这项研究将通过分析2000年9月10日至11月10日由国家科学基金资助的美国和中国联合考察期间从普罗岗里冰帽中发现的两个118.6米和214米的冰芯，产生有史以来第一个在青藏高原中部发现的气候和环境记录。这些独特的冰芯加入了青藏高原气候变化的其他档案，记录了20世纪前所未有的大气变暖。初步分析表明，这两个核心都含有可见的旱季尘埃层，可以追溯到公元前80年左右，并可以重建降水波动的历史，这可能反映受厄尔尼诺-南方涛动(ENSO)事件影响的季风系统强度的变化。这些岩心将被分析氧和氚的稳定同位素以及气溶胶化学，以帮助重建亚洲干旱的历史，并提供该区域过去的温度和大气环流模式的记录。普罗冈里冰层包含的信息是将长时间、高分辨率的记录从一极连接到另一极的基本组成部分，从而能够评估气候突变的全球性质。这一点很重要，因为青藏高原及其周围的山脉包含了极地地区以外最大的冰量。对气候敏感的冰川融化的水构成了印度河、长江、黄河和恒河等重要河流的源头。

This research will yield the first climatic and environmental records ever recovered from the center of the Tibetan Plateau by analyzing two ice cores measuring 118.6 and 214 meters that were recovered from the Puruogangri ice cap during a joint United States-China expedition between September 10 and November 10, 2000 funded by the National Science Foundation. These unique ice cores join other archives of changes in climate on the Tibetan Plateau that document an unprecedented warming of the atmosphere in the 20th century. Preliminary analyses indicate that both cores contain visible dry-season dust layers and may allow annual dating back to ~80 BC and the reconstruction of a history of precipitation fluctuations that are likely to reflect variations in the intensity of the monsoon system that is affected by El Nino-Southern Oscillation (ENSO) events. These cores will be analyzed for stable isotopes of oxygen and deuterium and aerosol chemistry to aid in the reconstruction of the history of Asian aridity and provide a record of the past temperatures and atmospheric circulation patterns for the region.The ice of the Puruogangri contains information that is an essential component in linking long, high-resolution records from pole to pole to allow an assessment of the global nature of abrupt climate variations. This is important because the Tibetan Plateau and surrounding mountain ranges contain the largest volume of ice outside the Polar Regions. The meltwater from the climatically sensitive glaciers form the headwaters of such important rivers as the Indus, Yangtze, Huang (Yellow) and the Ganges.