High Resolution Reconstruction of Climate in the West Tropical Pacific Warm Pool from 26,000 Years Ago to Present: Stalagmites from Northern Borneo

该奖项将利用婆罗洲岛的洞穴数据，开发2.6万年前西太平洋暖池降水变化的高分辨率记录。该研究计划旨在调查过去26000年的十年到百年的变化，并确定在最后一次冰川消融期间发生的快速气候变化的结构和时间。这些洞穴记录可以回答热带太平洋是驱动还是被动响应热带气候变化的问题。从婆罗洲收集的洞穴主题为重建西太平洋暖池的次年代际水文变化提供了机会，该地区的降水受到厄尔尼诺-南方涛动（ENSO）变率的严重影响。对现有洞穴的地球化学和光学分析将在收集和分析新洞穴的同时进行。高精度U/Th日期将为地球化学气候代理记录（包括氧同位素、碳同位素和Mg/Ca比值）提供年龄控制。微米尺度成像技术将应用于洞穴，希望解决洞穴增长率的年度变化，这是另一个潜在的降水代理。一个实地项目将提供样本，用于校准和测试基于洞穴的气候代理记录的可重复性。校准工作将包括将活跃生长的洞穴顶部的超高分辨率代理重建与上一千年的仪器和代理气候数据进行比较。赤道太平洋地区从全新世到更新世的高分辨率气候记录将成为古气候数据档案的重要补充，在气候变率和影响研究中具有多种应用。

This award will develop high-resolution records of precipitation variability in the West Pacific Warm Pool from 26,000 years ago to present using speleothem data from the island of Borneo. The research plan is designed to investigate decadal to centennial variability across select windows of the last 26,000 years ago, and to determine the structure and timing of rapid climate changes that occurred during the last deglaciation. The question of whether the tropical Pacific drives, or passively responds to, extra tropical climate change can be answered with these speleothem records. Speleothems collected from Borneo provide an opportunity to reconstruct sub-decadal hydrological variability in the West Pacific Warm Pool, an area where precipitation is heavily influenced by El Nino Southern Oscillation (ENSO) variability. Geochemical and optical analysis of a speleothem already in hand will be carried out in parallel with the collection and analysis of new speleothems. High-precision U/Th dates will provide age control for the geochemical climate proxy records, which will include oxygen isotopes, carbon isotopes, and Mg/Ca ratios. Micron-scale imaging techniques will be applied to the speleothem in the hopes of resolving annual variations in speleothem growth rate, which represents another potential precipitation proxy. A field program will provide samples that will be used to calibrate and test the reproducibility of the speloethem-based climate proxy records. Calibration efforts will include comparing ultra-high-resolution proxy reconstructions from the tops of actively growing speleothems to both instrumental and proxy climate data for the last millennium. A high-resolution record of climate through the Holocene back into the Pleistocene from the equatorial Pacific region will be an important addition to the paleoclimate data archive with multiple applications in the study of climate variability and impact.