Establishing more accurate chronologies for marine climate records using data from deep-sea cores from northern East China Sea

准确量化地球系统不同方面（深海、表层海洋和大气）变化时间差异的能力，是科学家能够解读气候变化背后的物理学的关键手段之一，以响应全球冰量、温室气体和太阳日射的变化。为了准确地量化这种变化时间的差异，需要从深海岩心中获得准确的气候数据。该项目旨在通过将深海岩心的海洋气候记录与中国葫芦-三宝洞穴中已确立的、高度准确的陆地矿床（洞穴沉积物）记录进行比较，提高海洋气候记录年龄的准确性。这项研究的结果将使海洋气候记录的年龄更加准确，从而为气候模型提供更好的数据，提高我们理解过去和未来气候变化的能力。这项工作有两个主要目标：1）了解东亚对季风气候变化强烈敏感性的机制2）显著提高过去35万年全球底栖三角洲18-O年代学的准确性。第一个目标是与位于日本和韩国之间的区域的综合大洋钻探计划（IODP）346考察队有关的长期国际合作努力的一部分。合作研究将持续超过本赠款提案的两年期限，而第二个目标是本提案的主要重点，并将在拟议的项目期限内完成。在中国东海北方IODP U1429站180 m长的3800个样品上测量浮游有孔虫（Globigerinoides ruber）δ 18-O和δ 13-C。这些数据将产生一个约425，000年的时间序列，时间分辨率约为100年，能够通过东亚季风系统的轨道尺度变化来分辨百年。来自德国基尔大学的合作者将分析同样的3800个底栖有孔虫（Cibicidoides wuellerstorfi）δ 18-O和δ 13-C样本。利用动态规划方法将植物三角洲18-O映射到放射性测年的葫芦-三宝洞穴沉积物三角洲18-O记录上，从而将这种高度精确的年龄尺度转换为成对的底栖海洋记录。这是可能的，因为洞穴和南极洲的18-O记录都是由相同的大尺度季风强迫（温度和降水）驱动的;地点U1428的位置、长度和沉积速率非常适合这项工作

The ability to accurately quantify differences in the timing of change in different aspects of the earth system (deep ocean, surface ocean, and atmosphere) is one of the key means by which scientists are able to decipher the physics underlying climate change in response to variability in global ice volume, greenhouse gasses, and solar insolation. To accurately quantify the differences in this timing of change requires accurate ages for climate data developed from deep-sea cores. This project seeks to improve the accuracy of ages for marine climate records developed from deep-sea cores by comparing these records to well-established, highly-accurate land-based records of mineral deposits (speloethems) in the Hulu-Sanbao cave in China. The results of this research will make ages for marine climate records more accurate, thus providing better data for climate models that enhance our ability to understand climate change, past and future. This proposed work has two main objectives:1) Understanding the mechanisms underlying the strong sensitivity of East Asia to monsoonal climate change2) Significantly increasing the accuracy of the global benthic delta 18-O chronology over the past 350,000 years. The first objective is part of a longer-term international collaborative effort associated with Integrated Ocean Drilling Program (IODP) Expedition 346, located in the region between Japan and Korea. The collaborative research will last beyond the two-year term of this grant proposal, whereas the second objective is the primary focus of this proposal and will be completed in the proposed project duration. Planktonic foraminifer (Globigerinoides ruber) delta 18-O and delta 13-C will be measured on 3800 samples spanning the 180 m length of the IODP Site U1429 in the northern East China Sea. This data will result in a ~425,000 year long time series with ~100 year temporal resolution, capable of resolving centennial through orbital-scale variability in the East Asian monsoon system. Collaborators from the University of Kiel, Germany, will analyze the same 3800 samples for benthic foraminifer (Cibicidoides wuellerstorfi) delta 18-O and delta 13-C. The plantonic delta 18-O will be mapped onto the radiometrically dated Hulu-Sanbao speleothem delta 18-O record using dynamic programming methods, thus transferring this highly accurate age scale into the paired benthic marine record. This is possible because both the cave and planktonic delta 18-O records are driven by the same large-scale monsoonal forcings (temperature and precipitation); the location, length, and sedimentation rates at Site U1428 are uniquely suited to this effort