P2C2: Evaluating North Pacific Hydroclimate during the Holocene Using the Denali Ice Core Archive

该项目广泛寻求开发一个全新世长度水文气候记录从山。亨特（阿拉斯加）冰芯档案和评估北太平洋水文气候变化的背景下，现有的古气候数据和模型。该项目的部分动机是最近的观测和模拟研究，证明了太平洋的几十年变化和北极变暖之间的联系，在世纪初和自20世纪70年代以来。太平洋多年变率对北极气候的影响对海冰范围以及北极放大、海冰损失和中纬度冬季变率增强之间的可能联系有相当大的影响。以前的工作在山。亨特冰芯记录表明，在工业时代（自1850年以来），观测到的积雪增加一倍，夏季融化增加60倍，这与太平洋的多年变化有关，在上个千年是独一无二的。 这项研究旨在确认相同的驱动因素是否与整个全新世有关。确定太平洋-北极遥相关如何在温暖的间隔和仪器周期和上个千年之外的突发事件中做出反应，将为地球系统的敏感性提供有价值的见解。猎人冰芯档案，特别关注底部20米的双208米的表面到基岩的核心。初步的放射性同位素（14碳）分析表明，基冰的年龄超过10，000年。 具体的项目目标包括：1）使用额外的14-碳测量、火山灰年代学、激光消融ICPMS测量来扩展年度层计数和一套冰川学模型的时间尺度开发; 2）水文气候代用指标的开发，包括用于区域湿度估计的积雪（根据年代学和冰流模型）、综合水循环的稳定水同位素和大气动力学的微量元素化学; 3）与新的全新世长度的Mt.亨特记录与现有的北太平洋冰芯阵列和其他区域古气候资料的比较;和4）新的全新世长度的山。“潜在的更广泛影响”包括一个多方面的办法，其中包括在国际研究合作的背景下支持和指导一名早期职业科学家和一名博士生。 研究人员将与科罗拉多州立大学的教师和美国国家公园服务处的教师合作，根据山制作教育工具包。猎人冰芯记录，目标4-12年级的教育在阿拉斯加和缅因州学校。这个奖项反映了NSF的法定使命，并已被认为是值得通过评估使用基金会的智力价值和更广泛的影响审查标准的支持。

This project broadly seeks to develop a Holocene-length hydroclimate record from the Mt. Hunter (Alaska) ice core archive and evaluate North Pacific hydroclimate variability in context with existing paleoclimate data and models. This project is motivated in part by recent observational and modeling studies that demonstrate a connection between Pacific multidecadal variability and Arctic warming during the early 20th century and since the 1970s. The impact of Pacific multidecadal variability on Arctic climate has considerable implications for sea ice extent and possible linkages between Arctic amplification, sea ice loss, and enhanced mid-latitude winter variability. Previous work on the Mt. Hunter ice core record demonstrates that the observed doubling of snow accumulation and 60-fold increase in summer melt during the industrial era (since the year 1850) is linked to Pacific multidecadal variability and is unique in the last millennium. The research seeks to confirm if the same drivers are relevant for the entire Holocene. Establishing how the Pacific-Arctic teleconnection responded during warm intervals and abrupt events outside of the instrumental period and last millennium would provide valuable insight into Earth system sensitivity.The researchers will combine several complementary techniques in different sections of the Mt. Hunter ice core archive, with specific focus on the bottom 20 meters of the twin 208-meter surface-to-bedrock cores. Preliminary radiogenic isotope (14-Carbon) analyses demonstrate that the basal ice is more than 10,000 years old. Specific project objectives include: 1) time scale development using additional 14-Carbon measurements, tephrochronology, laser ablation ICPMS measurements to extend annual layer counting, and a suite of glaciological models; 2) hydroclimate proxy development, including snow accumulation for regional moisture estimates (based on chronology and ice flow models), stable water isotopes for the integrated water cycle, and trace element chemistry for atmospheric dynamics; 3) integration with the new Holocene-length Mt. Hunter record with the existing North Pacific ice core array and other regional paleoclimate data; and 4) comparison of the new Holocene-length Mt. Hunter record with Earth system models.The potential Broader Impacts include a multi-faceted approach that includes support and mentoring of an early career scientist and a doctoral student in the context of international research cooperation. The researchers will collaborate with Colorado State University faculty and U.S. National Park Service faculty personnel to fabricate educational kits based on the Mt. Hunter ice core record that target grades 4-12 education in Alaska and Maine schools.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.