Collaborative Research: P2C2--Multi-proxy Reconstructions of North Pacific Decadal Variability from Bivalve Mollusks and Trees

该项目有三个主要的科学目标：1）对北太平洋工业化前年代际变率范围进行基准测试，以便与观测到的20世纪模式以及模拟的古和未来半球气候数据集进行比较; 2）解决现有树木之间协议不佳的问题-北太平洋十年变化的环形重建以及海洋和陆地系统之间的联系在性质和强度上随时间变化的可能性;通过比较北太平洋年代际变率的重建和厄尔尼诺南方涛动的独立重建，研究北太平洋和热带太平洋之间的长期联系。北太平洋的年代际变率在北美西部的社会经济和环境动态中起着重要作用，对渔业生产、森林生长、野火、干旱、还有积雪这一地球气候系统的主要模式在历史上被称为太平洋十年涛动，其特征已在亚洲、澳大利亚和南美洲的生物和物理指标中得到确认，甚至在全球范围的海平面和表面温度趋势中也得到确认。 然而，在公元1900年之前，它的行为仍然存在相当大的和长期的不确定性，在多个世纪的背景下，20世纪世纪的动态在多大程度上是非典型的。在这项研究中，三个古气候代用数据源将被整合到重建北太平洋年代际变化。首先，一个网络的确切日期的年表将产生从长寿命的海洋双壳类太平洋象拔蚌（Panopea generosa），其增长被证明是高度敏感的海面温度的增长增量宽度。在象拔蚌的放射性碳（14 C）数据，一旦交叉日期，并放置在适当的日历年，将产生另一个角度对北太平洋十年变化的信息，长期变化的水团年龄和沿海海洋环流。最后，现有的树轮年表从北太平洋沿岸将与象拔蚌数据，以最大限度地提高重建能力和准确性的多代理propages.The更广泛的影响涉及支持早期职业科学家，格拉德生，博士后，并将涉及本科生的研究活动。该研究旨在提供有用的见解PDO的变化，区域树木年轮记录之间的分歧，在过去的土著文化和渔业的环境设置的原因，并深入了解海洋水库的影响。如果能够实现，这些将是重要的科学影响。这项提议有一定的风险，但新的科学认识可能带来的好处抵消了这种风险。

This project has three main scientific goals aimed at: 1) benchmarking pre-industrial ranges of North Pacific decadal variability for comparison to observed 20th century patterns as well as modeled paleo and future datasets of hemispheric climate; 2) addressing unresolved questions regarding poor agreement among existing tree-ring reconstructions of North Pacific decadal variability and the possibility that linkages across marine and terrestrial systems vary in character and strength over time; and 3) examining long-term linkages between the North Pacific and tropical Pacific by comparing reconstructions of North Pacific decadal variability to independent reconstructions of the El Nino Southern Oscillation.Decadal-scale variability in the North Pacific Ocean plays a fundamental role in the socioeconomic and environmental dynamics of western North America with clearly established implications for fisheries production, forest growth, wildfire, drought, and snowpack. This major mode of Earth's climate system has historically been characterized as the Pacific Decadal Oscillation for which signatures have been identified in biological and physical indicators across Asia, Australia, and South America and even in global-scale trends in sea level and surface temperature. However, there remains considerable and long-standing uncertainly in its behavior prior to AD 1900 and the extent to which 20th century dynamics are atypical in a multi-centennial context. In this study, three paleoclimate proxy data sources will be integrated to reconstruct North Pacific decadal variability. First, a network of exactly dated chronologies will be produced from growth-increment widths of long-lived marine bivalve Pacific geoduck (Panopea generosa), the growth of which is demonstrated to be highly sensitive to sea surface temperatures. Radiocarbon (14C) data in geoducks, once cross-dated and placed in the appropriate calendar years, will yield another perspective on North Pacific decadal variability with information regarding long-term changes in water mass age and coastal ocean circulation. Finally, existing tree-ring chronologies from the North Pacific rim will be integrated with the geoduck data to maximize reconstruction power and accuracy in a multi-proxy approach.The broader impacts involve support for an early career scientist, grad student, and post-doc, and will involve undergraduate students in the research activities. The research aims to provide useful insights into PDO variability, the reasons for divergence among regional tree ring records, the environmental settings of native cultures and fisheries in the past, and insights into marine reservoir effects. If achieved, these would be important scientific impacts. The proposal has an element of risk but that risk is offset by the potential benefit in new scientific understanding.