Collaborative Research: Common Era Climate Variability from Marine Proxy Surrogate Reconstructions

合作研究：海洋代理替代重建的共同时代气候变化

• 批准号: 1536418
• 负责人: Casey Saenger
• 金额: $ 14.58万
• 依托单位: University of Washington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-08-15 至 2018-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1536418&HistoricalAwards=false
• 关键词: Collaborative; Research; Common; Era; Climate

The density-driven Atlantic meridional overturning circulation (AMOC), which can influence climate on regional and global scales, is poorly constrained by brief observational records. This adds considerable uncertainty to the interpretation of modern climate trends and to forecasts of future change. The proposed work will extend the instrumental record by generating quantitative reconstructions of AMOC variability over the past 2,000 years within the physically consistent framework of coupled ocean-atmosphere general circulation model (AOGCM) simulations. The project will identify the significant patterns of AMOC variability that emerge from proxy data and their most likely causes. Synthetic pseudoproxies will be used to evaluate the skill of these results and identify sites that might reduce uncertainty in the future. Results from this work will provide a valuable baseline for natural AMOC-climate relationships, giving context to recent trends that will inform future climate change forecasts. The research will combine a network of marine proxy records spanning the past two millennia, compiled during Phase 1 of the PAGES Ocean2K initiative, with Climate Model Intercomparison Project (CMIP) isotope enabled AOGCMs to estimate AMOC using proxy surrogate reconstructions (PSRs). The uncertainty in the PSR method arising from methodological choices, data type, proxy distribution and observational error will be evaluated based, in part, on pseudoproxy experiments (PPEs). PSRs represent completely consistent physical systems, allowing AMOC strength and pattern in skillful PSRs to be compared with atmospheric circulation, external radiative forcing and other variables to evaluate their dynamical links. Confidence in PSRs will likely increase as the proxy network expands in the future, and a PPE will be used to identify additional locations from which additional data might reduce the uncertainty in PSR-based estimates of AMOC (and other variables), providing a target for future work. In addition to the broader scientific relevance of advancing the international Oceans2K and model intercomparison project efforts, other notable impacts include support of an early career researcher with no prior NSF support, research opportunities for undergraduates, and involvement of both researchers in local education initiatives for minorities and high school students.

密度驱动的大西洋经向翻转环流（AMOC）可以在区域和全球范围内影响气候，但很少受到简短观测记录的限制。这给现代气候趋势的解释和未来变化的预测增加了相当大的不确定性。拟议的工作将通过在海洋-大气耦合大气环流模型 (AOGCM) 模拟的物理一致框架内生成过去 2000 年 AMOC 变化的定量重建来扩展仪器记录。该项目将确定代理数据中出现的 AMOC 变异的重要模式及其最可能的原因。合成伪代理将用于评估这些结果的技能，并识别可能减少未来不确定性的站点。这项工作的结果将为自然 AMOC 与气候关系提供有价值的基线，为近期趋势提供背景信息，为未来的气候变化预测提供信息。该研究将结合过去两千年的海洋代理记录网络（在 PAGES Ocean2K 计划第一阶段编制）和气候模型比对项目 (CMIP) 同位素，使 AOGCM 能够使用代理代理重建 (PSR) 来估计 AMOC。 PSR 方法中因方法选择、数据类型、代理分布和观测误差而产生的不确定性将部分基于伪代理实验 (PPE) 进行评估。 PSR 代表完全一致的物理系统，允许将熟练 PSR 中的 AMOC 强度和模式与大气环流、外部辐射强迫和其他变量进行比较，以评估其动态联系。随着未来代理网络的扩展，对 PSR 的信心可能会增加，并且 PPE 将用于识别其他位置，从这些位置获得的附加数据可能会减少基于 PSR 的 AMOC（和其他变量）估计的不确定性，从而为未来的工作。除了推进国际 Oceans2K 和模型比对项目工作的更广泛的科学相关性之外，其他显着影响还包括为早期没有 NSF 支持的早期职业研究人员提供支持、为本科生提供研究机会以及两名研究人员参与当地少数民族教育计划和高中生。