Collaborative Research: P2C2 -- Connecting Common Era climate and sea level variability along the Eastern North American coastline

北美东部海岸线的海平面上升速度快于全球海平面，预计在21世纪将急剧加速。这种加速的不确定性和社会影响强调了有必要更好地了解区域海平面和气候之间的关系。过去~ 2000年（“Common Era”）的高分辨率海平面代用物揭示了与动态海平面（DSL）变化相关的东海岸世纪尺度、分米幅度（高达~20厘米）的变化。这些变化为气候模式提供了独特的基准，并为21世纪气候驱动的海平面变化提供了最接近的观测模拟。该项目将采用统计和动力学模型来提高对东海岸Common Era海平面变化及其与气候关系的科学认识。研究小组将利用这些知识为21世纪DSL变化的预测提供信息，并利用当前一代气候模型捕捉这些变化的能力，从而为高风险的北美东部沿海地区的沿海恢复能力提供信息。该项目将为一名早期职业科学家和一名研究生提供资金和机会，以发展古气候、气候建模以及天气和气候风险评估方面的各种技能和合作伙伴。项目团队将通过使用广泛的基于统计和动态的建模策略测试关于海平面变化驱动因素的假设，来面对代理记录的稀疏性和当代古气候模拟的局限性。项目任务包括：(1)严格评估使用分层时空统计框架生成的区域DSL重建的鲁棒性；(2)利用统计框架评估DSL与其他气候指数（如北大西洋涛动、大西洋经向翻转环流、海面温度和盐度、热带辐合带位置）之间的联系；(3)进行和分析耦合气候模式的模拟。气候模式的模拟将受到代理导出的地表通量的影响，并通过综合互补的气候重建加以验证。模拟将揭示在重建中发现的相关性的动力机制，并证明在仪器记录中观察到的关系是否在几十年到百年的时间尺度上持续存在。这项研究预计将导致对普通时代海平面和气候变化的更完整的解释。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Sea level along the eastern North American coastline is rising faster than global sea level and is expected to accelerate dramatically over the 21st century. The uncertainty and societal impact of this acceleration underscores the need for an improved understanding of relationships between regional sea level and climate. High-resolution sea level proxies spanning the past ~2,000 years (the "Common Era") reveal century-scale, decimeter-amplitude (up to ~20-cm), variability along the east coast associated with changes in dynamic sea level (DSL). These changes offer a unique benchmark for climate models, and the closest observational analog for climate-driven sea level change expected in the 21st century. This project will employ statistical and dynamical models to improve the scientific understanding of Common Era sea level changes along the east coast and their relationship with climate. The research team will leverage this knowledge to inform projections of 21st century DSL change and the ability of current-generation climate models to capture those changes, in turn informing coastal resilience efforts along the high-risk eastern North American coast. The project will provide funding and opportunities for an early career scientist and a graduate student to develop a diverse set of skills and collaborators in paleoclimate, climate modeling, and weather and climate risk assessment.The project team will confront the sparsity of the proxy record and the limitations of current-generation paleoclimate simulations by testing hypotheses about the drivers of sea level variability using a broad statistically- and dynamically-based modeling strategy. Project tasks include: (1) a rigorous assessment of the robustness of regional DSL reconstructions generated with a hierarchical spatio-temporal statistical framework; (2) leveraging the statistical framework to assess linkages between DSL and other climate indices (e.g., North Atlantic Oscillation, Atlantic Meridional Overturning Circulation, sea surface temperature and salinity, Intertropical Convergence Zone position); and (3) conducting and analyzing coupled climate model simulations. Climate model simulations will be forced by proxy-derived surface fluxes and validated by a synthesis of complementary climate reconstructions. The simulations will reveal the dynamical mechanisms underlying correlations found in reconstructions and demonstrate whether relationships observed in the instrumental record persist over multidecadal-to-centennial timescales. The research is expected to lead to a more complete interpretation of Common Era sea level and climate variability.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.