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沿着上升速度快于全球海平面，预计在世纪将急剧加速。这种加速的不确定性和社会影响突出表明，需要更好地了解区域海平面与气候之间的关系。跨越过去~2,000年（"共同时代"）的高分辨率海平面代用指标揭示了与动态海平面（DSL）变化相关的沿东海岸的世纪尺度分米振幅（高达~20厘米）变率沿着。这些变化为气候模型提供了一个独特的基准，也是21世纪气候驱动的海平面变化的最接近的观测模拟。该项目将采用统计和动力学模型，以提高对沿着东海岸共同时代海平面变化及其与气候关系的科学认识。该研究小组将利用这些知识为21世纪世纪DSL变化的预测以及当前一代气候模型捕捉这些变化的能力提供信息，从而为高风险的北美东部海岸沿着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，以培养古气候、气候建模、以及天气和气候风险评估。项目团队将面对代理记录的稀疏性和当代古气候模拟的局限性，通过使用广泛的统计数据来测试关于海平面变化驱动因素的假设，和基于动态的建模策略。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与其他气候指数之间的联系（例如，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）;以及（3）进行和分析耦合气候模式模拟。气候模式模拟将被迫代理派生的表面通量和验证的综合互补气候重建。模拟将揭示重建中发现的相关性背后的动力学机制，并展示仪器记录中观察到的关系是否在几十年到一百年的时间尺度上持续存在。该研究有望导致一个共同时代的海平面和气候变化的更完整的解释。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

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.