ALPACA - Advancing the Long-range Prediction, Attribution, and forecast Calibration of AMOC and its climate impacts

这是一个由美国国家科学基金会地球科学理事会（NSF/GEO）和英国国家环境研究委员会（NERC）通过NSF/GEO-NERC牵头机构协议共同资助的项目。该协议允许美国/英国提交一份联合提案，并由其调查员拥有最大比例预算的机构进行同行评审。在成功地共同确定一个奖项推荐后，每个机构资助预算的比例，以支持各自国家机构的科学家。该项目旨在提高对大西洋经向翻转环流（AMOC）可预测性的认识。这项国际合作的总体目标是量化、理解和提高我们预测AMOC及其在季节-十年（S2D）时间尺度上的气候影响的能力。它将利用AMOC观测（RAPID和OSNAP）以及基于观测的AMOC重建来评估在最先进的S2D预测系统中预测AMOC的技能。它将评估有助于技能及其跨模型一致性的过程，并使用新的模拟来更好地理解不同过程在驱动S2D时间尺度上观察到的变率方面的相对作用。此外，新的大集合模拟将用于量化外部强迫在驱动AMOC变率和变化中的作用。最后，有了这一新的认识，它将确定是否可以通过物理一致的统计校准来改善AMOC和AMOC相关气候影响的S2D预测，从而减少大气环流预测中的信噪比问题。这些新知识可能为未来预测系统的发展提供信息，并将直接提供给国际协调活动，如WCRP的十年气候预测项目（DCPP）及其解释和预测地球系统变化的灯塔活动（EPESC）。改进和更好地理解气候预测将为整个社会带来重大利益。在这项工作中获得的知识将通过支持美国大学社区的CESM地球系统预测工作组公布。这些发现可能会影响关注气候变化和预测、气候预测、海洋模拟和观测海洋学的不同研究团体。NCAR的早期职业科学家（博士后）将受益于与国际专家团队合作的机会。这项工作的预期智力进步包括：1)澄清了最先进的初始化预测系统在根据一套可用的观测基准进行验证时预测AMOC及其组成电流的当前能力；2)阐明在熟练系统中起作用的关键可预测性机制及其时间尺度依赖性；3)提高了对AMOC预测是否以及如何转化为对大西洋扇区气候影响的准确预测的认识；4)更复杂的AMOC变化归因；5)评估利用新的预报校准技术改进S2D AMOC和相关影响预测的潜力。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。

This is a project jointly funded by the National Science Foundation’s Directorate for Geosciences (NSF/GEO) and the National Environment Research Council (NERC) of the United Kingdom (UK) via the NSF/GEO-NERC Lead Agency Agreement. This Agreement allows a single joint US/UK proposal to be submitted and peer-reviewed by the Agency whose investigator has the largest proportion of the budget. Upon successful joint determination of an award recommendation, each Agency funds the proportion of the budget that supports scientists at institutions in their respective countries.This project aims to advance understanding of AMOC (Atlantic Meridional Overturning Circulation) predictability. The overarching objective of this international collaboration is to quantify, understand, and improve our capacity to predict the AMOC and its climate impacts on seasonal-to-decadal (S2D) timescales. It will utilize AMOC observations (RAPID and OSNAP) as well as observation-based AMOC reconstructions to assess the skill in predicting the AMOC in state-of-the-art S2D prediction systems. It will evaluate the processes that contribute to skill and their consistency across models and use new simulations to better understand the relative roles of different processes in driving observed variability on S2D timescales. Additionally, new large- ensemble simulations will be used to quantify the role of external forcing in driving AMOC variability and change. Finally, with this new understanding, it will determine whether S2D predictions of AMOC and AMOC-related climate impacts can be improved through physically-consistent statistical calibrations that reduce the signal-to-noise issues in predictions of atmospheric circulation. The new knowledge may inform future prediction system development and will feed directly into international coordinated activities such as WCRP’s Decadal Climate Prediction Project (DCPP) and its lighthouse activity on Explaining and Predicting Earth System Change (EPESC). Improved and better understood climate predictions will deliver significant benefits to society as a whole. The knowledge gained in this effort will be promulgated through the CESM Earth System Prediction Working Group that supports the US university community. The findings will likely influence diverse research communities focused on climate change and projection, climate prediction, ocean modeling, and observational oceanography. An early career scientist (postdoc) at NCAR will benefit from the opportunity to work with an international team of experts.The expected intellectual advancements from this work include: 1) clarification of the current capacity of state-of-the-art initialized prediction systems to predict AMOC and its constituent currents when verified against a suite of available observational benchmarks; 2) elucidation of the key predictability mechanisms at work in skillful systems and their time scale dependence; 3) improved understanding of whether and how skillful AMOC prediction translates into skillful prediction of Atlantic sector climate impacts; 4) more sophisticated attribution of past AMOC change; and 5) assessment of the potential to improve S2D AMOC and associated impacts predictions using new forecast calibration techniques.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.