EASM-3: Collaborative Research: Quantifying Predictability Limits, Uncertainties, Mechanisms, and Regional Impacts of Pacific Decadal Climate Variability

太平洋地区的气候在十年时间尺度上有所不同，但控制这些长期气候变化的机制仍然不清楚。如果能够更好地了解这些机制，那么就可以更准确地评估与在这些时间尺度上做出气候预测相关的不确定性。美国对太平洋的年代际变化特别感兴趣，因为它对美国西部的下游影响以及对阿拉斯加气候的直接影响。该项目利用气候模型和现代统计工具的层次结构，解决太平洋气候系统年代际模式的可预测性界限、机制和区域影响这一根本问题。该项目的结果将对评估环境的长期变化如何推动重要经济变量的变化，如降雨、土壤湿度、降雪量、温度以及海洋温度、洋流和海平面的变化，从而影响美国西海岸和亚洲边缘海的渔业、农业和沿海基础设施具有重要意义。该项目开发的工具应可转让给也表现出十年变化的其他全球部门。项目团队将指导研究生和博士后，他们的教育经验将包括跨学科接触海洋科学、大气科学和社会影响，这在这一背景下将是独一无二的。社区外展将包括在公共论坛上的讲座和教育演示，指导K-12学生，教育基层气候行动组织，通知媒体，并将研究结果发布在网页上。显然，我们在理解是什么控制了太平洋年代际气候变化，什么限制了流动的可预测性，以及在陆地和海洋的区域影响中可能有用的实用技能方面存在很大差距。项目组建议开展一项协调一致的研究工作，以更好地了解太平洋年代际变化的基本物理动态，并评估太平洋年代际变化的可预测性及其不确定性和实用价值。这项研究的重点是社区地球系统模型(CESM)，该模型具有大量的归档运行存储库，并辅之以有针对性的可预测性实验。分析的重点是使用复杂的统计模型(线性逆模型)来确定变量之间的统计关系，诊断物理过程，并隔离潜在的可预测的流组件。它还涉及使用区域大气-海洋耦合以及非耦合海洋和大气模式，以加强对区域反应及其在预报中实际使用的潜力的了解。该项目汇集了擅长开发十年气候诊断、进行统计和动力预测、执行区域耦合气候缩小尺度和区域高分辨率海洋建模的科学家。

Climate in the Pacific region varies on decadal timescales, but the mechanisms that control these long-term climate variations are still unclear. If the mechanisms can be better understood, then the uncertainties associated with making climate predictions on these timescales can be assessed more accurately. Decadal variability over the Pacific is of particular interest in the United States due to its downstream influence over the western United States and its direct influence on climate in Alaska. This project addresses the fundamental question of what are the predictability limits, mechanisms, and regional impacts for decadal modes of the Pacific climate system using a hierarchy of climate models and modern statistical tools. The results of this project will be important in assessing how long-term changes in the environment drive changes in economically important variables such as rainfall, soil moisture, snowfall, temperatures, as well as oceanic temperatures, currents and sea levels, which impacts fisheries, agriculture, and coastal infrastructure along the U.S. West Coast and Asian Marginal Seas. The tools developed in this project should be transferable to other global sectors that also exhibit decadal variability. The project team will mentor graduate students and post-docs, whose educational experiences will include cross-disciplinary exposure to ocean science, atmospheric science, and societal impacts that will be unique in this context. Community outreach will include lectures and educational presentations in public forums, mentoring K-12 students, educating grass-roots climate action organizations, informing the media, and posting research results on web pages.There is clearly a large gap in our understanding of what controls Pacific decadal climate variability, what limits the predictability of the flows, and what practical skill might be useful in regional impacts on land and in the ocean. The project team proposes a coordinated research effort to better understand the basic physical dynamics of Pacific decadal variability and assess the skill of Pacific decadal predictability, along with its uncertainties and practical value. The research focuses on Community Earth System Model (CESM), with its vast repository of archived runs supplemented with targeted predictability experiments. The analysis focuses on using sophisticated statistical models (Linear Inverse Models) to identify statistical relations among variables, diagnose physical processes, and isolate potentially predictable components of the flows. It also involves using regional coupled atmosphere-ocean, along with uncoupled ocean and atmosphere models, to enhance the understanding of regional response and its potential for practical use in forecasting. The project brings together scientists skilled with developing decadal climate diagnostics, making both statistical and dynamical predictions, and executing regional coupled climate downscaling and regional high-resolution ocean modeling.