Collaborative Research: "EaSM-3": The Role of Ocean Eddies in Decadal Prediction

合作研究：“EaSM-3”：海洋涡流在年代际预测中的作用

• 批准号: 1419569
• 负责人: Benjamin Kirtman
• 金额: $ 160万
• 依托单位: University of Miami
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-07-15 至 2020-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1419569&HistoricalAwards=false
• 关键词: Collaborative; Research; EaSM; Role; Ocean

There is a growing demand for environmental predictions that include a broader range of space and time scales and that include a more complete representation of weather and climate processes. Meeting this demand necessitates a unified approach that challenges the traditional boundaries between weather and climate science, and requires a more integrated approach with much higher spatial resolution models that resolve important dynamical processes and their interactions. Estimates of predictability are likely to be sensitive to the range of processes and phenomena captured by these models. This project seeks to provide a comprehensive assessment of how ocean eddies affect decadal predictability. One of the key questions this project asks is, do prediction systems actually need to initialize individual ocean eddies or is simply including ocean eddies in the prediction system sufficient? Answering this question has profound implications in the design of decadal prediction systems. This project will contribute to workforce development through the education of a graduate student in important climate variability and change problems, and the mentoring of a post-doctoral researcher. The decadal prediction and climate services community will be advised regarding how ocean eddies impact decadal predictability and how to initialize them in eddy resolving models. The new capacity for high-resolution assimilation within the freely accessible Community Earth System Model (CESM) and Data Assimilation Research Testbed (DART) modeling frameworks will be available to the CESM climate modeling community. More broadly, any model that interfaces with the DART ensemble assimilation system can leverage the data assimilation infrastructure advances and tool development that will be developed under this project. Ocean eddy-resolving simulations, data assimilation products, predictability and experimental prediction results that are of interest to the broader climate community will be also made readily available.This research project is based on the hypothesis that the dynamic and physical process associated with ocean eddies and the accompanying interactions with the atmosphere have a large and robust impact on decadal predictability. The proposed research seeks to quantify this effect through diagnostic predictability research by analyzing long eddy resolving simulations and prognostic "perfect" model predictability experiments. Tools and capabilities that are necessary to initialize the ocean component of coupled models at eddy resolving resolutions will be developed. The new eddy resolving data assimilation system will be evaluated through experimental prediction. The project also seeks to develop a data assimilation system appropriate for initializing decadal prediction at ocean eddy-resolving scales. The current ensemble-based ocean data assimilation method available at eddy-permitting resolution will be applied to the eddy-resolving model. To support tuning the new high-resolution data assimilation system, novel tools for estimating the resolution-dependent observational error statistics used in the assimilation will be developed. The specification of resolution-dependent observational error statistics is of enormous importance for data assimilation, and tools to support this are currently unavailable. The limitations of the high-resolution ocean data assimilation system will be assessed in terms of its computational cost and its efficacy at constraining the eddy field, and the project will develop strategies for addressing these limitations that are aligned with the needs of decadal prediction that are identified as part of the decadal predictability research. Finally, the data assimilation system will be implemented at eddy-resolving scales during the data-rich years of 2006-present, and evaluated with experimental predictions.

对包括更大范围的空间和时间尺度以及包括更完整的天气和气候过程表示的环境预报的需求越来越大。满足这一需求需要一种统一的方法来挑战天气和气候科学之间的传统界限，并需要一种更综合的方法和更高的空间分辨率模型，以解决重要的动力过程及其相互作用。对可预测性的估计很可能对这些模型捕捉到的过程和现象的范围很敏感。这个项目试图对海洋涡旋如何影响十年可预测性提供一个全面的评估。这个项目提出的一个关键问题是，预报系统是否真的需要初始化单独的海洋漩涡，或者仅仅在预报系统中包括海洋漩涡就足够了？回答这个问题对十年预报系统的设计具有深远的影响。该项目将通过对研究生进行有关重要气候变化和变化问题的教育，以及对博士后研究人员的指导，来促进劳动力发展。将向十年预报和气候服务界提供关于海洋涡旋如何影响十年可预测性以及如何在涡旋解析模式中对其进行初始化的建议。可自由使用的社区地球系统模式(CESM)和数据同化研究试验床(DART)模拟框架内的高分辨率同化新能力将提供给CESM气候模型界。更广泛地说，任何与DART集合同化系统对接的模型都可以利用将在该项目下开发的数据同化基础设施的进展和工具开发。海洋涡旋分辨率模拟、数据同化产品、可预报性和实验预测结果也将随时可用。这项研究项目基于与海洋涡旋相关的动力和物理过程以及伴随而来的与大气的相互作用对十年可预报性有巨大而强大的影响这一假设。这项拟议的研究试图通过诊断可预测性研究来量化这种影响，方法是分析长涡分辨模拟和预测“完美”模式可预测性实验。将开发在涡旋分辨率下初始化耦合模式海洋部分所必需的工具和能力。新的涡旋分辨资料同化系统将通过试验预报进行评估。该项目还试图开发一个数据同化系统，用于在海洋涡旋分辨率尺度上初始化年代际预报。涡旋分辨模式将采用目前在涡旋允许分辨率下可用的基于集合的海洋数据同化方法。为支持调整新的高分辨率数据同化系统，将开发新的工具，用于估计同化中使用的依赖分辨率的观测误差统计数据。与分辨率有关的观测误差统计的规范对数据同化非常重要，目前还没有支持这一点的工具。高分辨率海洋数据同化系统的局限性将从其计算成本和其限制涡旋场的效力方面进行评估，该项目将制定战略，以解决这些局限性，使之与十年可预测性研究中确定的年代际预测的需要相一致。最后，数据同化系统将在2006年至今数据丰富的年份在涡旋分辨率尺度上实施，并用实验预测进行评估。