Collaborative Research: Thermodynamic and Dynamic Drivers of the Arctic Sea Ice Mass Budget at MOSAiC

海冰的能量通量，以及在时间和空间上控制它们的过程，构成了目前北极中部系统模型中一些最大的不确定性，并且很可能随着海冰变薄而变化。该项目将进行观察，以提供模型开发人员需要的信息类型，以表示紧急的北极过程。这些观测将是在一个明确定义的网络中收集的第一套综合的、耦合的大气-冰-海洋能量和动量通量测量。他们将通过耦合模型的协同使用，实现对冰热力学和动力学的基于过程的理解。多学科漂流观测站的北极气候研究（马赛克）考察是一个巨大的机会，利用大量的美国和国际投资马赛克的动机是不断变化的北极系统和减少的海冰，以及它们对全球气候系统和众多利益相关者的重大影响。该倡议旨在通过北极中部漂流站的密集全年观测和协调的多尺度建模，解决北极系统中耦合大气-冰-海洋过程模式表示的主要缺陷。该项目将详细研究海冰热力学和动力过程的相互作用，以及它们如何在一整年内控制冰的状态。该项目将需要在北极海冰中心安装一个由五个节点组成的观测阵列，每个节点相距约15公里，每个节点都有连续测量上层海洋和下层大气状态的系统，从海洋和大气到冰的热量和动量通量，以及冰的热力学状态和质量平衡。一个位置浮标网将用于测量整个观测区域的冰的运动和变形。区域耦合系统模型模拟将为过程理解提供综合观测信息的手段。这些工具将共同用于建立全面的海冰能量、上层海洋热量和海冰动量预算，研究这些在所有季节中如何在空间和时间上共同变化，并开发多个关键参数之间的时间演变过程关系。他们将使用详细的观测和耦合的区域模式来研究能量传递过程（热力学）如何在分季节到季节的时间尺度上受到海冰变形（动力学）的影响，他们将利用一整年准操作的10天海冰预报来评估与动力和热力学过程关系相关的海冰可预测性。改进的预测模型是解决与北极变化和海冰减少有关的主要社会需求的重要手段。该项目将为模型开发人员和国际专家所要求的模型开发提供一个观察和基于过程的基础。此外，它将深入了解海冰可预测性的来源，这将有助于限制未来改进海冰模型的研究途径。这些观测将使一系列广泛的耦合系统研究成为可能，远远超出了拟议项目的范围，从而影响北极物理、生物和生物地球化学系统的其他方面的研究。此外，该项目将支持自主海洋和大气通量测量的发展，这将有助于填补北极观测网络的关键空白。围绕该项目的研究主题开发的教育内容将支持学生学习北极系统的物理学，并使更广泛的科学推广工作成为可能。

Energy fluxes to the sea ice, and the processes that control them in time and space, comprise some of the largest uncertainties in current models of the central Arctic system and are likely changing as the sea ice thins. This project will make observations to provide the type of information that model developers need for representing emergent Arctic processes. These observations will be the first set of comprehensive, coupled atmosphere-ice-ocean energy and momentum flux measurements collected within a well-defined network. They will enable a process-based understanding of ice thermodynamics and dynamics via synergistic use of a coupled model. The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition is a tremendous opportunity to leverage large US and international investments MOSAiC is motivated by the changing Arctic system and declining sea ice, and their significant implications for the global climate system and numerous stakeholders. The initiative seeks to address leading deficiencies in model representation of coupled, atmosphere-ice-ocean processes in the Arctic system through intensive, year-round observations from a drifting station in the central Arctic and coordinated multi-scale modeling. This project will examine the detailed interplay of sea-ice thermodynamic and dynamic processes and how they control the state of the ice over a full year. This project will entail an observational array of five nodes installed at approximately 15 km separation in the central Arctic sea ice, each of which has systems to measure continuously the states of the upper ocean and lower atmosphere, the heat and momentum fluxes from the ocean and atmosphere to the ice, and the ice thermodynamic state and mass balance. A network of position buoys will be used to measure ice movement and deformation across the observing domain. Regional, coupled-system model simulations will provide the means to synthesize observational information towards process understanding. Together these tools will be used to build comprehensive sea ice energy, upper ocean heat, and sea-ice momentum budgets, examine how these co-vary in space and time over all seasons, and develop temporally-evolving process relationships among multiple key parameters. They will use the detailed observations and coupled regional model to examine how energy transfer processes (thermodynamics) are influenced by sea-ice deformation (dynamics) on sub-seasonal to seasonal time scales, and they will assess sea-ice predictability related to dynamic and thermodynamic process relationships, using a full year of quasi-operational, 10-day sea-ice forecasts. Improved predictive models are an important means for addressing major societal needs related to Arctic change and declining sea ice. The project will provide an observational and process-based foundation for model development that has been called for by model developers and international experts. Moreover, it will offer insight into the sources of sea ice predictability, which will help to constrain future research pathways for improved sea ice models. The observations will enable a wide array of coupled system research that reaches well beyond the proposed project to impact research on other aspects of the Arctic physical, biological, and biogeochemical systems. Moreover, this project will support development towards autonomous ocean and atmospheric flux measurements that will help fill critical gaps in the Arctic observing network. Educational content developed around the project's research themes will support student learning on the physics of the Arctic system and enable broader scientific outreach efforts.