Collaborative Research: An eddy-permitting Arctic & Sub-Polar State Estimate for climate research

合作研究：允许涡流的北极

• 批准号: 1022733
• 负责人: Rui Ponte
• 金额: $ 45.53万
• 依托单位: Atmospheric and Environmental Research Inc
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2010
• 资助国家: 美国
• 起止时间: 2010-09-15 至 2014-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1022733&HistoricalAwards=false
• 关键词: Collaborative; Research; eddy; permitting; Arctic

Funds are provided to produce an eddy-permitting Arctic and sub-polar NorthAtlantic state estimate (ASTE) for climate research, using basic tools developed within the Estimating the Circulation and Climate of the Ocean (ECCO) consortium. The coupled ocean/sea-ice general circulation model (MITgcm) will be constrained by as many ocean and sea-ice observations as available and practical. The target period is from 1992 to present. The fit will be achieved through minimization of a least-squares misfit function (adjoint or Lagrange Multiplier method). The coupled ocean/sea-ice adjoint model has been generated by means of automatic differentiation (AD). A similar effort has been successfully accomplished with the production of the Southern Ocean State Estimate (SOSE). The domain of the ASTE covers the Atlantic northward of 26 N and the entire Arctic, with the exception of the Pacific sector southward of Bering Strait (66 N). The horizontal resolution is 7 to 12 km with 50 vertical levels. The control space comprises the initial conditions of the coupled ocean/sea-ice state, the time-varying surface atmospheric state, time-varying open boundary conditions, and spatially varying model parameters.The observational backbone used initially for the ocean consists of: sea surface height from satellite altimetry, daily satellite SST, mean geoid and time-varying bottom pressure from satellite gravity and moorings, Argo float profiles, hydrographic data from WOCE and PHC, available mooring arrays such as Line-W and RAPID/MOCHA, and current meters available via AON/CADIS, PANGEAE (ASOF), and NSIDC (SCICEX). Sea-ice satellite observations used initially will comprise: daily ice concentration, ice drift velocities from passive microwave radiometry, scatterometry, and SAR imagery. In-situ under-ice data will include ice-tethered profilers, ice mass balance buoys, ice draft from submarine-borne upward looking sonar, as well as various buoy and mooring data from the IABP and AON/CADIS archives. Extension to other data sources includes tests of satellite retrievals of ice thickness or freeboard data from combined radar and laser altimetry.Their approach offers strict dynamical consistency of the computed state estimate over the entire integration period, enabling exact time-varying budget calculations relevant for climate studies, such as the assessment of circulation shifts and their associated lateral heat and freshwater changes on seasonal and longer time scales. In this sense, the product differs significantly from what in the atmospheric context are called ?re-analysis? products. Another novelty of the product is its combined treatment of the Arctic and the subpolar gyre, and the synthesis of all available data types. Initial science foci will be on the connection between deep water formation processes and the Atlantic meridional overturning, the freshwater input at high latitudes and its pathways, and the interaction between Atlantic Water, Arctic halocline formation, and sea-ice.

提供资金，利用在估计海洋环流和气候(ECCO)联盟内开发的基本工具，为气候研究编制允许涡流的北极和亚极地北大西洋状态估计(ASTE)。海洋/海冰耦合环流模式(MITgCM)将受到尽可能多的海洋和海冰观测的制约。目标期为1992年至今。拟合将通过最小化最小二乘失配函数(伴随或拉格朗日乘子法)来实现。利用自动微分(AD)方法建立了海/海-冰耦合伴随模式。通过编制《南大洋状况估计数》，也成功地完成了类似的工作。除白令海峡(北纬66度)以南的太平洋部分外，东经的范围包括北纬26度以北的大西洋和整个北极。水平分辨率为7-12公里，50个垂直水平。控制空间包括海洋/海冰耦合状态的初始条件、时变的地表大气状态、时变的开放边界条件和空间变化的模式参数。最初用于海洋的观测骨干包括：卫星测高的海面高度、每日卫星SST、卫星重力和系泊的平均大地水准面和随时间变化的海底压力、ARGO浮标剖面、来自WOCE和PHC的水文数据、可用的系泊阵列(如Line-W和RAPID/MOCHA)以及通过AON/CADIS、PANGEAE(ASOF)和NSIDC(SCICEX)获得的海流计。最初使用的海冰卫星观测将包括：每日冰浓度、被动微波辐射测量、散射测量和合成孔径雷达图像。现场冰下数据将包括冰系留剖面仪、冰块平衡浮标、来自潜艇上俯视声纳的冰吃水，以及来自IABP和Aon/Cadis档案的各种浮标和系泊数据。对其他数据来源的扩展包括对卫星从雷达和激光时刻表中提取冰层厚度或干板数据的测试。他们的方法在整个积分期间对计算的状态估计提供了严格的动态一致性，使与气候研究相关的准确的时变预算计算成为可能，例如评估环流变化及其在季节性和更长时间尺度上的相关横向热量和淡水变化。从这个意义上说，产品与大气环境下的产品有很大的不同？重新分析？产品。该产品的另一个新颖性是它对北极和亚极地环流的综合处理，并综合了所有可用的数据类型。最初的科学重点将是深水形成过程与大西洋经向翻转之间的联系，高纬度的淡水输入及其途径，以及大西洋水、北极盐跃层形成和海冰之间的相互作用。