Recent development of the Met Office operational ocean forecasting system: an overview and assessment of the new Global FOAM forecasts
Recent development of the Met Office operational ocean forecasting system: an overview and assessment of the new Global FOAM forecasts
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DOI：
10.5194/gmd-7-2613-2014
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发表时间：
2014-01-01
影响因子：
5.1
通讯作者：
Storkey, D.
中科院分区：
文献类型：
--
作者：
Blockley, E. W.;Martin, M. J.;Storkey, D.
海洋同化预报模式（FOAM）是英国气象局每天运行的海洋分析和预报系统。FOAM使用NEMO（欧洲海洋模型核心）海洋模型作为其动力核心，在深海和沿海大陆架海域提供建模能力。FOAM深海套件以1/4度的分辨率为全球海洋提供海洋示踪剂、洋流和海冰的分析和7天预测。在48小时的观测窗口内，每天由foama同化卫星和现场观测到的温度、盐度、海平面异常和海冰浓度。泡沫深海配置最近经历了一次重大升级，其中包括实施一种新的变分，在适当时间首次猜测（FGAT） 3D-Var同化方案（NEMOVAR）；耦合到一个不同的、多厚度类别的海冰模型（CICE）；采用协调海冰参考实验（CORE）体积公式确定地表边界条件；并提高了全球模型的垂直分辨率。本文介绍了新的泡沫深海系统，并详细介绍了最近的变化。结果来自全球FOAM配置的2年再分析整合，包括对短期海洋预报精度的评估。与以前的泡沫系统和非同化泡沫系统进行了比较。评估显示，新系统对近地表海洋和海冰区有相当大的改善。然而，地下示踪场和赤道地区的示踪场有一些退化，这突出了未来需要重点改进的具体领域。
The Forecast Ocean Assimilation Model (FOAM) is an operational ocean analysis and forecast system run daily at the Met Office. FOAM provides modelling capability in both deep ocean and coastal shelf sea regimes using the NEMO (Nucleus for European Modelling of the Ocean) ocean model as its dynamical core. The FOAM Deep Ocean suite produces analyses and 7-day forecasts of ocean tracers, currents and sea ice for the global ocean at 1/4 degrees resolution. Satellite and in situ observations of temperature, salinity, sea level anomaly and sea ice concentration are assimilated by FOAMeach day over a 48 h observation window. The FOAM Deep Ocean configurations have recently undergone a major upgrade which has involved the implementation of a new variational, first guess at appropriate time (FGAT) 3D-Var, assimilation scheme (NEMOVAR); coupling to a different, multi-thickness-category, sea ice model (CICE); the use of coordinated ocean-ice reference experiment (CORE) bulk formulae to specify the surface boundary condition; and an increased vertical resolution for the global model.In this paper the new FOAM Deep Ocean system is introduced and details of the recent changes are provided. Results are presented from 2-year reanalysis integrations of the Global FOAM configuration including an assessment of short-range ocean forecast accuracy. Comparisons are made with both the previous FOAM system and a non-assimilative FOAM system. Assessments reveal considerable improvements in the new system to the near-surface ocean and sea ice fields. However there is some degradation to sub-surface tracer fields and in equatorial regions which highlights specific areas upon which to focus future improvements.