On discretization error and its control in variational data assimilation
On discretization error and its control in variational data assimilation
复制标题
变分资料同化中的离散化误差及其控制
DOI：
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发表时间：
2008
期刊：
影响因子：
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通讯作者：
Yonghui Wu
中科院分区：
文献类型：
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作者：
D. Furbish;M. Hussaini;F. Le Dimet;Pierre Ngnepieba;Yonghui Wu
在四维变分资料同化(4D-Var)中，模式方程被视为对优化问题的强约束。在现实中，该模型不能准确地反映系统的行为，并且由于物理近似、离散化、物理参数的可变性以及初始条件和边界条件的不准确而产生误差。由于直接测量和将状态(模型)空间映射到观测空间或反之亦然，观测中的误差也是固有的。这项工作的目的是定义这些误差，特别是离散化误差和投影误差，并形成一个典型问题，以研究它们对数据同化过程和由此产生的预测的质量的影响。
In four-dimensional variational data assimilation (4D-Var), the model equations are treated as strong constraints on an optimization problem. In reality, the model does not represent the system behaviour exactly and errors arise due to physical approximations, discretization, variability of physical parameters, and inaccuracy of initial and boundary conditions. Errors are also inherent in observation due to inaccuracies in the direct measurement and mapping of the state (model) space onto the observational space or vice versa. The purpose of this work is to define these errors, in particular the discretization and projection errors, and to formulate a canonical problem to study their impact on the quality of the data assimilation process and resulting predictions.