Development and optimization of the IPM MM5 GPS slant path 4DVAR system
Development and optimization of the IPM MM5 GPS slant path 4DVAR system
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DOI：
10.1127/0941-2948/2008/0339
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发表时间：
2008-12
影响因子：
1.2
通讯作者：
F. Zus;Matthias Grzeschik;H. Bauer;V. Wulfmeyer;G. Dick;M. Bender
中科院分区：
文献类型：
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作者：
F. Zus;Matthias Grzeschik;H. Bauer;V. Wulfmeyer;G. Dick;M. Bender
本文介绍了常规的4维变分同化的全球定位系统倾斜总延迟（STD）数据的工具的开发框架中的MM5系统的物理和气象研究所的霍恩海姆大学。引入了Slant Total Delay前向算子，它允许在消息传递接口环境中进行模型验证和同化。进行了一个实验，突出了准确的模式物理在变分同化系统的重要性。我们证明了模型减去STD数据的观测统计量主要取决于对流方案和水平扩散的实施。对现有的非线性、切线性和伴随模型进行了一系列改进。这些措施包括改进的水平扩散方案和实施的Grell积云对流方案，以消除观测到的系统趋势的模式减去观测统计的STD数据和降水在山区地形。利用改进的MM5变分同化系统进行的第一次同化试验显示了良好的效果。
This article describes the development of tools for routine 4-dimensional variational data assimilation of Global Positioning System Slant Total Delay (STD) data in the framework of the MM5 system at the Institute of Physics and Meteorology of the University of Hohenheim. The Slant Total Delay forward operator is introduced which allows model validation and the assimilation in the Message-Passing Interface environment. An experiment is conducted which highlights the importance of accurate model physics in the variational assimilation system. We demonstrate that the model minus observation statistics of STD data crucially depends on the convection scheme and the implementation of horizontal diffusion. A set of modifications to the existing non linear, tangent linear and adjoint model is presented. These include an improvement of the horizontal diffusion scheme and the implementation of the Grell cumulus convective scheme in order to eliminate the observed systematic tendency in the model minus observation statistics of the STD data and precipitation in mountainous terrain. A first assimilation experiment with the improved MM5 variational assimilation system shows promising results.