Implementation of new diffusion/filtering operators in the CAM-FV dynamical core
Implementation of new diffusion/filtering operators in the CAM-FV dynamical core
复制标题
在 CAM-FV 动力核心中实施新的扩散/过滤算子
DOI：
10.1177/1094342011410088
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
R. Neale
中科院分区：
文献类型：
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作者：
P. Lauritzen;A. Mirin;J. Truesdale;K. Raeder;Jeffrey L. Anderson;J. Bacmeister;R. Neale
两个新的过滤/扩散算子已被实现在社区大气模式有限体积动力学核心（CAM-FV）。首先，一个四阶发散阻尼算子已经被添加到可选地取代传统上使用的二阶版本。这提供了发散模式的更多尺度选择性耗散，如果没有适当地阻尼，发散模式可以在CAM-FV中产生网格尺度噪声。例如，使用CAM-FV DART（数据同化研究试验台）的数据同化运行揭示了网格尺度下潜在的噪声问题，可以使用高阶发散阻尼显着缓解。第二，一个“拉普拉斯”型阻尼运营商已被实施，以增加显式的动量耗散在顶部的大气海绵层。这有助于控制在超高分辨率CAM-FV模拟中观察到的过多的极地夜间急流。本文沿着了独立CAM-FV和CAM-FV DART的结果，并详细介绍了新算子的实现。
Two new filtering/diffusion operators have been implemented in the Community Atmosphere Model finite-volume dynamical core (CAM-FV). First, a fourth-order divergence damping operator has been added to optionally replace the second-order version that has traditionally been used. This provides more scale selective dissipation of divergent modes that can generate grid-scale noise in CAM-FV if not damped properly. For example, data assimilation runs using CAM-FV DART (Data Assimilation Research Testbed) have revealed potential noise problems at the grid scale that can be alleviated significantly using higher-order divergence damping. Second, a ‘Laplacian’-type damping operator has been implemented to increase the explicit momentum dissipation in the top-of-atmosphere sponge layers. This helps control the excessive polar night jets that have been observed in ultra-high-resolution CAM-FV simulations. Results from stand-alone CAM-FV and CAM-FV DART are presented in this paper along with details on the implementation of the new operators.