A simple dynamical model of cumulus convection for data assimilation research
A simple dynamical model of cumulus convection for data assimilation research
复制标题
用于资料同化研究的简单积云对流动力学模型
DOI：
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
G. Craig
中科院分区：
文献类型：
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作者：
Michael Würsch;G. Craig
已开发了一个简化的积云对流模式，目的是为开发对流尺度数据同化方法提供一个计算成本低但在物理上合理的环境。描述了重力波、条件不稳定和降水形成等关键过程，并选取参数值来再现积云最重要的空间和时间尺度。该模式再现了孤立对流风暴的经典生命周期。当提供低幅度噪声源以触发对流时，该模式产生了统计上稳定的状态，其云大小和云间距分布类似于使用云分解模式进行辐射-对流平衡模拟时的结果。结果还显示了由气流越过地形障碍物引发的对流，根据风速的不同，发现了两个区域，对流被困在山上，或向下游传播。该模式具有风和雨的预报变量，可用于计算数据同化实验的合成观测值。
A simplified model for cumulus convection has been developed, with the aim of providing a computationally inexpensive, but physically plausible, environment for developing methods for convective-scale data assimilation. Key processes, including gravity waves, conditional instability and precipitation formation, are represented, and parameter values are chosen to reproduce the most important space and time scales of cumulus clouds. The model is shown to reproduce the classic life cycle of an isolated convective storm. When provided with a low amplitude noise source to trigger convection, the model produces a statistically steady state with cloud size and cloud spacing distributions similar to those found in radiative-convective equilibrium simulations using a cloud resolving model. Results are also shown for convection triggered by flow over an orgraphic obstacle, where depending on the wind speed two regimes are found with convection trapped over the mountain, or propagating downstream. The model features prognostic variables for wind and rain that can be used to compute synthetic observations for data assimilation experiments.