Intercomparison of methods of coupling between convection and large-scale circulation: 1. Comparison over uniform surface conditions.
Intercomparison of methods of coupling between convection and large-scale circulation: 1. Comparison over uniform surface conditions.
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对流与大范围环流耦合方法对比： 1、均匀地表条件下的对比。
DOI：
10.1002/2015ms000468
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发表时间：
2015-12
影响因子：
6.8
通讯作者：
van Ulft, L.
中科院分区：
文献类型：
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作者：
Daleu, C. L.;Plant, R. S.;Woolnough, S. J.;Sessions, S.;Herman, M. J.;Sobel, A.;Wang, S.;Kim, D.;Cheng, A.;Bellon, G.;Peyrille, P.;Ferry, F.;Siebesma, P.;van Ulft, L.
关键词：
作为国际比较项目的一部分，在弱温度梯度（WTG）方法和阻尼重力波（DGW）方法下运行了一套单柱模型（scm）和云分辨模型（crm）。对于每个模型，WTG或DGW方法的实现都涉及到一个模拟柱，该柱耦合到一个参考状态，该参考状态由同一模型在辐射-对流平衡中获得的剖面定义。模拟柱具有与参考状态相同的表面条件，并使用参考状态的轮廓进行初始化。我们系统地比较了WTG方法和DGW方法在一致实施下不同模型的行为，系统地比较了WTG和DGW方法在不同物理和数值模型中的表现。crm和scm在WTG和DGW方法下都会产生各种各样的行为。一些模式再现了参考状态，而另一些模式则维持了一个大尺度环流，与参考状态的值相比，这种环流导致的降水要么大大减少，要么大大增加。CRMs在降水和环流强度之间表现出相当的线性关系。scm比crm表现出更广泛的行为。在WTG方法下，一些SCMs产生零降水。在单个SCM中，DGW模拟和相应的WTG模拟可以产生不同的有符号循环。当初始化为干燥对流层时，DGW模拟总是得到沉淀平衡状态。在一些WTG模拟中，对初始湿度条件最敏感的是多个稳定平衡，对应于初始化为干燥时的干燥平衡状态或初始化为潮湿时的沉淀平衡状态。对于较高的海温，在更多的WTG模拟中可以看到多重平衡。在某些模型中，多重平衡的存在对WTG计算中的某些参数很敏感。在WTG和DGW方法下的SCMs表现出比CRMs更广泛的行为，DGW模拟总是导致沉淀平衡状态，一些WTG模拟中存在多个稳定平衡
As part of an international intercomparison project, a set of single‐column models (SCMs) and cloud‐resolving models (CRMs) are run under the weak‐temperature gradient (WTG) method and the damped gravity wave (DGW) method. For each model, the implementation of the WTG or DGW method involves a simulated column which is coupled to a reference state defined with profiles obtained from the same model in radiative‐convective equilibrium. The simulated column has the same surface conditions as the reference state and is initialized with profiles from the reference state. We performed systematic comparison of the behavior of different models under a consistent implementation of the WTG method and the DGW method and systematic comparison of the WTG and DGW methods in models with different physics and numerics. CRMs and SCMs produce a variety of behaviors under both WTG and DGW methods. Some of the models reproduce the reference state while others sustain a large‐scale circulation which results in either substantially lower or higher precipitation compared to the value of the reference state. CRMs show a fairly linear relationship between precipitation and circulation strength. SCMs display a wider range of behaviors than CRMs. Some SCMs under the WTG method produce zero precipitation. Within an individual SCM, a DGW simulation and a corresponding WTG simulation can produce different signed circulation. When initialized with a dry troposphere, DGW simulations always result in a precipitating equilibrium state. The greatest sensitivities to the initial moisture conditions occur for multiple stable equilibria in some WTG simulations, corresponding to either a dry equilibrium state when initialized as dry or a precipitating equilibrium state when initialized as moist. Multiple equilibria are seen in more WTG simulations for higher SST. In some models, the existence of multiple equilibria is sensitive to some parameters in the WTG calculations. SCMs under both WTG and DGW methods display a much wider range of behaviors compared to CRMs DGW simulations always result in a precipitating equilibrium states Multiple stable equilibria exist in some WTG simulations