On the use of a predictor–corrector scheme to couple the dynamics with the physical parametrizations in the ECMWF model
On the use of a predictor–corrector scheme to couple the dynamics with the physical parametrizations in the ECMWF model
复制标题
关于使用预测校正方案将 ECMWF 模型中的动力学与物理参数化耦合
DOI：
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发表时间：
2003
期刊：
影响因子：
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通讯作者：
D. Salmond
中科院分区：
文献类型：
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作者：
M. Cullen;D. Salmond
将解析动力学的时间积分与大气模型中的参数化过程耦合的方法是一个活跃的开发领域。许多中心对其模型中耦合方法的变化表现出强烈的敏感性。欧洲中期天气预报中心最近推出了一种修订后的耦合方法，该方法具有显着的预测效益。理论上，由于参数化中表示的时间尺度的混合，很难建立最佳方法。隐式方法非常适合实现不同过程之间的耦合，但由于大多数参数化方案中存在非线性切换，因此并不实用。在本文中，我们证明预测校正方案可以提供完全隐式方案的一些优点。我们证明，每个时间步使用多个物理评估可以显着提高模型问题的准确性。我们还演示了进一步迭代的效果，原则上，它会收敛到完全隐式的方案。第二次迭代对整体性能影响很小，但对流量大幅减少。这表明当前的对流公式与此类积分方案不兼容。版权所有 © 2003 英国皇家气象学会
Methods of coupling the time integration of the resolved dynamics with the parametrized processes in atmospheric models are an active development area. Many centres have demonstrated strong sensitivity to variations in the methods of coupling in their models. The European Centre for Medium‐Range Weather Forecasts has recently introduced a revised method of coupling which gives significant forecast benefits. Theoretically, optimal methods are difficult to establish because of the mixture of timescales represented within the parametrizations. Implicit methods are well‐suited to achieving coupling between different processes, but are not practical because of the nonlinear switching present in most parametrization schemes. In this paper we show that a predictor–corrector scheme can give some of the advantages of a fully‐implicit scheme. We show that the use of more than one physics evaluation per time step significantly improves the accuracy in a model problem. We also demonstrate the effect of further iterations which, in principle, would converge towards a fully‐implicit scheme. A second iteration has only a small effect on overall performance, but gives a large reduction in the amount of convection. This indicates that the current formulation of convection is not compatible with this type of integration scheme. Copyright © 2003 Royal Meteorological Society