Linear and Nonlinear Signatures in the Planetary Wave Dynamics of an AGCM: Probability Density Functions
Linear and Nonlinear Signatures in the Planetary Wave Dynamics of an AGCM: Probability Density Functions
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DOI：
10.1175/jas3822.1
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发表时间：
2007
影响因子：
3.1
通讯作者：
J. Berner;G. Branstator
中科院分区：
文献类型：
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作者：
J. Berner;G. Branstator
摘要为了识别和量化线性和非线性行星波行为及其对大气状态分布的影响，研究了四维相空间中大气环流模式（GCM）的长积分特征。相空间由500百帕位势高度的四个经验正交函数定义。首先，它是建立在相空间行为在这个GCM的早期研究中所报道的类似的非线性趋势有可能导致非高斯特征的概率密度函数（PDF）的行星波。然后，使用客观的措施，它表明，该模型的状态分布具有鲜明的非高斯特性。这些功能的特点是在各种子空间的维度高达4。一个主要特征是存在三个辐射脊的增强概率从模式发出，这是远离气候平均值。
Abstract To identify and quantify indications of linear and nonlinear planetary wave behavior and their impact on the distribution of atmospheric states, characteristics of a very long integration of an atmospheric general circulation model (GCM) in a four-dimensional phase space are examined. The phase space is defined by the leading four empirical orthogonal functions of 500-hPa geopotential heights. First it is established that nonlinear tendencies similar to those reported in an earlier study of the phase space behavior in this GCM have the potential to lead to non-Gaussian features in the probability density function (PDF) of planetary waves. Then using objective measures it is demonstrated that the model’s distribution of states has distinctive non-Gaussian features. These features are characterized in various subspaces of dimension as high as four. A key feature is the presence of three radial ridges of enhanced probability emanating from the mode, which is shifted away from the climatological mean...