Energy spectrum proportional to the squared phase speed of Rossby modes in the general circulation of the atmosphere
Energy spectrum proportional to the squared phase speed of Rossby modes in the general circulation of the atmosphere
复制标题
能谱与大气环流中罗斯贝模式的平方相速度成正比
DOI：
10.1029/2004gl019826
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发表时间：
2004
影响因子：
5.2
通讯作者：
Takahiro Kanda
中科院分区：
文献类型：
--
作者：
Hiroshi L. Tanaka;Yasushi Watarai;Takahiro Kanda
本文在三维简正波分解的框架下，研究了大尺度大气运动的能量谱。扰动的水平尺度由Rossby模c的相速度来测量。根据对大气正压分量的分析结果，我们得到了由球面莱茵河速度分隔的湍流和波型的具有明显斜率的特征能谱。为了解释能谱与c2成正比的观测结果，我们提出了一个基于Rossby波破裂准则的假设，使得位涡的局部经向梯度∂q/∂y<；0在区域的某处变为负值。用一个描述单位面积大气总质量的常数m，我们证明了大气环流E的正压能谱可表示为E=mc2。
In this study, energy spectrum of the large‐scale atmospheric motions is examined in the framework of the 3D normal mode decomposition. The horizontal scale of disturbance is measured by the phase speed of a Rossby mode c. According to the analysis result for the barotropic component of the atmosphere, we obtain a characteristic energy spectrum with distinct slopes for the turbulence and wave regimes separated by the spherical Rhines speed. In order to explain the observational finding that the energy spectrum is proportional to c2, we put forward a hypothesis based on the criterion of Rossby wave breaking such that the local meridional gradient of potential vorticity becomes negative, ∂q/∂y < 0, somewhere in the domain. With a constant m describing a total mass of the atmosphere for unit area, we have shown that the barotropic energy spectrum of the general circulation E can be represented as E = mc2.