副高与阻高形成的Rossby孤立波理论Ⅱ:存在临界层
THE THEORY OF SOLITARY ROSSBY WAVES OF THE FORMATION OF SUBTROPICAL HIGH AND BLOCKING HIGH PART Ⅱ:WITH A CRITICAL LAYER
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摘要: 研究了存在临界层的非均匀纬向流中的Rpssby孤立波。在求出振幅函数满足的kdv方程或修正kdv方程(Mkdv)后,选择Chebyshev多项式作为展开基函数,用假谱方法,求解本征值和本征函数。对理想风场的计算表明,在临界层存在与否两种情况下,都能得到在东西风界面处的反气旋式副高型Rossby孤立波,同副高有一致的演变规律:当东风带相对强于西风时,向西移动;当西风相对强于东风时,则向东移动。在西风带,则得到阻高型Rossby孤立波,与阻高也有同样的演变规律。另外,我们还用连续谱方法计算了临界层附近的连续谱及离散谱,也得到与假谱方法较一致的结论。Abstract: The solitary Rossby waves with a critical layer in the nonuniformed zonal flows in the barotropic atmosphere are studied.After the KdV or the modified KdV equation which were satisfied by the streamfunctions had been gotten,the chebyshev polynomials and the pseudo-spectral method were applied in solving the eigenvalue problems.The computation of ideal wind field showed that whether there was a critical layer or not,the Subtropical high solitary Rossby waves which had the same evolution patterns as the actual subtropical high's can be obtained.And the blocking high solitary Rossby waves which also resemble actual blocking high's could be gotten too.Through a second method by calculating continuous and discrete spectrum on or near the critical layer,results similar to those chebyshev pseudospectral method are obtained.which conform our theory.