Contrasting meridional structures of stratospheric and tropospheric planetary wave variability in the Northern Hemisphere
Contrasting meridional structures of stratospheric and tropospheric planetary wave variability in the Northern Hemisphere
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北半球平流层和对流层行星波变化的对比经向结构
DOI：
10.3402/tellusa.v66.25303
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发表时间：
2014-11
影响因子：
2
通讯作者：
Xie, Fei
中科院分区：
文献类型：
--
作者：
Sun, Cheng;Li, Jianping;Jin, Fei-Fei;Xie, Fei
利用再分析资料研究了北方半球热带外平流层和对流层行星波变率（PWV）的纬向结构。通过对位势高度数据进行球面双傅里叶级数展开，可以在二维波数（纬向和纬向波数）空间中考察各垂直层上PWV的水平结构。比较近30年来各波分量的振幅，结果表明北半球对流层PWV的结构与平流层PWV的结构有很大的不同。对流层中的PWV表现为多纬向波型结构，以纬向偶极子最为明显;而平流层中的PWV则主要表现为大尺度纬向波型，以纬向波1和2为主，纬向波动较小。NHPWV的优势型也显示出平流层和对流层纬向结构的对比特征。在二维波数空间中，平流层中PWV的前两个经验正交函数主要表现为纬向波1型，而对流层中PWV的前两个经验正交函数则明显表现为纬向波1型，并以偶极子为主。根据纬向平均基态导出了折射率，定性地解释了观测结果。结果表明，北半球对流层的基本状态比平流层更有利于定常波的纬向传播。在线性斜压模式中，利用观测到的纬向平均基本状态，可以很好地捕捉到平流层和对流层行星波纬向结构的差异。此外，理论和模拟分析表明，纬向波模式是首选在北半球平流层的事实可能部分归因于平流层纬向平均基本状态的垂直曲率。
The meridional structures of stratospheric and tropospheric planetary wave variability (PWV) over the Northern Hemisphere (NH) extratropics were investigated and compared using reanalysis data. By performing the spherical double Fourier series expansion of geopotential height data, the horizontal structures of PWV at each vertical level could be examined in the two-dimensional (2D) wavenumber (zonal and meridional wavenumbers) space. Comparing the amplitudes of wave components during the last three decades, the results suggested that the structures of PWV in the NH troposphere significantly differ from the stratospheric counterparts. The PWV in the troposphere shows multiple meridional wave-like structures, most pronounced for the meridional dipole; while in contrast, PWV in the stratosphere mainly shows large-scale zonal wave patterns, dominated by zonal waves 1 and 2, and have little wave-like fluctuation in the latitudinal direction. The dominant patterns of the NH PWV also show contrasting features of meridional structure between the stratosphere and the troposphere. As represented in the 2D wavenumber space, the leading two empirical orthogonal functions of PWV in the stratosphere largely exhibit the zonal wave 1 pattern, while those in the troposphere clearly show meridional wave-like structures and are dominated by the dipole. The refractive index was derived based on the zonal mean basic state to qualitatively interpret the observational findings. The results suggested that the basic state in the NH troposphere is much more favourable for latitudinally propagating stationary waves than the stratosphere. The difference in meridional structure between stratospheric and tropospheric planetary waves can be well captured in a linear baroclinic model with the observed zonal mean basic state. Furthermore, both theoretical and modelling analyses demonstrated that the fact that zonal wave patterns are preferred in the NH stratosphere may be partly attributable to the vertical curvature of the stratospheric zonal mean basic state.
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影响因子：
6.3
作者：
F. Xie;J. Li;W. Tian;Juan Feng;Y. Huo
通讯作者：
F. Xie;J. Li;W. Tian;Juan Feng;Y. Huo
影响因子：
4.4
作者：
Garfinkel, C. I.;Hartmann, D. L.
通讯作者：
Hartmann, D. L.
影响因子：
3.1
作者：
T. Tsuda;T. Inoue;S. Kato;S. Fukao;D. Fritts;T. Vanzandt
通讯作者：
T. Tsuda;T. Inoue;S. Kato;S. Fukao;D. Fritts;T. Vanzandt
影响因子：
3.1
作者：
Hock Lim;Chih-Pei Chang
通讯作者：
Hock Lim;Chih-Pei Chang
影响因子：
3.1
作者：
Wei‐Chyung Wang;J. Pinto;Y. Yung
通讯作者：
Wei‐Chyung Wang;J. Pinto;Y. Yung