General aspects of a T213L256 middle atmosphere general circulation model
General aspects of a T213L256 middle atmosphere general circulation model
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DOI：
10.1029/2008jd010026
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发表时间：
2008-06
影响因子：
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通讯作者：
S. Watanabe;Y. Kawatani;Y. Tomikawa;K. Miyazaki;M. Takahashi;Kaoru Sato
中科院分区：
文献类型：
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作者：
S. Watanabe;Y. Kawatani;Y. Tomikawa;K. Miyazaki;M. Takahashi;Kaoru Sato
本文介绍了一种用于研究小尺度大气过程的高分辨率大气环流模式，并讨论了该模式的一般特征。GCM的光谱水平分辨率为T213，垂直高度为256，垂直间距均匀为300 m，从地面延伸至85 km。重力波（GWs）是由模式中的对流、地形、不稳定和调整过程自发产生的，GCM再现了温带平流层和中间层的真实环流。类似平流层顶半年振荡和赤道平流层下层准两年振荡（QBO）的振荡也在GCM中自发产生，尽管类似QBO的振荡周期较短（15个月）。通过对行星波、大尺度吉瓦和小尺度吉瓦分别计算Eliassen-Palm诊断值，评估了行星波、大尺度吉瓦和小尺度吉瓦在维持中层大气纬向风射流经向结构中的相对作用。发现小尺度GWs引起冬季极夜急流和夏季中间层偏东急流的减速，而温带行星波主要引起约60 km高度以下极夜急流的减速。小尺度GWs的经向分布和传播会影响中层射流上部的形状。本文以T213L256型GCM再现的真实GWs为例，讨论了南安第斯山脉地形GWs的相位结构和对流层急流发射的GWs。
[1] A high-resolution middle atmosphere general circulation model (GCM) developed for studying small-scale atmospheric processes is presented, and the general features of the model are discussed. The GCM has T213 spectral horizontal resolution and 256 vertical levels extending from the surface to a height of 85 km with a uniform vertical spacing of 300 m. Gravity waves (GWs) are spontaneously generated by convection, topography, instability, and adjustment processes in the model, and the GCM reproduces realistic general circulation in the extratropical stratosphere and mesosphere. The oscillations similar to the stratopause semiannual oscillation and the quasi-biennial oscillation (QBO) in the equatorial lower stratosphere are also spontaneously generated in the GCM, although the period of the QBO-like oscillation is short (15 months). The relative roles of planetary waves, large-scale GWs, and small-scale GWs in maintenance of the meridional structures of the zonal wind jets in the middle atmosphere are evaluated by calculating Eliassen-Palm diagnostics separately for each of these three groups of waves. Small-scale GWs are found to cause deceleration of the wintertime polar night jet and the summertime easterly jet in the mesosphere, while extratropical planetary waves primarily cause deceleration of the polar night jet below a height of approximately 60 km. The meridional distribution and propagation of small-scale GWs are shown to affect the shape of the upper part of mesospheric jets. The phase structures of orographic GWs over the South Andes and GWs emitted from the tropospheric jet stream are discussed as examples of realistic GWs reproduced by the T213L256 GCM.