The Role of Equatorial Waves in the Semiannual Oscillation of The Middle Atmosphere
The Role of Equatorial Waves in the Semiannual Oscillation of The Middle Atmosphere
复制标题
赤道波在中层大气半年振荡中的作用
DOI：
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发表时间：
2013
期刊：
影响因子：
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通讯作者：
R. Garcia
中科院分区：
文献类型：
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作者：
R. Garcia
本文回顾了中层大气半年振荡(SAO)的观测特征，并用数值模拟重现了大部分观测行为。认为深对流释放的潜热激发了赤道开尔文波和惯性重力波，它们在驱动SAO的过程中起着主要作用。这些波的尺度从行星波(k=1-3)到中间波(k≃4-25)，周期不到5天。在本文的计算中，行星尺度的Kelvin波提供了平流层SAO西风相的一半以上的驱动，其余的由中尺度波提供；在中间层，西风相由行星Kelvin波和中尺度Kelvin波共同驱动，而日周期的惯性重力波对东风相的强迫作用最大。强迫中层东相的惯性重力波尤其受到准两年振荡(QBO)东相耗散的影响；这可能解释了卫星观测中所看到的QBO对中层SAO的明显调制。
A review of the observed features of the semiannual oscillation (SAO) of the middle atmosphere is presented, together with numerical simulations that reproduce much of the observed behavior. It is argued that latent heat release by deep convection excites equatorial Kelvin and inertia-gravity waves that play a major role in driving the SAO. The waves in question have scales ranging from planetary (k = 1 - 3) to intermediate (k ≃ 4 - 25), and periods less than 5 days. In the calculations presented here, planetary-scale Kelvin waves provide over half of the driving for the westerly phase of the stratospheric SAO, while the remainder is supplied by intermediate scale waves; in the mesosphere, the westerly phase is driven by a combination of planetary and intermediate-scale Kelvin waves, while inertia-gravity waves of diurnal period contribute most of the forcing for the easterly phase. The inertia-gravity waves responsible for forcing the mesospheric easterly phase are particularly affected by dissipation during the easterly phase of the quasibiennial oscillation (QBO); this may account for the apparent modulation of the mesospheric SAO by the QBO seen in satellite observations.