Resonant and nonresonant wave‐wave interactions in an isothermal atmosphere
Resonant and nonresonant wave‐wave interactions in an isothermal atmosphere
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DOI：
10.1029/jd093id04p03729
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发表时间：
1988-04
影响因子：
--
通讯作者：
B. Dong;K. Yeh
中科院分区：
文献类型：
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作者：
B. Dong;K. Yeh
我们考虑等温大气中的弱非线性三波相互作用。研究了动力-热力学大气运动(重力波、声波和涡旋运动)的三个线性分支之间的相互作用。除了共振情况外，还考虑了非共振相互作用。根据可能存在频率失配的线性化波幅方程的解析解，计算了各种情况下k-空间三维几何中的共振面、相互作用域和生长时间，并给出了一些数值结果。研究发现，非共振相互作用是非常重要的，特别是当重力波和两种涡旋运动模式作为一个非共振三重奏相互作用时。重力波向涡旋运动的能量转移可能会限制重力波振幅的增长，从而可能为重力波在中层大气中饱和提供一种合理的机制。
We consider the weakly nonlinear three-wave interactions in an isothermal atmosphere. The mutual interactions among the three linear branches of dynamical-thermodynamical atmospheric motions (gravity waves, acoustic waves, and vortical motions) are investigated. In addition to the resonant case, nonresonant interactions are also considered. On the basis of the analytical solution of the linearized wave-amplitude equation with possible existence of a frequency mismatch, the resonance surface, the interaction domain, and growth time in three-dimensional geometry in k-space in various cases have been calculated and some numerical results are given. It is found that the nonresonant interaction can be very important, especially when a gravity wave and two vortical modes of motions interact as a nonresonant trio. The energy transfer from the gravity wave to vortical motions might limit the growth of the gravity wave amplitude and hence might provide a reasonable mechanism for gravity waves to saturate in the middle atmosphere.