近日，中国科学院大气物理研究所王林团队研究了不同规定大气分层中静止行星波的垂直结构和能量传递。这一研究成果于2025年4月9日发表在《大气科学进展》杂志上。

研究组调查了大气分层（即静态稳定性N^2）与静止行星波垂直能量转移之间的关系，并进一步说明了潜在的物理机制。具体来说，对于平流层N^2恒定的简化情况，行星波的折射率平方具有随N^2先增加后减小的理论趋势，而群速度减弱。

从力学上讲，这种行为可以理解为在强N^2条件下，行星波经向热输运引起的垂直等熵表面位移的强化抑制。观测分析证实了这一发现，表明N^2波的垂直传播速度降低。使用适用于平流层的具有恒定背景西风和规定N^2的线性准地转中纬度β平面模型来获得解析解。

在这个模型中，行星波是由底部边界的稳定能量流入引发的。分析表明，在强N^2条件下，由于垂直能量传递的减缓，行星波幅可以通过有效能量收敛得到充分放大，导致该模型中的流函数响应包含更多能量。对于垂直拟线性N^2，结果与常数情况相似，除了波幅和振荡频率显示出一些垂直变化。

附：英文原文

Title: Vertical Structure and Energy Transfer of Stationary Planetary Waves in Different Prescribed Atmospheric Stratification

Author: Wenqi Zhang, Lin Wang

Issue&Volume: 2025-04-09

Abstract: This study investigated the relationship between atmospheric stratification (i.e., static stability N^2) and vertical energy transfer of stationary planetary waves, and further illustrated the underlying physical mechanism. Specifically, for the simplified case of constant stratospheric N^2, the refractive index squared of planetary waves has a theoretical tendency to increase first and then decrease with N^2, whereas the group velocity weakens. Mechanistically, this behavior can be understood as an intensified suppression of vertical isentropic surface displacement caused by meridional heat transport of planetary waves under strong N^2 conditions. Observational analysis corroborates this finding, demonstrating reduced vertical propagation velocity of waves with N^2. A linear quasi-geostrophic mid-latitude beta-plane model with constant background westerly wind and prescribed N^2 applicable to the stratosphere is used to obtain analytic solutions. In this model, the planetary waves are initiated by steady energy influx from the bottom boundary. The analysis indicates that under strong N^2 condition, planetary wave amplitude can be sufficiently amplified by the effective energy convergence due to the slowing vertical energy transfer, resulting in the stream function response in this model containing more energy. For the vertically quasi-linear N^2, the results bear a resemblance to the constant case, except that the wave amplitude and oscillating frequency show some vertical variations.

DOI: 10.1007/s00376-025-4511-9

Source: http://www.iapjournals.ac.cn/aas/article/doi/10.1007/s00376-025-4511-9