The mechanism of the generation of reaction‐diffusion waves in the mesopause region (80–90 km) has been studied analytically. These waves are the propagating phase fronts arising in the oscillations of O, O₃, H, OH, and HO₂ concentrations. They appear in the presence of horizontal eddy diffusion in zonal direction when mesospheric photochemistry responds subharmonically (with a period of 2 days) to diurnal variations of solar radiation. The photochemical system in the mesopause region is a nonlinear oscillator which can be roughly described by a system of two differential nonautonomous equations with power law nonlinearity which was derived in our earlier papers. To model the wave propagation, we have considered a continuous chain of oscillators with diffusion coupling and with the phase of external periodic forcing depending linearly on spatial coordinates. It was found that the reaction‐diffusion waves are caused by specific “wind” type transport appearing in the equations for the amplitudes of 2‐day photochemical oscillations of O and H concentrations due to the zonal inhomogeneity of the external forcing. The obtained expression for the wave propagation velocity fully confirmed the earlier numerical results that the magnitude of the velocity is proportional to the diffusion coefficient and the gradient of the external forcing phase. The wave propagation direction is determined by the definite phase relations specified by internal parameters of the system only.

中文翻译：

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中更年期光化学中反应扩散波的分析研究

已经对中绝经区（80-90 km）中反应扩散波的产生机理进行了分析研究。这些波是在O，O ₃，H，OH和HO ₂的振荡中产生的传播相锋。浓度。当中层光化学对太阳辐射的昼夜变化进行亚谐响应（周期为2天）时，它们会出现在纬向水平涡流扩散的情况。中生绝经区域的光化学系统是一个非线性振荡器，可以用两个具有幂律非线性的微分非自治方程组粗略地描述，该方程是在我们较早的论文中得出的。为了模拟波传播，我们考虑了具有扩散耦合和外部周期强迫相位线性依赖于空间坐标的振荡器的连续链。已经发现，反应扩散波是由方程式中出现的特定“风”型传输引起的，这些方程式是由于外部强迫的区域不均匀性引起的O和H浓度2天光化学振荡幅度的关系。所获得的波传播速度表达式完全证实了较早的数值结果，即速度的大小与扩散系数和外强迫相的梯度成比例。波的传播方向仅由系统内部参数指定的确定相位关系确定。所获得的波传播速度表达式完全证实了较早的数值结果，即速度的大小与扩散系数和外强迫相的梯度成比例。波的传播方向仅由系统内部参数指定的确定相位关系确定。所获得的波传播速度表达式完全证实了较早的数值结果，即速度的大小与扩散系数和外强迫相的梯度成比例。波的传播方向仅由系统内部参数指定的确定相位关系确定。