Theoretical studies on the interaction between the general circulation and small-scale phenomena.

在所谓的参数化中，我们评估小尺度现象对所考虑的大尺度运动的影响，通常使用后者变量。然而，如果我们正确地处理相互作用，方程将成为非线性的，包括反馈效应的大规模运动的修改较小的，并会导致我们有些困难的情况下，因为它通常是不可能忽略的反馈，除非它的时间尺度足够长的情况下。方程的非线性会引起解的分叉。参数化的想法不一定涉及这种考虑。然后，作为建立合理的参数化思想的第一步，我们将平流层垂直一维模式作为一个非线性系统，其中平均纬向气流和行星波相互影响，并考察了解的分叉和对外力的响应。我们成功地合理地或可靠地回答了行星波为什么能在冬末增强，这些现象可以解释为气候稳定性与气候变化的转换，本文讨论了平流层中重力波与平均环流相互作用对太阳差异加热季节性变化的响应，并预测了近年来在重力波参数化中所研究的重力波与平均环流相互作用问题也可能出现类似的情况。

In the so-called parameterization, we evaluate the effects of smaller scale phenomena on the large-scale motion considered, usually with use of the latter variables. However, if we treat the interaction correctly, the equations will become non-linear, including the feed-back effects of the large-scale motion modified by the smaller ones, and will lead us to somewhat difficult situation, because it is generally impossible to omit the feed-back, except the case where its time-scale is sufficiently longer. The non-linearity of equation may cause the bifurcation of solutions. The idea of parameterization does not necessarily involve such a consideration. Then, in this wotk, as the first step toward founding a reasonable idea of parameterization, we have a vertical one dimensional model of the stratosphere as a non-linear system in which the mean zonal flow and planetary waves are mutually affecting, and examined the bifurcation of the solutions and also the response to external forcing.As the result, we have succeeded to answer reasonably or soundly the problems such as why the planetary waves can amplify in late winter, why the sudden warmings prefer late winter or early spring to other seasons and so on. These phenomena can be interpreted as the transitions among stable equilibrium states, occuring in the stratosphere responding to the seasonal change in solar differential heating.We anticipate that similar situations may appear in the prblem of interaction between gravity wave and the mean circulation, which is being intensively studied in recent years with respect to the gravity wave parameterization.