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

大环流与小尺度现象相互作用的理论研究。

基本信息

批准号：
60540261
负责人：
URYU Michiya
金额：
$ 0.51万
依托单位：
Kyushu University
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1985
资助国家：
日本
起止时间：
1985 至 1986
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-60540261/
关键词：
prameterization non-linear bifurcation the stratosphere as a non-linear system ヒステリシス

项目摘要

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.

在所谓的参数化中，我们通常使用后者的变量来评估较小尺度现象对所考虑的大尺度运动的影响。然而，如果我们正确地处理相互作用，方程将变得非线性，包括由较小的运动修正的大尺度运动的反馈效应，并且将导致我们遇到一些困难的情况，因为通常不可能忽略反馈，除非其时间尺度足够长。方程的非线性可能导致解的分岔。参数化的思想并不一定涉及这样的考虑。然后，在本工作中，作为建立合理参数化思想的第一步，我们建立了平流层的垂直一维模型，作为非线性系统，其中平均纬向流和行星波相互影响，并研究了由此，我们成功地合理、合理地回答了行星波为何在冬末会放大、为什么突然变暖更倾向于冬末早春等问题。其他季节等等。这些现象可以解释为平流层中发生的稳定平衡状态之间的转变，以响应太阳差异加热的季节变化。我们预计，类似的情况也可能出现在重力波与平均环流之间的相互作用问题中，该问题正在研究中。近年来，人们对重力波参数化进行了深入研究。