Horizontal and vertical transport of heat and moisture over complex terrain.

复杂地形上热量和湿气的水平和垂直输送。

基本信息

批准号：
05640473
负责人：
KIMURA Fujio
金额：
$ 1.34万
依托单位：
University of Tsukuba (1994)Tohoku University (1993)
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05640473/
关键词：
Atmospheric boundary layr Mixed layr Comprex terrain Anabatic wind Heat transport Moisture transport Linear theory Numerical model

项目摘要

Heat, moisture and momentum exchange process between the ground surface and atmosphere has not been clear enough. Study of the interaction between the atmosphere and the land surface is very important not only to clarify the local meteorology but also to study global climate change.The purpose of this study is to understand the mechanism of heat and moisture transport over simple valley and basin by field observation and numerical experiments.Ina valley is one of the most deep valley in Japan. Temperature and moisture profiles observed by radio sonde in this valley on clear and calm days are analized and it was found that the mixed layr in deep valley is consisted with two layrs, a turbulent mixed layr and a quasi mixed layr. The former is lower layr and is preserved by turbulence mainly generated by surface heat flux as well as the normal mixed layr over flat surface. The latter is upper layr and has slight stable stratification though temperature of this layr keeps increasing in daytime. The quasi mixed layr is formed by the circulation of anabatic wind over mountain slopes instead of turbulence.The quasi mixed layr was simulated by a numerical model and it was found that the mountain height must be taller than the mixed layr formed over flat topography for the formation of the qudsi mixed layr.A linear solution for anabatic and katabatic wind over complex topography is obtained. The linear model can clarify the relation between intensity of the wind and horizontal scale of topography. The results show that the katabatic wind will be strongest when the horizontal scale of the topography is about 100km.If the horizontal scale of the topography is much smaller than this, potential temperature tends to distribute to be horizontally uniform.

地面和大气之间的热量，水分和动量交换过程还不够清晰。研究大气与陆地表面之间的相互作用不仅非常重要，不仅要阐明当地的气象学，而且要研究全球气候变化。本研究的目的是了解通过现场观察和数值实验在简单山谷和盆地上传递热量和水分的机制。inina山谷是日本最深山谷之一。在晴朗而平静的日子里，无线电在这个山谷中观察到的温度和水分特征是对深山谷中的混合层组成的，该混合层与两个Layrs组成，一个湍流的混合Layr和Quasi混合Layr。前者是较低的Layr，并通过主要由表面热通量以及平坦表面上的正常混合Layr产生的湍流来保存。后者是上层的，尽管该Layr的温度在白天保持升高，但具有轻微的稳定分层。 The quasi mixed layr is formed by the circulation of anabatic wind over mountain slopes instead of turbulence.The quasi mixed layr was simulated by a numerical model and it was found that the mountain height must be taller than the mixed layr formed over flat topography for the formation of the qudsi mixed layr.A linear solution for anabatic and katabatic wind over complex topography is obtained.线性模型可以阐明风的强度与地形水平尺度之间的关系。结果表明，当地形的水平尺度约为100公里时，katabatic风将是最强的。如果地形的水平尺度远小于此，则潜在温度往往分布到水平均匀。