On the effect of the land-ocean contrast to the monsoon circulation

陆海对比对季风环流的影响

基本信息

批准号：
02452058
负责人：
SUMI Akimasa
金额：
$ 3.39万
依托单位：
Center for Climate System Research, University of Tokyo
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (B)
财政年份：
1990
资助国家：
日本
起止时间：
1990 至 1991
项目状态：
已结题

项目摘要

Characteristics of the coupled land-ocean atmosphere system have been investigated by using numerical models. Numerical experiments have been designed and conducted in two different experimental set-up ; (1) an atmospheric model is used with assumed Sea Surface Temperature (SST), and (2) an ocean-atmosphere coupled model is used.Two extreme cases were investigated ; (1) the land surface is desert-like, where few evaporation is supplied, and (2) the land surface is swamp, where infinite moisture supply from land surface can be expected. In both cases, rectangular ocean, which extends from 90ﾟE to 270ﾟE between 60ﾟN and 60ﾟS,is assumed.Following conclusions were obtained ;(1) When the land surface is dry, thermal contrast between land and sea is strong (land surface temperature is higher than SST), and the heat low are generated over the land. Convection center is located to the east of the ocean, and the monsoon westerly is also located in the eastern part of the ocean. This feature is also confirmed in the couled model run, where SST tends to be zonally uniform.(2) When the land surface is wet, the thermal contrast between land and ocean is reverse (Tg SST) to the previous case. In this case, convection center and the monsoon westerly is located to the western part of the ocean. This feature is also confirmed in the coupled-model run, where the SST in the eastern part of the ocean tends to decrease due to the upwelling caused by a strong easterly.In summary, it is suggested that there exists characteristic flow regimes corresponding to the land-ocean heat contrast.It is also shown where the seasonal forcing is stron, there is no interaseasonal variation.

使用数值模型研究了耦合陆地气氛系统的特征。数值实验是在两个不同的实验设置中设计和进行的。（1）与假定的海面温度（SST）一起使用大气模型，（2）使用了海洋 - 原子耦合模型。研究了两个极端病例；（1）土地表面像沙漠一样，很少提供蒸发，（2）土地表面是沼泽，可以预期无限的水分供应。在这两种情况下，都假定了从90°E延伸到60 n和60 ﾟS之间的270埃的矩形海洋。得出的结论得出了；（1）当土地表面干燥时，土地表面干燥，陆地和海洋之间的热对比度很强（土地表面温度较高），而陆地温度高于SST，并且在土地上产生了低生成的土地。对流中心位于海洋的东部，西部季风也位于海洋东部。在couled模型运行中也证实了此功能，在该模型运行中，SST往往是区域均匀的。（2）当陆地表面湿润时，土地和海洋之间的热对比是反向（TG SST）到上一个情况下的。在这种情况下，会议中心和季风西部位于海洋的西部。该功能在耦合模型运行中也得到了证实，由于强烈的东方造成的升高，海洋东部的SST往往会减少。总而言之，建议存在与陆地热相对相对应的特征流动方案。它也表明了季节性强迫的地方，而不是在季节性强迫上，没有层次的差异。