旋转大气中地形对涡旋自组织影响的初步研究

Preliminary Study on the Influence of Topography on Vortex Self-Organization in the Rotational Atmosphere

用一个带有地形项的β平面准地转正压涡度方程,进行2组积分时间长度为48h的试验,分析旋转大气中地形对多涡自组织的影响。地球旋转作用的引入主要会引起以下的差别:无旋转大气中,多涡自组织的特征是准终态涡将初始多涡全部吸收或全部组织起来;旋转大气中,多涡自组织的特征是准终态涡将初始多涡部分吸收或部分组织起来,差别较明显。中尺度地形对准终态涡位置的影响不同。无旋转大气中,中尺度地形对准终态涡位置的影响较小,有无地形的两个准终态涡中心之间的距离约100km;旋转大气中,中尺度地形对准终态涡位置的影响较大,有无地形的两个准终态涡中心之间的距离约200km,两者相差一倍左右。

In order to investigate the effect of the topography on the vortex self-organization in the rotational atmosphere, two numerical experiments, with 48 hours integral time are performed by using a β- plane quasi-geostrophic barotropic vorticity equation model with a topographic term. The main distinct differences between the rotational and non rotational atmosphere resulting from introducing the β term are as follows：Firstly, in the non rotational atmosphere, the characteristics of the multi-vortices self-or- ganization are that the quasi-final vortex absorb or organize all of the initial multi-vortices;but those in the rotational atmosphere are absorbing or organizing the initial multi-vortices partly. Secondly, the influences of mesoscale topography on the quasi-final structure position are smaller in the non rotational atmosphere than that in the rotational atmosphere ;the distance between the two quasi-final vortex cen- ters in the rotational atmosphere is as twice as that in the non rotational one, the former is about 200 km but the latter about 100 km no matter introducing the topographic term.