地球旋转向量水平分量对赤道β平面上波动的影响

文中利用合理的赤道 β平面近似方程组研究 β效应和地球旋转向量水平分量 (即Coriolis力分量 f*=2 Ω cosφ)共同作用下低纬度大气波动的特征。定性结果分析表明 ,若扰动与纬度有关 (混合 Rossby-重力波和 Rossby波 ) ,f*虽然不影响波动传播的频率特征 ,但修改其决定波动经向结构的振幅。如果扰动与纬度无关 (Kelvin波 ) ,则 f*的影响消失 ,这与 f*- f平面上波动的情况显然不同。

INFLUENCE OF THE HORIZONTAL COMPONENT OF THE EARTH

A horizontal component of the earth's rotation (f*=2Ωcos φ) is included in a set of linearized β-plane equations, which have a constant horizontal component of the Coriolis parameter, while the vertical component varies with latitude. This feature of the equations enables the vorticity and angular momentum principles to hold in their usual form, to study the influence of the f*-effect on waves on the equatorial-plane. The results show that the f*-effect can be important if the perturbations are the function of latitude. Although f* has no effects on the frequencies of the mixed Rossby-gravity and Rossby waves, it modifies their amplitude. We also find that when the perturbations are independent of latitude (e.g. Kelvin waves), the f*-effect disappears.