【摘要】 对热带干大气运动的长波、纬向超长波（纬向扰动尺度L₁～10⁴公里,经向扰动尺度L₂～10³公里）和经向超长波（L₁～10³公里,L₂～10⁴公里）进行了尺度分析,得到了适合这些运动的近似方程。对于纬向超长波,与长波的情况一样为正压无辐散运动;但在经向超长波时,则涡度方程中存在辐散项,这一结果与Matsuno得到的在热带存在Rossby波和惯性-重力波混合的情况是一致的。同时,在存在基本气流切变的情况下,对线性化扰动方程进行了频率分析,结果指出,当n≥1时,Rossby波和惯性-重力波是可分的;当n=0,而纬向尺度L₁～1000公里时,存在混合Rossby-重力波,这就证实了上述尺度分析的结果是正确的。于是,把尺度分析的结果与热带波动运动中Rossby波和惯性-重力波是可分的或混合的特性统一了起来。更多还原

【Abstract】 The scale analysis for the long wave and zonal ultra-long wave (the zonal scale of the perturbance L1-104 km, the meridional scale L2-103 km) and meridional ultra-long wave (L1-103 km, L1-104 km) is carried out, and a set of approximate equations suitable to the motion of these waves in a dry tropical atmosphere is obtained. For the zonal ultra-long wave, the motion of which is the same with that of long wave, the vor-ticity equation is barotropie nondivergence; while for meridional ultra-long wave the vorticity equation has a divergence term. This result agrees with that of Matsuno who obtained the mixed Rossby-gravity wave in the dry tropical atmosphere. Under the condition of shear of basic current, the frequency analysis for the linearized disturbance equations is carried out. It is found that Rossby wave and gravity wave may be separated for n≥1, but for n=0, L1-1000 km, the mixed Rossby-gravity wave will appear. Hence it is confirmed that above results of scale analysis are correct. The consistency between frequency analysis and scale analysis is established.更多还原