Abstract: A baroclinic 2-layer model, including diabatic facter, was established to analyse the effects of diabatic factor on ultra-long waves in the tropical atmosphere. The results showed that each of diabatic facters could change the characteristics of adiabatic ultra-long waves, this could be seen in two ways: 1. the stability. 2. the propagating characteristics (including propagating direction and phase velocity). Thus, a conclusion could be obtained that low-frequency oscillation, such as intra-seasonal oscillation et al., is a kind of diabatic waves generated by diabatic factors in common. This kind of diabatic waves is an important factor to generate the long-and medium range variations and short-range climatic anomalies.

Key words: diabatic waves, low-frequency oscillation

摘要： 应用含有非绝热因子的斜压两层模式方程组，讨论了非绝热因子对低纬超长波动的作用。分析表明各种非绝热因子都改变了原绝热超长波的性质，主要体现在2个方面：波的稳定性和波动的传播特性(包括传播方向和传播速度)。由此，可以认为所谓的季节内振荡等低频振荡实际上是各种非绝热因子共同作用引起的一类非绝热波，这类非绝热波是引起中长期天气变化和短期气候异常的重要因素。

关键词: 非绝热波, 低频振荡