摘要
对非保守系统中的对称不稳定问题进行了研究。这里是该文的第二部分,主要讨论弱加热的强迫作用。研究结果表明,采用WaveCISK方法考虑弱加热的影响时,发现中高层加热只对一个较为狭窄的短波段扰动具有增长作用,而对其它波长较长的扰动则反而起到衰减作用。中低层加热能够提高波长较长的扰动之增长率,但会削减波长较短扰动的增长率。此外,由于潜热加热作用而新产生的大部分模态都偏向南(即暖区)传播,随着最高加热层次的降低,这种偏向更为明显,但也有向冷区传播的情况。
The present paper has comprehensively dealt with the problems of symmetric instability in nonconservative systems. The forcing effect of weak heating is studied in this part. From examination of the effect of weak heating by using waveCISK method, it is found that the upperlevel heating can only develop the disturbances which are in a narrow spectrum of short waves, but decay other disturbances whose wavelengthes are longer. The lowlevel heating can increase the growth rate of the disturbances in larger wavelengthes, but decrease the growth rate of the disturbances in short wavelengthes. In addition, the most of the modes newly induced by latent heating propagate toward the south (i. e. warm sector). The southward phase velocity is bigger with lowering of the level of the heating peak. Some other disturbances may propagate toward cold sector.
出处
《大气科学》
CSCD
北大核心
1998年第3期274-282,共9页
Chinese Journal of Atmospheric Sciences
基金
国家自然科学基金
关键词
非保守系统
弱加热
对称不稳定
中尺度
大气
nonconservative systems weak heating conditional symmetric instability