大地形和外源激发的定常和非定常的行星波动
THE STEADY AND UNSTEADY PLANETARY WAVES EXCITED BY TOPOGRAPHY AND EXTERNAL SOURCE
-
摘要: 利用包括地形和外源的涡度方程,讨论了大地形和外源产生的定常和非定常行星波动,结果显示,在西风带,地形和外源都能激发出定常和非定常行星尺度波型扰动,在东风带只能产生地形和外源附近的衰减型扰动,对非定常流场,西风带中只能在地形或外源的下游激发行星波动,在地形和外源的上游没有扰动流场产生,当时间t≥x/u时,在下游可得到稳定的行星波动,小于这一时间,行星波动处于建立过程中;在东风带,地形和外源激发的衰减型扰动要稳定维持需无限长时间。地形和外源激发的定常和非定常行星波动有的位相差,地形上空产生的定常和非定常扰动是槽或是脊,与扰动波长有关,地形产生与地形同位相或反位相的波动,外源激发的定常和非定常扰动的槽脊线位置与外源有的位相差,外源激发的槽或脊都比地形产生的向下游移动。Abstract: The steady and unsteady Rossby waves are studied by using a vorticity equation including topography and external source. The results show that in the westerlies topography and external source can excite planetary scale steady and unsteady waveform disturbances, but in the easterlies they can only excite disturbances which are bound to be decaying soon enough. The solutions also show that there is a phase difference of π/2 between the waves excited by topography and those by external source.
-
Key words:
- Topography /
- External source /
- Stationary /
- Non－stationary /
- Planetary waves
-
点击查看大图
计量
- 文章访问数: 726
- HTML全文浏览量: 0
- PDF下载量: 548
- 被引次数: 0
下载:
粤公网安备 4401069904700003号