Development and propagation of equatorial waves |
| |
| Authors: | Xiao fan Li Han-Ru Cho |
| |
| Institution: | Department of Physics, University of Toronto, Toronto, Ontario, Canada, M5S1A7,Department of Physics, University of Toronto, Toronto, Ontario, Canada, M5S1A7 |
| |
| Abstract: | Development and propagation of equatorial waves are investigated with the model which includes convection-wave convergence
feedback and convection-frictional convergence feedback. Two experiments with an initial Kelvin wave (Exp. K) and with an
initial Rossby wave (Exp. R) are carried out. The equatorial waves in Exp. R grow much faster than those in Exp. K. The equatorial
waves in both experiments follow zonal (eastward / westward) and meridional (poleward) propagation.
The equatorial waves can be partitioned into two meridional modes using Parabolic Cylinder Function. An equator mode denotes
a wave component with a positive precipitation center at the equator and an off-equator mode represents a wave component with
positive precipitation centers off the equator. The equator mode dominates in Exp. K whereeas the off-equator mode dominates
in Exp. R. The rapid wave growth in Exp. R is interpreted by analyzing the eddy available potential energy (EAPE) generation.
Stronger off-equator mode in Exp. R obtains more EAPE through convection-frictional convergence feedback which results in
more rapid wave growth.
The relative vorticity tendency is determined by interactions between Earth’s vorticity and lower-troposphere convergence
(divergence effect) and between the meridional gradient and lower-troposphere circulation (beta effect). The eastward and
poleward propagation of equatorial waves is a result of the divergence effect, and the westward movement is caused by the
beta effect. |
| |
| Keywords: | Equatorial waves Development Propagation Eddy available potential energy Vorticity tendency |
| 本文献已被 SpringerLink 等数据库收录！ |
| 点击此处可从《大气科学进展》浏览原始摘要信息 |
| 点击此处可从《大气科学进展》下载免费的PDF全文 |
|
