Rp. Matano, NUMERICAL EXPERIMENTS ON THE EFFECTS OF A MERIDIONAL RIDGE ON THE TRANSMISSION OF ENERGY BY BAROTROPIC ROSSBY WAVES, J GEO RES-O, 100(C9), 1995, pp. 18271-18280
Analytical and numerical models are used to study the effects of a mer
idional ridge on the propagation of barotropic Rossby waves produced b
y distant wind stress forcing. The analytical model illustrates the qu
alitative aspects of the problem by solving a simplified form of the p
otential vorticity equation. The analytical results are complemented b
y numerical experiments using a shallow-water model. In these experime
nts, waves are excited near the eastern boundary of the model. The eff
ect that the presence of a meridional ridge has on the propagation of
these waves is evaluated using spectral analysis. The numerical experi
ments show that the ridge acts as a low-pass filter for westward propa
gating waves. In a 4000-m deep ocean a ridge 500 km wide and 500 m hig
h has little effect in preventing energy transmission by barotropic wa
ves. The topographic effect increases sharply with the ridge's height
so that a 2000-m ridge almost isolates two neighboring subbasins. The
numerical results indicate that for the range of geophysically relevan
t cases the ridge's width plays only a minor role.