ESS228
Prof. Jin-Yi Yu
Equatorial
Waveguide
Linearized shallow-water
equations
Assume wave-form solutions
•Wave-like
solutions can result from this equation if this
coefficient has a positive value.
•When
y increases (i.e., away from the equator), this coefficient becomes negative
(due to the b2y2 term) and the wave-like solution
becomes an exponential solution (i.e., the wave solution
disappears).
•Equatorial
waves are trapped in the tropics.
•This
waveguide effect is due entirely to the variation
of Coriolis parameter with latitude.
