Your observing system, centered on the Equator in the Eastern Tropic Pacific, detects what you believe to be the passage of a Kelvin wave.
a) If this is indeed a Kelvin wave, at what rate (phase speed) and in what direction will it propagate? You may assume a shallow-water gravity wave propagating in the upper 40 meters of the water column.
b) What is its North-South e-folding scale?
c) Describe the balance of forces at play in the Kelvin wave.