Eastward Kelvin Waves

I read a recent issue of Science which hypothesized an explanation of why Kelvin waves always move eastward and I realized that I did not even know what Kelvin waves are, much less what direction they move.  Why does that even matter?  While I think of myself as a person who believes in and supports science, there are very large gaps in my knowledge, and because I live in a country where climate deniers are in charge of government, it is more important to be an educated voter.

So here goes.  Equatorial Kelvin waves occur constantly in Earth's atmosphere and ocean. They constitute an isolated and powerful component of the observed atmospheric wave spectrum, whereas oceanic Kelvin waves drive up- and downwelling in the Pacific Ocean thermocline, which affects the El Niño–Southern Oscillation. In the atmosphere, Kelvin waves are initiated by and coupled to convective activity (storm systems), mostly over the Indian and the western Pacific Oceans.  So as we have more dramatic temperature changes, Kelvin waves will play more of a role in weather.