So What is an El Niño, Anyway?
http://meteora.ucsd.edu/~pierce/elnino/whatis.html "The ocean is full of waves, but you might not know how many kinds of waves there are. There's one called a Rossby wave that is quite unlike the waves you see when you visit the beach. It's more like a distant cousin to a tidal wave."
Where Do Ocean Waves Come From?
http://oceanexplorer.noaa.gov/facts/waves.html "Waves are actually energy passing through the water, causing it to move in a circular motion, much like a buoy or seabird floating on the surface. When a wave encounters a surface object, the object appears to lurch forward and upward with the wave, but then falls down and back in an orbital rotation as the wave continues by, ending up in the same position as before the wave came by."