Ocean Swells Atlantic vs. Pacific


Why is the Pacific Ocean more swell consistent than the Atlantic Ocean? Is
there a real reason or is it just a meteorological phenomenon, pretty much,
why are there more storms/swell sources in the Pacific than in the Atlantic?


It is tempting to think that the Pacific, being a bigger ocean, has bigger waves. Wave size though is a function of wind speed and the distance over which that wind blows, called "reach". With a strong wind and long reach waves get high enough to start breaking which limits continued growth. Because of this, a hundred miles or so of reach is as good as a thousand, so wave size depends more on storm size than ocean size.

There are two components to most wind storms. One is the wind induced by local pressure differences like the circulating winds of a hurricane, or the sea breeze common in Summer afternoons in the U.S. The other is the overall circulation of the atmosphere induced by solar radiation and the planet's rotation. This latter circulation results in winds generally easterly between plus and minus 30 degrees of the equator, westerly between 30 and 60 degrees in both northern and southern hemisphere and easterly again between 60 degrees latitude and the poles.

The local pressure variation type winds tend to be stronger than the global winds so you may get an onshore wind on any coast. Onshore winds tend to enhance the size of waves making their way ashore from some disturbance at sea. Offshore winds tend to knock down waves coming ashore. In the U.S. the global wind component is onshore in the Pacific and off shore in the Atlantic, due to our location in latitude. This may account for somewhat better surf conditions on our pacific coast. Farther south we would expect less Pacific surf. In fact in Central America, where Balboa first saw the Pacific ocean it was so calm that he named it "Pacific". Of course had he arrived during a storm, the ocean might have a different name.

I suspect that the contour of the sea bottom has a lot to do with the surfing conditions. Waves lose energy when the interact with the bottom, so a gentle slope of the bottom would likely produce less surf for a given wave energy than would a steep slope.