The shallow, sunny Gulf of Mexico and Caribbean are the main place for heat energy entering the system.

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JC017073

this shows about three times as much heat entering the system in the Gulf and Caribbean (~1.2 petawatts) than is brought from the South Atlantic and Indian Ocean (0.4PW).

I know I could google it, I was just prodding the folks who drop nothing but an acronym to provide a little more explanation in with their post than just some uncommon letter string. The other posts that explain it weren’t there at the time of my post.