What is causing that whistle/hum (in A flat) in the Caribbean?
Space.com has a discussion and embedded video that won't post.
here is another video that discusses the phenomenum:
Gizmodo has more in less scientific language.
When those waves strike the western boundary of the basin, they die out and reappear at the eastern edge.
This phenomenon, flashily named the “Rossy wormhole,” was first described several years back. Scientists now know that waves of certain shapes and sizes will resonate when they hit that western wall, just as certain frequencies resonate when you blow into a whistle. In both cases, the resonant frequency produces a sound.
But because the basin of the Caribbean Sea is so vast compared with an actual whistle, the resonant frequency is extremely low. It takes 120 days for waves to propagate east to west in the basin, yielding an A-flat tone that’s roughly 30 octaves below the bottom of a piano. A pitched-up version of that excessively eerie sound can be heard in the clip above.
Dubbed the “Rossby Whistle” in a paper accepted for publication in Geophysical Research Letters, the phenomenon can be detected from space owing to fluctuations in Earth’s gravity field as pressure changes propagate across the entire basin.
hmm...maybe someone is trying to tell us something: