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Enormous ‘rogue waves’ can appear out of nowhere

nationalgeographic.com

71–80 of 90 posts

Re: Enormous ‘rogue waves’ can appear out of nowhere

#71

Could this be used for electromagnetic (and other) waves as well? I suppose the principles are similar for a medium in which oscillations move into some direction(s) etc.

The electromagnetic equations are linear, whereas the fluid dynamic ones are non-linear. This difference is crucial for this phenomenon.

[deleted]

Re: Enormous ‘rogue waves’ can appear out of nowhere

#72

This is a commercially available product for wave prediction on ships: https://nextocean.nl/wavepredictor.php Not specifically meant for rogue waves though, but rather to predict calm streaks in the waves affecting the ships motion. This is useful, e.g. when landing a helicopter or transferring cargo or persons to another ship while at sea. I can confirm that there is a lot of interesting math involved and, as noted…

There are also open source tide and wave models, which is what researchers use and are fairly accurate. Not sure how much this commercial product differs, but I know the Navy etc. use the open source ones with in house adjustments.

> can we land skippy?

> one moment, just downloading this project off github

> just downloading few gigs of dependencies

“Cannot use import statement outside module”

Re: Enormous ‘rogue waves’ can appear out of nowhere

#74
post #39

Earlier quoted context omitted.

I wonder to what extent all the mathematical modeling can be replaced by modern run-of-the-mill data science techniques.

Other than the computational cost, why would you want to use stats when you have an analytic model right there?

Flexibility: the problem might change in ways that are difficult to model. Also, the model might capture "unknown unknowns". And before you say that you need massive amounts of data: so does an analytical model, assuming you want to verify it.

Re: Enormous ‘rogue waves’ can appear out of nowhere

#77
post #26

If you've ever double bounced someone on a trampoline it's the same effect. Constructive interference is awesome.

The causes of rogue waves are not understood.

Wobble a glass of water just the right way and you will get rogue waves from constructive interference. The problem is predicting them in the ocean.

Re: Enormous ‘rogue waves’ can appear out of nowhere

#78
post #39

Earlier quoted context omitted.

I wonder to what extent all the mathematical modeling can be replaced by modern run-of-the-mill data science techniques.

My guess would be: not that much. But I work in the field of numerical mathematics and computational physics, so I could have some bias. :-D The more nuanced answer would be that taking the raw radar data as input to e.g. a neural network and train that to output the predicted timeseries of future ship motion is not feasible. It would take a giant network and too much compute to train for very unreliable results. Thi…

Am an ML engineer with no experience on this subject. Do you think research like deep mind has done with now-casting could be useful here?

Re: Enormous ‘rogue waves’ can appear out of nowhere

#79

Surfers are very familiar with how two waves that come in different angles combine into a very high wave at the intersection. I really don't understand why monster waves seem so mysterious to scientists. I'm certain they happen all the time but no one is there to observe them except for the occasional unlucky sailor. https://en.wikipedia.org/wiki/The_Wedge_(surfing)

Because what you're describing isn't a "rogue wave," it's just a slightly bigger wave. I'm not a surfer and am just a person who's been swimming in the sea a handful of times and I've seen this phenomenom. The rogue waves being described are incredibly rare to the point that sailors who have sailed 5000 hours have never encountered one and are sometimes talked about as though they are mythical. When rogue waves were…

When I was in the navy, the old Grizzly senior dudes would talk about rogue waves like the green flash [0]; some insisted they knew someone who saw one and others were sure that both were amongst the oldest sailor jokes in existence. It seems both phenomenons are real!

[0] https://en.m.wikipedia.org/wiki/Green_flash

Re: Enormous ‘rogue waves’ can appear out of nowhere

#80
post #66

Surfers are very familiar with how two waves that come in different angles combine into a very high wave at the intersection. I really don't understand why monster waves seem so mysterious to scientists. I'm certain they happen all the time but no one is there to observe them except for the occasional unlucky sailor. https://en.wikipedia.org/wiki/The_Wedge_(surfing)

I mean, there was just an article about how scientists discovered that worms travel after a rain, which is something I figured out when I was ten. Science has a lot of blind spots. Surfers and children aren’t high on the list of people to consult or observe. Nor for a long time was folk medicine.

I spent a lot of time on the ocean surfing and then in the Navy. I've seen a lot of strange wave behavior and have been fascinated by it, so I suppose rouge waves don't seem odd to me in a chaotic fluid situation.
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