Enormous ‘rogue waves’ can appear out of nowhere(nationalgeographic.com)
nationalgeographic.com
Enormous ‘rogue waves’ can appear out of nowhere
https://www.nationalgeographic.com/science/article/mathematicians-may-soon-be-able-to-predict-enormous-rogue-waves
89 comments
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.
Sure, but tide and wave models generally cover a much larger area, such as whole coastal area's and over larger time spans. An example of such a model would be: https://www.youtube.com/watch?v=eN6CDaoMZ7U In the Netherlands this is used e.g. to determine when to close the storm surge barriers to protect the river delta area from flooding due to a tide+storm combination.
In contrast, the Next Ocean product is meant to model the direct area around a single ship, predicting minutes in advance with a second by second granularity. They are able to reuse the raw data coming from the navigation radar that is already installed on every sea-going ship. It uses the backscatter from water ripples to determine the wave field around the ship. Interestingly, for navigational purposes exactly this part of the data is considered noise and filtered out by the on board navigation system. (https://nextocean.nl/technology.php)
[I did some work on the software implementation for Next Ocean a couple of years back]
Anyway, neither type of model has anything to do with rogue waves.
In contrast, the Next Ocean product is meant to model the direct area around a single ship, predicting minutes in advance with a second by second granularity. They are able to reuse the raw data coming from the navigation radar that is already installed on every sea-going ship. It uses the backscatter from water ripples to determine the wave field around the ship. Interestingly, for navigational purposes exactly this part of the data is considered noise and filtered out by the on board navigation system. (https://nextocean.nl/technology.php)
[I did some work on the software implementation for Next Ocean a couple of years back]
Anyway, neither type of model has anything to do with rogue waves.
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.
This problem consists of a lot of subproblems, most of which are pretty well understood. For example how to translate the 6-dof motion of a ship to the vertical displacement of a heli platform on that ship is just some simple coordinate transforms. You don't gain anything by including that in the neural net. Potentially some data science techniques could be useful to handle some of the less understood submodels. Sort of like it is done in CFD with NN as a turbulence model within an existing PDE solver.
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.
This problem consists of a lot of subproblems, most of which are pretty well understood. For example how to translate the 6-dof motion of a ship to the vertical displacement of a heli platform on that ship is just some simple coordinate transforms. You don't gain anything by including that in the neural net. Potentially some data science techniques could be useful to handle some of the less understood submodels. Sort of like it is done in CFD with NN as a turbulence model within an existing PDE solver.
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?
Yes, I think ML could be useful at places where the current physics modelling falls short. The nowcasting rain example from DeepMind is in some respects pretty comparable with the Next Ocean wave prediction.
In the wave prediction case, wave propagation and dispersion is pretty well understood. But one could add ML-based nonlinear terms to the equations to capture everything we don't know. That has the possibility of giving better predictions.
In contrast with the rogue wave example, there is a lot of relevant input data (the radar backscatter) and the model output can be verified after the fact (the ship's 6-dof acceleration). What I was objecting to was the idea of: slap a ML model on the whole problem and call it a day.
In the wave prediction case, wave propagation and dispersion is pretty well understood. But one could add ML-based nonlinear terms to the equations to capture everything we don't know. That has the possibility of giving better predictions.
In contrast with the rogue wave example, there is a lot of relevant input data (the radar backscatter) and the model output can be verified after the fact (the ship's 6-dof acceleration). What I was objecting to was the idea of: slap a ML model on the whole problem and call it a day.
Other than the computational cost, why would you want to use stats when you have an analytic model right there?
To be fair, most analytical models working with data already incorporate a lot of 'data science' techniques. That does not have to be ML or NN, but could be as trivial as a least squares regression to fit you model to a set of observations that overdetermine the system of equations.
A more advanced example of a technique that was used before it was called data science is data assimilation (DA)[1]. Here you assume that you have observations (e.g. sensor data) that you want to use to inform the model, but they are noisy in some sense. With DA you take a set of observations at t=0 and fit a numerical model to that. Then you time-step the model to t=1 where you have new observations. The model and observations don't necessarily agree, but there is value in incorporating information from both. Based on e.g. your statistical description of the sensor noise, DA techniques give you the tools to combine data and models.
A good example of DA is 4DCOOL[2], combining temperature sensors in a datacenter with a CFD model. Because the model is physics-based, after some time you get a good idea of the temperature distribution in the whole room, even if you only have pretty sparse sensor data. (disclosure: I work for the company)
[1] https://en.wikipedia.org/wiki/Data_assimilation [2] https://www.vortech.nl/en/projects/a-digital-twin-for-the-in...
A more advanced example of a technique that was used before it was called data science is data assimilation (DA)[1]. Here you assume that you have observations (e.g. sensor data) that you want to use to inform the model, but they are noisy in some sense. With DA you take a set of observations at t=0 and fit a numerical model to that. Then you time-step the model to t=1 where you have new observations. The model and observations don't necessarily agree, but there is value in incorporating information from both. Based on e.g. your statistical description of the sensor noise, DA techniques give you the tools to combine data and models.
A good example of DA is 4DCOOL[2], combining temperature sensors in a datacenter with a CFD model. Because the model is physics-based, after some time you get a good idea of the temperature distribution in the whole room, even if you only have pretty sparse sensor data. (disclosure: I work for the company)
[1] https://en.wikipedia.org/wiki/Data_assimilation [2] https://www.vortech.nl/en/projects/a-digital-twin-for-the-in...
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.
> can we land skippy?
> one moment, just downloading this project off github
> just downloading few gigs of dependencies
“Cannot use import statement outside module”
> one moment, just downloading this project off github
> just downloading few gigs of dependencies
“Cannot use import statement outside module”
ESA satellites were used to find out more about rogue waves, and develop statistical models for prediction, shortly after they were first accurately measured in the 1990's.
The program was known as MaxWave;
https://www.soest.hawaii.edu/PubServices/2005pdfs/Rosenthal....
The program was known as MaxWave;
https://www.soest.hawaii.edu/PubServices/2005pdfs/Rosenthal....
Thank you, sounds interesting! Another source: https://www.esa.int/Applications/Observing_the_Earth/Ship-si...
Paste in console to read the article
document.querySelector('.Modal').remove();
document.querySelector('body').style.position='';
document.querySelector('body').style.overflowY='';FYI and unrelated to anything else...you can simply do `document.body` to get the `body`.
Or hit reader view.
There's a "Continue without accepting" button for me, but else I tend to do like this too (remove modal/iframe and some class/style on body)
I was wondering the other day, is there a generic "article-munging" firefox addon? Maybe you'd make rules per site how to make it readable. For example enable reader view automatically on some domains, pass some domains through 12ft.io (paywall remover) automatically and so on :)
Highly recommend “The Wave,” by Susan Casey, a nonfiction book that covers research into open ocean rogue waves, and also surfers attempting to predict and ride the largest breaking waves.
Looks like for surf there is a new record: https://youtu.be/zOYL15QOvWE
Also The Perfect Storm in which the author discusses rogue waves and contemplates that one took down the Andrea Gail.
The worst part of trying to read articles being published by very legitimate orgs like National Geographic are the mobile website decisions they allow their product teams to make.
In this case, just as I'm getting into the first few paragraphs of the paper some popup or override kicks in. Usually asking for a signup.
I think it's time to stop this destructive practice of attention grabbing instead of READING THE ARTICLE.
In this case, just as I'm getting into the first few paragraphs of the paper some popup or override kicks in. Usually asking for a signup.
I think it's time to stop this destructive practice of attention grabbing instead of READING THE ARTICLE.
I've mostly stopped reading websites on mobile because of this. On desktop I have various plugins and scripts in place to get rid of most of the annoyances.
It's not only subscription popups these days, there are also the goddamn GDPR popups (which don't even apply to me), Intercom popups, and ads of sorts that pop up separately from the newsletter signup.
Very often within a few seconds these mobile websites have 80% of the content covered by sometimes 2 or 3 separate annoyances, at which point I generally think it's not worth dealing with them anymore and just quit.
It's not only subscription popups these days, there are also the goddamn GDPR popups (which don't even apply to me), Intercom popups, and ads of sorts that pop up separately from the newsletter signup.
Very often within a few seconds these mobile websites have 80% of the content covered by sometimes 2 or 3 separate annoyances, at which point I generally think it's not worth dealing with them anymore and just quit.
Firefox mobile allows uBlock and noscript extensions.
I refuse to do actual browsing without NoScript in place. No ads, no popups, nothing.
Well, sometimes there's literally nothing, because SPA, but most of time it's just some kind of cover or body opacity set to 0. Totally worth the tradeoff on desktop and mobile. No ads, man. No fucking ads
Well, sometimes there's literally nothing, because SPA, but most of time it's just some kind of cover or body opacity set to 0. Totally worth the tradeoff on desktop and mobile. No ads, man. No fucking ads
I use NoScript and have for years but it sure gets exhausting to go to a site and find, in many cases, several dozen scripts that have to be "temp trusted" to get anywhere. I usually give up.
it's the process of trying to get paid for content, not attention grabbing
A good video about the overall topic: https://youtu.be/2ylOpbW1H-I
The topic reminded me of some fun wave tank videos like this one: https://www.youtube.com/watch?v=4384y5ZRRIs
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.
Is there a lot more to it than "random waves, it's less and less likely for them to overlap more and more, but sometimes that too happens"?
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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.
The problem to be understood is how you get a dozen waves constructively interfering over a long distance, not just popping up for a moment.
if a physics/acoustics class the professor set up a pair of speakers 30ft apart each playing a simple sine wave. The students then marched in front of the speakers, probably 50ft away, and as you walked you could clearly hear where the constructive and destructive interference was happening.
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)
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 originally discussed the heights discussed were considered to be such that they were a 1 in 10'000 year probability, and there wasn't anyone living who could provide first hand evidence, just records of ships going missing and "rumors" amongst sailors.
When rogue waves were originally discussed the heights discussed were considered to be such that they were a 1 in 10'000 year probability, and there wasn't anyone living who could provide first hand evidence, just records of ships going missing and "rumors" amongst sailors.
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
[0] https://en.m.wikipedia.org/wiki/Green_flash
The green flash lasts for many minutes near equinox at the poles.
I have corresponded with someone who camps in Antarctica (it takes all kinds!) and has watched it happen.
Seeing a rogue wave and not dying has to be a lot rarer than just seeing one.
I have corresponded with someone who camps in Antarctica (it takes all kinds!) and has watched it happen.
Seeing a rogue wave and not dying has to be a lot rarer than just seeing one.
Well from my understanding the core problem is the statistical models used to calculate their probability were completely wrong.
So we had “hard” math “proving” they were once-in-a-million-years unlikely, and that lasted until we had overwhelming observational evidence to the contrary (in this case buoy data)
So we had “hard” math “proving” they were once-in-a-million-years unlikely, and that lasted until we had overwhelming observational evidence to the contrary (in this case buoy data)
> I really don't understand why monster waves seem so mysterious to scientists.
Because the explanation isn’t complete. A surfer seeing something 10 seconds beforehand and reacting to it has nothing to do with why it was occurring at all.
Because the explanation isn’t complete. A surfer seeing something 10 seconds beforehand and reacting to it has nothing to do with why it was occurring at all.
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.
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.
ΜΙΤ also did a similar research years ago for Monster waves which is exactly the same as rogue waves (i guess there is no spesific name about it) they are really important for maritime industry, they're in theory for now, but some will claim that can actually have a sensor like that, well they dont, but its funny to waste time with sales people.
I watched a documentary about them ages ago where the demonstrated how rogue waves can form by natural processes as different directional (terminology most likely wrong) waves cross each other. Wish I could remember enough about it to post a link.
You might be thinking of “cross sea”: https://en.m.wikipedia.org/wiki/Cross_sea
The math of rogue waves is discussed at https://community.wolfram.com/groups/-/m/t/2399430
That page completely locked up Chrome on my Pixel 4a.
https://origin.wolframcdn.com/consent/cookie-consent.php
I think it's because of a cert issue? Locks up my computer, too. I'm surprised Chrome doesn't kill the runaway code.
I think it's because of a cert issue? Locks up my computer, too. I'm surprised Chrome doesn't kill the runaway code.
Same here, Vivaldi on Pixel 3a. Plus a pay wall on the OP site. It would be nice to participate in the conversation.
Fwiw, it works in Firefox on Android.
I'm not a fan of FF for Android after they removed extensions and other UX negatives.
The extensions are still kind-of there (there are ways you can use them), but yeah, it sucks.
Owned a 40 foot sailboat with 5+ feet of freeboard. Waves refract going around islands (lee side has weird waves even if less wind), through currents and over shoaling. The Strait of Juan de Fuca is sometimes referred to as Juan he Fuck You because of the "haystacks". You see them: "oh there was a haystack! did you see it?"
Ran into one once; two feet of green water rolled across the deck. And then it was gone.
Ran into one once; two feet of green water rolled across the deck. And then it was gone.
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.
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.
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So you need a non-linear medium.
Like a plasma. Those exist in nature.
Like a plasma. Those exist in nature.
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In the Baltic (to take an example), I would expect that altho it is a large sea, its relatively small size (compared to the open sea) and its shallowness would not provide the conditions for the formation of rogue waves.
Mathematics has known about solitons since 1844.
I thought it was well known that rogue waves are Peregrine solitons? Few other models can explain their observed behavior as well.
I thought it was well known that rogue waves are Peregrine solitons? Few other models can explain their observed behavior as well.
[deleted]
Yep.
The "traditional view" is basically a linear model view.
The new understand involves nonlinear models.
The "traditional view" is basically a linear model view.
The new understand involves nonlinear models.
Firefox on Android. Page freezes at load and I cannot scroll.
It caused me to take a bad fall at sea one time, rogue waves do happen and they are horrific.
This article is hard to read, like most media outlets these days. Why do they run so many scripts, that call other scripts, that call other scripts...? Here's the nutshell anyway, via Firefox + NoScript + Ublock Origin and selectively blocking certain elements:
> "Scientists have since figured out that unlike tsunamis, which are large waves produced by a sudden displacement of water from an event such as an earthquake or landslide, rogue waves form due to a chance combination of wave movements through the ocean."
> "Two main mathematical theories have emerged to explain the wave movements that spawn rogue waves: Linear addition and nonlinear focusing. Linear addition assumes that waves travel through the ocean at different speeds, and when they overlap, they can strengthen into a rogue wave. Nonlinear focusing assumes waves travel in groups and can lend energy to one another, which sometimes spawns a rogue wave."
> "One reason for the uncertainty is that rogue waves are rare. Even now, there’s a dearth of quality tracking data."
For those not at sea in a boat, but walking along a coastline, the practical thing to keep in mind is that just because the ground is dry, doesn't mean a sneaker wave can't come along once an hour, so be careful and keep your eyes on the ocean.
> "Scientists have since figured out that unlike tsunamis, which are large waves produced by a sudden displacement of water from an event such as an earthquake or landslide, rogue waves form due to a chance combination of wave movements through the ocean."
> "Two main mathematical theories have emerged to explain the wave movements that spawn rogue waves: Linear addition and nonlinear focusing. Linear addition assumes that waves travel through the ocean at different speeds, and when they overlap, they can strengthen into a rogue wave. Nonlinear focusing assumes waves travel in groups and can lend energy to one another, which sometimes spawns a rogue wave."
> "One reason for the uncertainty is that rogue waves are rare. Even now, there’s a dearth of quality tracking data."
For those not at sea in a boat, but walking along a coastline, the practical thing to keep in mind is that just because the ground is dry, doesn't mean a sneaker wave can't come along once an hour, so be careful and keep your eyes on the ocean.
> Why do they run so many scripts, that call other scripts, that call other scripts...?
To answer your question with a question, how much money did you take out of your pocket and give to National Geographic in exchange for reading the article?
To answer your question with a question, how much money did you take out of your pocket and give to National Geographic in exchange for reading the article?
Well since their website is unusable (never mind the fact that a nature magazine has turned to culture war) I won’t be giving them anything.
The worst part is when you pay for a 12 month subscription and they cancel it after 11 and ask you to renew.
Mostly relevant if if you have small children playing at the beach in an area known for Riptide. Sneaker waves are a big issue if you're doing things like fishing from a Breakwater like tide pooling and don't know how to swim.
I think consideration of the environment you're putting yourself into is vastly more important than constant vigilance
I think consideration of the environment you're putting yourself into is vastly more important than constant vigilance
> Sneaker waves are a big issue if you're doing things like fishing from a Breakwater like tide pooling and don't know how to swim.
> I think consideration of the environment you're putting yourself into is vastly more important than constant vigilance
This is one of those things that blows my mind every time it comes up, both how many people don't know how to swim at all and how many of those people either work or play near water deep enough to require swimming if you end up in it.
I get not knowing how to swim if one didn't have access to pools and such in their youth, but if one enjoys waterfront leisure activities or works around bodies of water regularly you'd think it'd be worth spending a few hours learning the absolute basics of not dying if you fall in.
> I think consideration of the environment you're putting yourself into is vastly more important than constant vigilance
This is one of those things that blows my mind every time it comes up, both how many people don't know how to swim at all and how many of those people either work or play near water deep enough to require swimming if you end up in it.
I get not knowing how to swim if one didn't have access to pools and such in their youth, but if one enjoys waterfront leisure activities or works around bodies of water regularly you'd think it'd be worth spending a few hours learning the absolute basics of not dying if you fall in.
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Non subscription link?
Turning off CSS and JavaScript lets you read the whole article. Possibly just turning on reader mode will do that too.
there's archive.org https://web.archive.org/web/20220611061036/https://www.natio... but it also has the subscription popup there, a pattern I've been noticing more and more.
on edit: maybe archive.org should have reading options menu somewhere, so you can say read this without JS, reader mode, etc.
on edit: maybe archive.org should have reading options menu somewhere, so you can say read this without JS, reader mode, etc.
Looks great in a text-only browser. Easy to read. No popups. Ever.
Use reader mode. Worked for me in Safari on desktop, anyway.
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stereocodes(1)
I wager the same process of discovery is about to happen for UFOs.
As sensors become more capable we will see more and more hard data. This will move the needle on scientific opinion and that in turn will spur research.
The two phenomena may even be related - rogue waves in the fields of QFT...
The two phenomena may even be related - rogue waves in the fields of QFT...
Why is this being downvoted?
> Scientific doubts about these mysterious, giant waves were not completely dispelled until 1995, when a rogue wave hit the Draupner oil rig, a natural gas platform in the North Sea off the coast of Norway.
> Scientific doubts about these mysterious, giant waves were not completely dispelled until 1995, when a rogue wave hit the Draupner oil rig, a natural gas platform in the North Sea off the coast of Norway.
Because people, by and large, are simple ego driven things. The word UFO is associated with people they deem less valuable than themselves, therefore they reflexively distance themselves from it. They are not aware enough to observe their own motivations so they invent them. Spinning logic to support their emotional reactions. They are also do not read widely enough to have observed the change that is happening in the discussion of UFO phenomena.
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 in the article, a challenging amount of computation to do in a real-time prediction setting.