# Talk:Wind wave

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 September 30, 2006 Featured article candidate Not promoted

## Old comments and discussion

Does the amount of water affect the size of the wave?—Preceding unsigned comment added by 67.79.42.254 (talkcontribs) 17:57, 13 December 2005

Certainly not. Water will deform continuously under shear so the amount (Volume basis) of water doesn't have a role to play in the size of the waves.—Preceding unsigned comment added by Samueldevadoss (talkcontribs) 11:23, 7 February 2006

The image alignment of this page is somewhat odd. Could it be changed so that the text is next to the images?—Preceding unsigned comment added by Fods12 (talkcontribs) 04:50, 1 January 2006

Is a water wave's speed always the same (even if frequency changes) except for when depth changes? I read this formula: v=root(g x d) d=depth—Preceding unsigned comment added by 86.132.132.180 (talkcontribs) 22:13, 13 March 2006

There is equations that describe how ocean waves move through deep water. Along high energy sandy coastlines there is a "depth of closure" that is about equal to the 1:100 year wave height - for the Gold Coast around 18m deep. Beyond this point waves move with the characteristics of deep water waves. As such waves approach the shore they change their speed as the velocities under the waves start feeling the bottom. For surfing typically there is an obstruction that is at an angle to the incoming waves - some of the wave feels the obstruction and commences to break - the wave then bends into the break point feeding in more energy. If the angles are right you get a surfing wave. If it breaks too fast it closes out and you can't surf it.—Preceding unsigned comment added by 203.3.64.1 (talkcontribs) 01:14, 18 December 2006
What do you (anonymous contributor) mean by 'the amount of water'? Even the addition 'volume basis' doesn't ring a bell with me if it comes to propagation of waves. The formula is about the maximum speed of waves traveling through a basin with depth 'd'. You may already have found that waves with smaller wavelenghts travel at less speed than waves with greater wavelenghts but this rule only applies for waves that don't touch the bottom of the basin (that is to say waves with a wavelength less than twice the depth of the basin). Wikiklaas 22:44, 13 March 2006 (UTC)
In general the speed of the wave is a function of frequency and depth. This dependence on frequency goes away in shallow water. Jmkstrat 13:54, 28 May 2007 (UTC)

I do not like the "elliptical trajectory" diagram. Trajectories are never elongated in the vertical, as drawn, but always in the horizontal, and only when the water is shallow. Also, the dashed red trajectory should not extend higher than the tops of the crests. This same diagram is part of the Wave article, and I think it should also be changed there. Rracecarr 23:43, 10 May 2006 (UTC)

## too many images, not enough text

images are taking over this page, perhaps they could be culled a bit, or more written to increase the words:image ratio?--naught101 06:08, 24 May 2006 (UTC)

I agree, there are way too many images in this article. It's been bothering me for quite a while, however I haven't had time to do anything about it. Adding more text isn't going to solve the problem though, the images are mostly out-of-context (at least misplaced). At the moment they're just adding fluff. If you want to do anything about it, I'll back you up. --Bruce 13:04, 25 May 2006 (UTC)

With that background I'll ask before making this change. Would my picture Waveface.jpg add something to the article? I believe it adds value in that it shows the shallow ocean floor where the wave breaks and how sand is being caught by and sucked into the wave when it breaks - and that this visually explains something fundamental about waves to the reader - but I don't want to add more pictures to this article if it is already overloaded. Elmats 12:32, 26 March 2007 (UTC)

## Remove stub?

I added quite a bit to the page, in a little more layman's terms. Anyone vote for removing the stub tag? LACameraman 08:43, 24 May 2006 (UTC)

I noticed that the content you added was copied from "Anatomy of a Wave - By Jay Holben" (Google Cache). Are you Jay Holben? --Bruce 13:04, 25 May 2006 (UTC)

I am. I figured this didn't fall under the original research as that article was thoroughly researched. Also no copyright violation as I'm the original author of the original article. Hope that it helped to round out the article a bit. LACameraman 06:21, 26 May 2006 (UTC)

## A new image

A particle motion in a ocean wave.
A=At deep water
B=At shallow water. The circular movement of a surface particle becomes eliptical with decreasing depth
1= Progression of wave
2= Crest
3= Trough

This is a modification of the image. I think it is better and more correct than the original. I've made it only for shallow water, but it is easy to do it for deep water too. I've chosen the numbers to facilitate the use in any language.(Internationalization)

Zimbres 21:08, 8 June 2006 (UTC)

Yes, definitely an improvement. Rracecarr 08:38, 9 June 2006 (UTC)
I concur, the illustration is clearer, but I question the reference to shallow or deep water. The expanded elliptical path of the object will be determined by wave steepness, not necessarily by depth of the water. If you're referring to particle motion at depth, that is an interesting note to make, but has to bearing on an article on surface waves. The illustration itself, however, is better than the existing one. LACameraman 09:58, 9 June 2006 (UTC)
Not sure what you mean, LACamera. In deep water the particle orbits are circles, and in shallow water they are squashed into ellipses. This does not depend on wave steepness. However, for steep waves, the orbits are no longer closed: water particles end up displaced a little in the direction of travel of the wave.Rracecarr 17:08, 9 June 2006 (UTC)
I've made one more modification in the picture. Now I think it is good for the article.Zimbres 21:53, 9 June 2006 (UTC)
The article is about ocean surface waves - not water particle movement in shallow or deep water - but movement on the surface of the ocean. The reference to particle movement at any depth, except on the surface, is not relevant to this article. The image is clearer than the existing one, but the references to different particle movement patterns at depth should be removed. LACameraman 00:33, 10 June 2006 (UTC)

Dear Lacameraman, one can't understanding how an ocean surface wave works if he doesn't understand its whole movement, including the particles movement. How explain, for example, the origin of the surf zone near the beaches? How understanding the wave breaking process? The ocean wave movement is made possible by small movements of the water molecules and the diagram is about that. Zimbres 14:34, 10 June 2006 (UTC)
Maybe it should be added that, in shallow water, the major axis of the ellipse tends to align itself with the floor (Biesel’s theory). Inike 13:32, 11 June 2006 (UTC)
I like new picture; it's a big improvement. I do have a couple suggestions. First, it might help to show the that for the shallow wave, the bottom of the ocean is at the "B". You might want to split the picture into two halves, one with a bottom and one without. Also, for the deep-water waves, the circle should decrease exponentially it size, rather than just disappear. But it would be pretty hard to make the difference clear in the picture, so you can ignore that :) Finally, the water surface should be should look more sinusoidal; the "traditional" wave shape is due to breaking, which is beyond the scope of that particular diagram. Bennetto 23:38, 4 July 2006 (UTC)
The picture is misleading. The results you quote about the particle paths being circular for infinite depth and elliptical for finite depth are only true in the LINEARISED limit for a monochromatic wave (the Stokes drift is a higher-order correction). Given that this is the case, the free surface shape of the picture is misleading. In the linear limit the waves shapes are simply sinusoidal, rather than having peaked crests and flattened troughs. 21 Feb 2007 —The preceding unsigned comment was added by 81.155.217.252 (talk) 20:57, 21 February 2007 (UTC).

## Types of waves section

The 'Types of waves' section is out of tune with the start of the article. It is written in a 'popular' style and IMO should be rewritten or deleted. MH 20:00, 19 June 2006 (UTC)

As the author of the section in question, I would (of course) argue against deletion. The scientific section of this article, although excellent in and of itself, does not cover the topic nearly as completely without the section on Types of Waves. I do agree that the tone is different, but it is extremely difficult to compete with such a complex and hardcore mathematical approach, which I feel will alienate the majority of readers of this article. I am, of course, open to revisions in the section I added. If you feel you can match the tone and keep the information, please have my blessing. LACameraman 22:45, 19 June 2006 (UTC)
I believe both comments areappropriate. In preparation for a surfing weekend, I studied and did a sort-of rewrite on the (already pretty good) section, and will dl the box on the page. Sfahey 04:05, 22 August 2006 (UTC)

Ocean waves are inherently mathematical. They are one of the few phenomena described adequately by linear math. The math isn't that hard. User:jmkstrat

## Fetch

Coorect me if i am wrong, but doesnt a longer fectch produce a larger wave, therefore that would be a destructive wave. Also a shorter fetch, makes a constructive wave because the wave has less energy to drag sediment back during the backswash. 88.108.26.22 13:42, 23 September 2006 (UTC)

This seems correct. Does the article say otherwise? Sfahey 02:20, 25 September 2006 (UTC)

Yes it does, it says that constructive waves are formed over a longer fetch and that a destructive wave is formed with a short fetch razza 14:54, 7 October 2006 (UTC)

## Eighth Wave Question

I've always wondered why every eighth wave striking land is always the biggest. I can't find an answer anywhere. Does anybody know? I'd be grateful if someone could tell me on my talk page. Thanks! Robinoke 14:12, 1 October 2006 (UTC)

Waves tend to travel in groups. These waves have different frequencies and thus, when added together to create the free surface elevation, constructively and destructively interfere. The "eighth wave" (it may or may not actually be eight) is the largest wave of that group, being entirely due to constructive interference. As the waves enter shallow water, and their speed is no longer that dependent on frequency, they travel as a "locked" group, which is why it seems that the eighth wave is always the largest. Jmkstrat 13:54, 28 May 2007 (UTC)

## Phase Velocity

The article describes phase velocity as the speed of movement of changes in shape. I believe this is not quite correct. The phase velocity is the speed of propogation of a phase change (ie change in phase angle). Shape changes can occur from amplitude (group velocity) and frequency of source. (Edit: Ill come back in a few days and modify it if there is no comment on this.) User A1 08:26, 4 October 2006 (UTC)

## opening line

Apparently Ocean surface waves are surface waves that occur at the surface of an ocean. I changed this, hopefully to make it sound better and be a little bit less of a circular definition. Tell me what you think User A1 06:28, 1 December 2006 (UTC)

I think the correct terminology is "surface gravity wave(s)", as gravity is the restorative mechanism which enables the wave to propagate. This differentiates them from other wave phenomena such as "capillary waves", which are in fact surface waves but are driven by surface tension as the restorative mechanism. One can also observe capillary waves on the ocean surface but it is my understanding that this article refers to surface gravity waves. Michael.morristhomas 18:58, 18 December 2006 (UTC)

## "Clapitus"

Can anyone shed any light on the origin and extent of use of the kayaking term Clapitus -- in that article? Thanks —The preceding unsigned comment was added by Clapitor creator (talkcontribs) 04:56, 19 January 2007 (UTC).

Clapitus is probably a miss-spelling of the French word clapotis. Kraaiennest (talk) 12:09, 4 February 2008 (UTC)

## Wave close up

Hi,

I think there is no need for the wave close up in the section that you added it to. It does little to increase the reader's understanding of the types of wind waves possible. However the image is quite reasonable and obviously good effort has been expended in achieving it. Finally can you digitally edit (maybe just crop) the image to remove the giant date stamp on it? It detracts from the quality of the image (IMHO). Thanks, User A1 02:22, 1 June 2007 (UTC)

## Merge in waves and shallow water

What do we think about merging the content of Waves and shallow water into this article? User A1 16:06, 14 September 2007 (UTC)

## What about soliton waves?

The article Soliton mentions that solitary waves were first observed in water, in a barge canal by John Scott Russell. Here's a website about it. Should this be added to the article? How do soliton waves differ from ordinary water waves? --ChetvornoTALK 00:53, 4 February 2008 (UTC)

Solitons only appear as surface waves in shallow water. In deep water, surface waves do not travel alone but in wave groups. On the other hand, solitons (or solitary waves) travel as a single wave of unchanged form.
Regarding the inclusion in this article: first, in my opinion, the name of this article is not so appropriate, since the phenomenon of waves on a water surface not only occurs in oceans, but in many open waters, like seas, lakes, rivers, etc. In this respect it is already significant that most photographs in this article are of breaking waves on beaches. No pictures of waves in the open ocean are present.
With the present name, I think solitons should not be included, since they do not appear on the surface of the ocean (although solitons may appear as internal waves on the interface between ocean layers of different density). Kraaiennest (talk) 12:04, 4 February 2008 (UTC)

## are waves only in the ocean_

what determines whether there'll be waves in a place of water or not... in some rivers there seems to be waves or is that an innacuracey... do bays have waves... do rivers and canals... what about the thing with the moon... sorry my question mark on the keypad doesnt work... —Preceding unsigned comment added by 190.49.19.130 (talk) 18:07, 24 March 2008 (UTC)

In my opinion, you are perfectly right. Waves on a water surface also occur in rivers, lakes, canals and bathtubs, and they all obey to the same equations. The name of this article has not been well chosen. Crowsnest (talk) 20:44, 24 March 2008 (UTC)

## Dangerous Waves

Waves poise a serious danger to people and property. Even non-Tsunamis are quite deadly. If the page is to be a FA it should have a section detailing the dangers. I have started edits, but can use other editors.--Lemmey talk 23:31, 4 May 2008 (UTC)

Waves may be dangerous, as well be fun (surfing), provide energy (wave power), give rise to forces, create beach erosion or accretion (littoral drift), etc. You are free to start a new section on wave effects, dangers and applications.
But this is an encyclopedia, and the added news item, how tragic it may be, is not encyclopedic. So I removed it. Crowsnest (talk) 07:19, 5 May 2008 (UTC)

## Particle trajectories

The edits by InIn9393 (talk) on April 28 and May 4 are reverted by me, since they are not encyclopedic, using definitions which are uncommon to the literature on the subject, and due to the chosen definitions come to erroneous conclusions regarding the direction of the particle drift motion. The reference used by InIn1993 is a paper by Constantin (2006), Inventiones Mathematicae, vol. 166, p. 523. In the edits by InIn93 also references therein to earlier papers by Constantin seem to be referred.

1. According to the literature, trajectories of particles are closed ellipses within the framework of linear wave theory (see for instance: Landau & Lifshitz, vol. 6, 1986, p. 33; Lamb, 1994, p. 367; Phillips, 1977, p. 44; and many others). They all consistently apply the same linear theory, valid for infinitesimal-amplitude waves, also to computing the particle trajectories. In contrast, Constantin uses a nonlinear mapping to compute the particle trajectories for finite-amplitude waves, while using the flow field of linear wave theory. He concludes on grounds of this inconsistent (mixed linear and nonlinear) reasoning, that particle trajectories are not closed in linear theory, i.e. that after one wave period (as experienced by the particle) a particle ends at another position than where it started.
2. The fact that particle trajectories are not closed ellipses for nonlinear waves, was already established by Stokes (1847), using a (consistent) second-order (in wave amplitude) theory. This was extended to fully nonlinear waves in the 70's and 80's by many authors (e.g. Longuet-Higgins 1979, 1986; Williams 1981, 1985). They were well aware, that the Stokes drift in a nonlinear wave is due to the fact that the wave period experienced by a fluid particle in a Lagrangian frame of reference is different to the period of the surface elevation in an Eulerian frame of reference.
3. Constantin (2006) neglects that for nonlinear waves the definition of the wave phase speed is by no means unambiguous. In theory, any Galilean frame of reference may be used, some more reasonable than others. While Constantin poses on p. 526: "This leads naturally to Stokes' definition of the wave speed as the mean velocity in the moving frame of reference in which the wave is stationary.", Stokes (1847) poses a second definition which seems equally reasonable to him, i.e. the mean mass-transport velocity (depth-integrated horizontal-volume flux, averaged over a wave length and divided by the mean Eulerian depth), see p. 203 of his Papers, Vol. I (a reprint of the 1947 paper) . This definition of phase speed is at least equally valid, and in some respects even more natural (since for instance in laboratory wave flumes the mass flux is zero, and also for waves approaching normally to the coast the mean mass flux is zero).
In case of Stokes' 2nd definition of wave celerity, i.e. a zero-mean mass flux, the fluid particles near the free surface drift in the wave propagation direction, while those near the bed drift in the opposite direction (contrary to the Constantin paper). This is the normal situation in a laboratory wave flume, for a wave made by a moving partition.
4. The "Science of waves" section is brief, and the inserted discussions on theories of particle orbits are out of proportion, in length, in depth and in relative importance for the subject, as compared to the rest of the section.

Crowsnest (talk) 14:25, 6 May 2008 (UTC)

Dear colleagues, it seems that there is a widely held misunderstanding about this topic. It is correct that the orbits are not closed for non-linear waves, but this is also true for linear waves, although this requires a careful calculation (Stokes drift). Indeed the mean drift of water particles is related to the wave momentum, which, just like the wave energy, is a nonlinear property, proportional to the amplitude squared. I could expand on this here but you may otherwise consult Phillips (1977). I would thus suggest that the page is corrected accordingly. Ardhuin (talk) 08:23, 16 July 2011 (UTC)

## Gallery

This article consisted of too many pictures for their own sake -- these images do not connect to the article prose in any way. I have removed them for this reason. If a gallery is desried, it may be an idea to add an external link to a creative commons gallery. User A1 (talk) 05:15, 10 August 2008 (UTC)

## Title

The wind waves described in this article occur on lakes and large rivers as well as oceans. Ocean surface waves also encompasses Kelvin waves, Rossby waves, tidal waves etc. which are not mentioned (although there is a brief mention of tsunamis, which does not fit with the rest of the article). Maybe this article should be titled "wind waves"? And a separate article on "Water waves" should describe the many different types of water wave, of which "Wind waves" is a sub-set. "Ocean surface waves" is also sub-set. —Preceding unsigned comment added by 86.142.208.199 (talk) 20:41, 26 October 2008 (UTC)

You are raising a very good point. I agree with you that the name is not in accordance with the content. But I think more thought is needed on a proper name for this article, as well as a for other, related articles. -- Crowsnest (talk) 21:25, 26 October 2008 (UTC)
• I agree with the proposal. "Ocean wind waves" or just "Wind waves" (if we want to consider lakes and rivers) would be more accurate. Rossby waves, tides, etc. are of a different nature. -- Alvesgaspar (talk) 21:48, 26 October 2008 (UTC)
The danger of "wind waves" is that "swell" may become a bit orphaned. Some references consider "wind waves" and "swell" different types of waves. So how about: "Wind-generated waves". I prefer to drop "ocean", since they equally well occur in e.g. lakes, rivers, canals, swimming pools. -- Crowsnest (talk) 22:56, 26 October 2008 (UTC)
• I prefer with "Wind waves", as this is the (almost) universal scientific designation for both "sea" and "swell" waves, at least since Kinsman (1965) book (and probably much before that) -- Alvesgaspar (talk) 23:22, 26 October 2008 (UTC)
"Wind wave", although more common, may give confusion since there are books and papers not sharing "swell" under "wind waves". Although Kinsman is a well-known reference, it is not the only one. On Google Scholar, "wind waves" gives about 16,000 hits and "wind-generated waves" about 3,700, so it also is a common description of the phenomenon.
In my opinion, "wind-generated wave" is more precise, see WP:PRECISION, and has my preference. We also have to consider (whatever name we choose) the use of plurals for naming articles. -- Crowsnest (talk) 00:28, 27 October 2008 (UTC)
Kinsman also frequently uses terms like "wind-generated ocean surface waves", "wind-generated gravity waves" and "wind-generated waves" in his book. -- Crowsnest (talk) 00:43, 27 October 2008 (UTC)
• I think that "Wind wave" is better than "wind-generated waves" even though it arguably leaves out swell, because it is easier to link within text and follows wiki guidelines for short concise titles. The text in the introduction can explain that swell is included as a wind-generated wave. Tasomerville (talk) 18:17, 30 October 2008 (UTC)

Regarding the name and available articles: there is no general article on "surface gravity wave" (they are mentioned in gravity wave, about 1000 hits on this phrase on Google Scholar), the common (scientific) name for these waves, irrespective on how they are generated. They also include tsunamis and seiches, tides as forced gravity waves, and the wave swimming pool. So what would a good structure be? Have a separate article on "surface gravity wave", focussing on the scientific aspects of these waves, and this article as the wind-generated waves (incl. their generation by wind)? -- Crowsnest (talk) 09:26, 11 November 2008 (UTC)

I moved Ocean surface wave to Wind wave, and created a redirect Wind generated wave. And some more redirects which seemed plausible to me. -- Crowsnest (talk) 11:38, 28 February 2009 (UTC)

## Overlap with Swell (ocean)

Lots of, esp. wrt physics and generation. Wegesrand (talk) 10:08, 19 July 2016 (UTC)

## Needs references to Beaufort scale

The article needs to define the terms referenced at Beaufort scale since sailors use wave appearance to help distinguish wind speeds (e.g., "whitecaps" and "white horses"). Also proper wikilinks both ways and mentions at the disambiguation pages for each of the terms themselves. Lots of work; sorry! --72.70.31.129 (talk) 18:04, 18 July 2009 (UTC)

## List of wave topics

Strangely, this article was not in the list of wave topics until I put it there a few seconds ago. If anyone know of others that are not listed but should be, could they add those too? Michael Hardy (talk) 20:20, 18 September 2009 (UTC)

## Wave Science - Incompressibility?

As I understood, the theory says that each particle moves in a circular orbit. I simulated this phenomenon, and as a result, the distance between the particles changes in time. This means that the density of the fluid changes. Isn't this a paradox, while we know that water is incompressible? What is the problem? --Reza M. Namin (talk) 09:07, 11 October 2009 (UTC)

The water-air interface deforms. User A1 (talk) 00:46, 12 October 2009 (UTC)
Sorry, but I don't understand. Can you please explain more?--Reza M. Namin (talk) 12:59, 14 October 2009 (UTC)
The result that orbits are closed has nothing to do with the compressibility, and by the way it is only a lowest order approximation. When you compute particle trajectories with an irrotational wave theory (including Airy theory) you will always find that the orbits are not closed and that there is a drift. This Stokes drift is a second order property of the wave motion (i.e. proprtional to the amplitude squared), just like the wave energy. In fact the Stokes drift is closely related to the wave energy: when summed up over all depths the drift gives a transport that is always equal to E/C where C is the phase velocity.

I do not see the paradox of having a drift without compressibility effect: this is also the case in Couette or Poiseuille flow. What is a bit more surprising is to have a drift that varies over the vertical without having vorticity. This is really because the surface deforms so that the vorticity of the mean Lagrangian motion is different from the Lagrangian mean of the vorticity. Fabrice Ardhuin (talk) 06:05, 4 November 2010 (UTC)

## Oil layer

Why do the wind waves not appear if an oil layer is placed on the water surface? --Reza M. Namin (talk) 13:22, 14 October 2009 (UTC)

There are several effects. First of all the surface tension of the oil film and its viscosity are much larger than those of water. As a result waves dissipate much faster in oil than in water. Even if the oil is a very thin film sitting on top of the water

it does not stretch like the surface of clean water, such that there is a big difference in the velocity of the water and of the oil. This very strong shear also produced a strong dissipation. See e.g. K. H. Christensen, “Transient and steady drift currents in waves damped by surfactants,” Phys. of Fluids, vol. 17, p. 042102, 2005. —Preceding unsigned comment added by 82.253.224.234 (talk) 11:17, 31 January 2010 (UTC)

## GIFs are to large

I just visited this page and it brought my broswer to a stand still for a short time.

The GIFs on this page are ~5MB, that is to large for non-optional page content. —Preceding unsigned comment added by 145.99.220.68 (talk) 20:11, 27 January 2010 (UTC)

Thankyou for bringing this to my attention; I have replaced the images with a static image and a link to the animation. User A1 (talk) 22:22, 27 January 2010 (UTC)

## Possible WP:COPYVIO

This edit introduced copyright-claimed material from Yale-New Haven Teachers' Institute. Hesitating to delete, as some material from outside sources has been "donated" to the page in the past. The outside edit is dated 2006, the WP entry June 2007. Requesting other views, please. --Old Moonraker (talk) 16:13, 2 February 2010 (UTC)

OK, no defenders. Deleting. --Old Moonraker (talk) 08:26, 5 February 2010 (UTC)

## Airy wave theory confusion

Hi, I know it does not belong to this article, but it lies very close to it. In the article airy wave theory, equation 4 in the section about the mathematical formulation of the theory doesn't make any sense to me. It might also be an incorrect equation, but I'm not completely sure. Could someone please check it out and if it's correct explain it to me? You can read what I've written about it on the talk page of the airy wind theory article. Thanks to anyone who can help me understand it! --Kri (talk) 21:17, 15 October 2010 (UTC)

## Breaking height to wavelength ratio

The article states "Individual waves in deep water break when the wave steepness — the ratio of the wave height H to the wavelength λ — exceeds about 0.17, so for H > 0.17 λ." without reference. Other references I've found (e.g., Scripps' website) state that the deep water ratio is about 1/7 (i.e., 0.14), based on observations of wave behavior (so it's apparently not based on rigorous fluid dynamics). This suggests a possible typo or misrecollection (1/7 to 0.17?). Does anyone have a good textbook reference either way? 192.5.27.138 (talk) 16:39, 11 May 2011 (UTC)

The reference is given, ref. 6 (Dean & Dalrymple), after the next line. In random waves, the individual wave height can exceed the maximum height of periodic waves over a horizontal sea bed (about 1/7 of the wave length in deep water). -- Crowsnest (talk) 12:28, 14 May 2011 (UTC)

The first correct estimation of the maximum wave height as a function of the water depth D was performed by Miche (Annales des Ponts et Chaussées, Vol. Tome 114 (1944), pp. 369-406.) using analytical calculations. The result is very well approximated by H/λ = 0.14 tanh (2 π D / λ). This was confirmed by the computer calculation of Dean and Dalrymple (1974), as reported, for example in: Filipot, J.-F., F. Ardhuin, and A. V. Babanin (2010), A unified deep-to-shallow water wave-breaking probability parameterization, J. Geophys. Res., 115, C04022, doi:10.1029/2009JC005448. Ardhuin (talk) 08:36, 16 July 2011 (UTC)

## Trochoidal wave

In 'Seaworthiness', Marchaj says water waves can be described as trochoidal waves. So shouldn't that be mentioned here as well? (Even if it is wrong, since an expert mentions it.) Also see another thread at Talk:Trochoid. DirkvdM (talk) 08:47, 13 October 2011 (UTC)

## Article name

I find the name of the article confusing. It suggests that it's about waves in the wind. Which, indeed, do exist. At least, there are fluctuations in wind (which makes sense since any (relative) movement causes vibrations). 'Ocean surface wave' was too limiting, but then what about 'water surface wave'? That would include other sorts of waves (rogue). Above, 'wind generated wave' has been suggested, which also isn't perfect, but seems less confusing to me. The most descriptive name woud be 'wind generated water surface wave'. A bit of a mouthful, though. :) DirkvdM (talk) 09:04, 13 October 2011 (UTC)

## Wave formation

The info in wave formation is great. However, I'd really like to see it expanded just a bit, to help improve understanding of wave formation in intuitive terms. Currently, it says that all 5 factors cause waves to be higher when the factor is increased. This is correct, but as I recall from "weather for sailors":

• higher wind speed causes wave height to grow faster
• fetch limits wave height

As a consequence, we see the following:

• We can get very big waves with relatively little wind, if the fetch is long and the wind has been steady for a long time.
• With high winds, we can reach the maximum wave height for a given fetch quickly

All other things being equal, waves travel more slowly (with shorter wavelength) in shallower water. That causes them to turn towards shore.

I think observations of this kind would help folks who are intelligent but aren't quite up to interpreting the math given below, which I believe does cover most of these factors, except for fetch and fetch width. No doubt there are mistakes in my observations, but if someone who really understands the subject could include something like this I think it would be very helpful.

Learjeff (talk) 22:21, 21 November 2012 (UTC)

## Edit request, motion of a single drop of water in a wave and why waves are white?

Why is there no explicit answer to why buoyant objects bob (like a bottle) on the waves and don't really move in the direction of the wave as much as you'd expect?

If we followed a single drop of water during a passing wave, we would see it move in a vertical circle, returning to a point near its original position at the wave's end. These vertical circles are more obvious at the surface. As depth increases, their effects slowly decrease until completely disappearing about half a wavelength below the surface.

http://www.onr.navy.mil/Focus/ocean/motion/waves1.htm

I understand that the above websites buoyant object/bottle .gif and description may not be the whole story, as according to the article, Stokes drift prevents the ellipses/circles from being entirely closed, but either way, why is there no mention at all to the motion of bottles/buoyant objects in general, in this article? Is their motion best described as the sum of the surface and subsurface motions due to stokes drift?

Stokes drift in deep water waves, with a wave length of about twice the water depth. Click here for an animation (4.15 MB).
Description (also of the animation):
The red circles are the present positions of massless particles, moving with the flow velocity. The light-blue line gives the path of these particles, and the light-blue circles the particle position after each wave period. The white dots are fluid particles, also followed in time. In the case shown here, the mean Eulerian horizontal velocity below the wave trough is zero.
Observe that the wave period, experienced by a fluid particle near the free surface, is different from the wave period at a fixed horizontal position (as indicated by the light-blue circles). This is due to the Doppler shift.

Secondly why is there no answer in the article to the question of why "whitecaps" are white? AKA How ocean waves turn the water from blue/transparent to white in color? My limited physics knowledge would lead me to conclude it is due to air bubbles being entrained within the water/ the water turning frothy and light scattering due to Mie scattering, but either why, the article should have an explanation for the "white" color of waves. As presently it just assumes everyone knows waves go white but doesn't explain why.

Replies much appreciated!

Test shot Nectar of Operation Castle produced a yield of 1.69 megatons. Note the distinctive near instantaneous double flash, with the second appearing brighter than the sun, and the blast wave slowly, by comparison, spreading out turning the calm ocean water a distinctive frothy white as it arrives.

86.46.191.135 (talk) 01:43, 3 January 2014 (UTC)

Wikipedia is a work in progress, done by volunteers who are not always experts in their subjects, If you see an article which needs improvement, go ahead and improve it to the best of your ability. Content first. Don't worry about formatting, that can be fixed later. That is what we all try to do here. Cheers, • • • Peter (Southwood) (talk): 16:46, 13 January 2017 (UTC)

## Title

Some years ago this was moved from "Ocean surface wave" to "Wind wave". As it stands the former title better covers the article content, I think. Comments? All the best: Rich Farmbrough00:20, 26 April 2014 (UTC).

No. Google scholar gives 2,350 results for "Ocean surface wave" and 34,000 results for "Wind wave". But good to see you back here Rich! --Epipelagic (talk) 05:19, 26 April 2014 (UTC)
And Google scholar gives 40,800 results for "Ocean wave", so with this argument that would be the new title. Much of the content in this article is specific to wind waves, some is general to all surface water waves and there is only a little content about tsunamis, storm surges and tides, so a renaming would require a major rewrite, which i don't think is motivated. To me it would make sense to have a separate article on ocean waves, which would summarize and compare wind waves, tsunamis, storm surges and tides. Ulflund (talk) 15:40, 29 August 2014 (UTC)
Yep. Something to explain the common aspects of all surface gravity waves would be great... even some discussion of tides. I can help if others have the courage to start. Ardhuin (talk) 17:52, 15 September 2014 (UTC)
I too think we should move this back to "Ocean surface wave", per Ulflund. This title is also rather confusing. I will start a move discussion if no one comes up with a valid argument in say, two days. Rehman 00:08, 26 March 2016 (UTC)
Both are valid topics and have a large overlap, but are not the same. • • • Peter (Southwood) (talk): 16:51, 13 January 2017 (UTC)

## Rewrite of section Wave formation

This was appalling. I have rewritten it and hope it is now merely bad. I don't have the references, so can't check the validity of my interpretation of the original text. If anyone passes by with an understanding and knowledge of the theory, please help to fix. • • • Peter (Southwood) (talk): 16:41, 13 January 2017 (UTC)