![screenshot_wave_graph[1]](http://wattsupwiththat.files.wordpress.com/2013/09/screenshot_wave_graph1.jpg?quality=83 "Posts by Hannah Hickey")
Waves breaking over sandy beaches are captured in countless tourist photos. But enormous waves breaking deep in the ocean are seldom seen, although they play a crucial role in long-term climate cycles.
A University of Washington study for the first time recorded such a wave breaking in a key bottleneck for circulation in the world’s largest ocean. The study was published online this month in the journal Geophysical Research Letters.
The deep ocean is thought of as dark, cold and still. While this is mostly true, huge waves form between layers of water of different density. These skyscraper-tall waves transport heat, energy, carbon and nutrients around the globe. Where and how they break is important for the planet’s climate.
“Climate models are really sensitive not only to how much turbulence there is in the deep ocean, but to where it is,” said lead author Matthew Alford, an oceanographer in the UW Applied Physics Laboratory. He led the expedition to the Samoan Passage, a narrow channel in the South Pacific Ocean that funnels water flowing from Antarctica.
“The primary importance of understanding deep-ocean turbulence is to get the climate models right on long timescales,” Alford said.
Dense water in Antarctica sinks to the deep Pacific, where it eventually surges through a 25-mile gap in the submarine landscape northeast of Samoa.
“Basically the entire South Pacific flow is blocked by this huge submarine ridge,” Alford said. “The amount of water that’s trying to get northward through this gap is just tremendous – 6 million cubic meters of water per second, or about 35 Amazon Rivers.”
In the 1990s, a major expedition measured these currents through the Samoan Passage. The scientists inferred that a lot of mixing must also happen there, but couldn’t measure it.
In the summer of 2012 the UW team embarked on a seven-week cruise to track the 800-foot-high waves that form atop the flow, 3 miles below the ocean’s surface. Their measurements show these giant waves do break, producing mixing 1,000 to 10,000 times that of the surrounding slow-moving water.
“Oceanographers used to talk about the so-called ‘dark mixing’ problem, where they knew that there should be a certain amount of turbulence in the deep ocean, and yet every time they made a measurement they observed a tenth of that,” Alford said. “We found there’s loads and loads of turbulence in the Samoan Passage, and detailed measurements show it’s due to breaking waves.”
It turns out layers of water flowing over two consecutive ridges form a lee wave, like those in air that passes over mountains. These waves become unstable and turbulent, and break. Thus the deepest water, the densest in the world, mixes with upper layers and disappears.
This mixing helps explain why dense, cold water doesn’t permanently pool at the bottom of the ocean and instead rises as part of a global conveyor-belt circulation pattern.
The Samoan Passage is important because it mixes so much water, but similar processes happen in other places, Alford said. Better knowledge of deep-ocean mixing could help simulate global currents and place instruments to track any changes.
On a lighter note: Could an intrepid surfer ride these killer deep-sea waves?
“It would be really boring,” admitted Alford, who is a surfer. “The waves can take an hour to break, and I think most surfers are not going to wait that long for one wave.”
In fact, even making the measurements was painstaking work. Instruments took 1.5 hours to lower to the seafloor, and the ship traveled at only a half knot, slower than a person walking, during the 30-hour casts. New technology let the scientists measure turbulence directly and make measurements from instruments lowered more than 3 miles off the side of the ship.
The researchers left instruments recording long-term measurements. The team will do another 40-day cruise in January to collect those instruments and map currents flowing through various gaps in the intricate channel.
Co-authors of the paper are James Girton, Gunnar Voet and John Mickett at the UW Applied Physics Lab; Glenn Carter at the University of Hawaii; and Jody Klymak at the University of Victoria. The research was funded by the National Science Foundation.
###
- Visit the Wavechasers website
- Watch the authors conduct research in Samoa
- Read the new research paper
Discover more from Watts Up With That?
Subscribe to get the latest posts sent to your email.
Good paper. Unsurprising result. Doesn’t support the Trenberth missing heat nonsense, which requires heat transport from the surface mixed layer to well below the thermocline. Theese waves are miles below that on the deep seabed.
What is really important about this kind of work is that it falls entirely outside the “radiation-only” model of global warming that has guided Alarmists for decades and that seduced Trenberth at least until his “travesty” statement. This is empirical research of the deep oceans and it will stand or fall on its success in describing the natural regularities that constitute these deep oceans waves and similar ocean mixing phenomena.
Any heat that is found to be mixed into the deep oceans is heat that must be subtracted from the radiation budget of the sun-earth-ghg nexus. How long any such heat can remain sequestered in the deep oceans is a question that will be studied for decades and maybe centuries. (Empiricists are necessarily humble.)
My whole set of complaints against mainstream climate scientists is that in the past they refused to consider that this kind of research was necessary to complete their science. Instead, they trumpeted their certainty about conclusions inferred from an incomplete science where empirical work was treated like an unwelcome guest.
Caleb says:
September 11, 2013 at 2:26 am
Excellent post. Other people who are posting seem to want to treat this article as a failure. If the article is treated as a ready-made solution for something then it is a failure. But if it is treated as the beginning of empirical research that will takes decades to complete then it is very interesting. In any case, we should celebrate the fact that Alarmists are leaving the “radiation-only” theory for actual investigation of reality.
Greg Goodman says..
“El Nino is decribed as 3 to 5 year pseudo cycles. Modulate 4.43 years with something like 28 years and you get just that. ”
Interesting. Greg, could you or someone here explain the root of the “28 year” period to me?
Gary Pearse says:
September 11, 2013 at 4:50 am
Superb post! Especially on empiricism or experimentation. As regards Chaos Theory, why is it that everyone in the AGW debate will agree that climate is chaotic but no one actually applies Chaos Theory? One wants to say to them: “The existence of attractors can be inferred and predicted; hello, is anyone home.”
Jeff I agree. It was off-topic, jarring and completely unnecessary. These injections are usually an attempt to elicit emotion, often done to massage your own need. The truth is, most adults have naturally intertwined this event into their lives, which happens with most tragedies over time, but hardly forgetting it. Poking is unnecessary. Lets stick to the deep ocean waves and fluid dynamics.
Immense ocean whirlpools that have never before been observed….waves taller than skyscrapers….is it just me, or are the CAGW community really reaching hard to justify this “the heat is really, really missing in the deep ocean!” line?
I’d love to be the fly on the wall at the IPCC regarding the upcoming AR5. Government officials worldwide are becoming very impatient with all of this “Wait, any day, the Arctic sea ice will be in a death spiral!” nonsense. It’s kind of fun to watch, actually….
And, thanks for remembering 9/11, don’t forget that the US and many allies are still nations at war…please hold our soldiers and first-reponders in your thoughts today.
Three quotes show that climate models are no good by Matthew Alford. If you have a process, climate models here, really sensitive to a force and its location you know very little about. If the climate models get the data input about the force we know very little about from people that still know very little about that force. Then it’s no wonder the climate models can’t accurately forecast the future climate.
“Climate models are really sensitive not only to how much turbulence there is in the deep ocean, but to where it is,” said lead author Matthew Alford,
“The primary importance of understanding deep-ocean turbulence is to get the climate models right on long timescales,” Alford said.
The Samoan Passage is important because it mixes so much water, but similar processes happen in other places, Alford said. Better knowledge of deep-ocean mixing could help simulate global currents and place instruments to track any changes.
Bottom line for him: Better give me more money to study this. After all he is going to have to find and measure all of the locations in the ocean where this deep mixing is taking place before the climate models can work correctly.
How did that skyscraper get down there? Atlantis? The truth is out there.
if they could just trace the course of these “35 Amazon rivers” they would have done something worthwhile.
The average of these “tides” and waves is….. zero. There is more heat (energy) transported in 1 second via the sub-surface conveyors than anything happening at the spot level of these turbulence points move my lifetime. That is grand hyperbole of course, but this desperate need to create sources of missing heat is getting absurd. How the hell did the heat get there to be mixed without being noticed? These geniuses got an answer to that?
“The primary importance of understanding deep-ocean turbulence is to get the climate models right on long timescales,” Alford said.
I thought that the science was settled and climatologists had complete faith in their models.
Back in 2008 there was discussions about newly discovered volcanos on the ocean floor beneath the Arctic ice cap. When it was suggested that underwater volcanic activity could result in melting of Arctic ice or in atmospheric warming, it was dismissed by the global warming alarmists. The reason given was underwater volcanic activity, while unseen, was part of the long term, steady state geothermal background flux and was therefore already included in the models.
Here we have unseen, long term, steady state mixing of water in the deep ocean. This discovery however may hold the key to how the oceans are hiding the postulated missing heat and therefore must be taken into account by the models.
Does it ever impress anyone how climate science tends to have a bias in one direction?
In Feb/Mar 1961, I was on a ship in the middle of the Pacific Ocean that got hit by a tidal wave. The wave was stirred up by an underwater earthquake, I’m thinking somewhere off Alaska. It evidently went miles up some rivers when it struck Australia, and did a lot of damage.
The Ship skipper, said he would sound the ships horn just before the wave hit us, so we could all hide in some safe place.
I did like everyone else, and hid by one of the ship’s rails looking out over the ocean to the north to see my fate coming.
Then the horn sounded, and this monster wave hit us at about 400 miles per hour, if I remember correctly.
Supposedly the wave height was a foot or two and the wavelength was many miles long.
I musta blinked; didn’t see a darn thing; nor did anyone else.
So bottom line: What is the wavelength of these 800 foot high waves that they see out there all the time breaking all over the place ?
Yes; I know; both the ship, and the Pacific ocean, got hit by that tidal; wave.
So sue me !
“”””””……John Day says:
September 11, 2013 at 5:26 am
@joshv
>Water is quite conductive to heat.
Compared to what? Water is less conductive thermally than concrete or glass …
Glass,ordinary 0.8
Concrete 0.8
Water at 20° C 0.6
… and way less conductive than diamonds, the most thermally conductive substance known (thus explaining the nickname ‘ice’ for diamonds)
Diamond 1000
(units: watts per meter-Kelvin)…….””””””
More apt than you realize. That high thermal conductivity number for diamond is not a good number for room or ordinary climatic Temperatures.
In fact type IIA diamond, (the high conductivity type) has its highest thermal conductivity, at around 100 Kelvins. So the “ice” label is appropriate.
And of course the “ice” label refers to the fact that when you touch a diamond (of some size), it does in fact conduct heat away from your finger so you think it is cold.
izen says:
September 11, 2013 at 3:19 am
/////////////////
I consider that you are over simplifying matters.
Assuming that there truly has been some sea level rise, what about plate tectonic displacement? Are there any measurements of this? I do not know whether it is positive or negative but it almost certain to have an impact on sea levels.
At subduction zones, it is conceivable that the the subducting plate pushes the over lying plate upwards and the net effect of this is a positive displacement of 1 to 3 mm per year. Likewise Atols displace sea wateras they are formed. We often do not know about these until the break surface.
Incidentally, I recall seein a picture of the sea bed off the coast of japan after the recent tsunami. I cannot recall the details precisely but I seem to recall that there was a vertical cliff rising upwards from the sea bed to a height of some 40 to 60 metres and extending for may be about 200 km. A lot of sea was displaced in that example and even Japan itself was moved by about 4 to 6 metres.
I am fairly convinced that we do not know the detail of all processes that may lead to sea level rise.
Greg Goodman says:
September 11, 2013 at 4:04 am
tty “Been there, done that. This technique was used by german U-boats transiting Gibraltar Sound in WW 2.”
Wouldn’t that be gliding out on the tide rather than surfing the thermocline?
No, gliding out “surfing” on the denser, saltier return current from the Mediterranean..
Greg Goodman @ur momisugly September 11, 2013 at 4:04 am
This is what they were riding “The Meddy”:-
The following link to the Virtual Seismic Atlas shows the seismic response of the warm dense Mediterranean Bottom Water as it exits west through the Gibraltar Strait and flows beneath the colder surface water of the open Atlantic.
Meddy image GOLR012.
Author: Richard Hobbs
“In the summer of 2012 the UW team embarked on a seven-week cruise to track the 800-foot-high waves that form atop the flow, 3 miles below the ocean’s surface.”
Somebody please explain to me how these 800 foot high waves three miles below the surface aren’t visible at the surface.
I would imagine that the pressure from above keeps these large waves from transporting their height to the surface and instead create a vacuum behind them where the next layer fills in. Fill a deep clear container with a watery sparkly colored substance that only slightly creates more viscosity than plain water and stir with a spoon. You will see how the substance curls and forms waves deep at the bottom that are not necessarily duplicated on top. Deep ocean turbulance will do the same thing. But I would grant that the speed of those currents are much less than the speed of surface currents.
This is a hump day hilarity. First of all, the cut-to-the-chase nature of the original assertion:
“These skyscraper-tall waves transport heat, energy, carbon and nutrients around the globe. Where and how they break is important for the planet’s climate.”
Just like that. Race to a broad conclusion. Hold on a minute. Waves don’t transport very much more than kinetic energy. Individual particles of ‘stuff’ (I’ll point to the “CARBON”) basically rotate in place as the energy passes by. The ‘stuff’, Mr. Alford, will not be transported. Best get your understanding of fluid dynamics under control before you carry on with this line of ‘reasoning’. “Turbulence” on the other hand, is from currents interacting with obstructions, and yes, these currents transport ‘stuff’. The turbulence will certainly mix stuff.
Then there’s all the bandwagon jumping, like Izen above, who ‘distills’ a thermal origin for sea level rise because ice and some speculative aquifers (wow!) can’t account for it. Seems simple enough. A direct parallel to those who distill an anthropogenic signal from a temperature curve once the Ninos & Ninas are subtracted out. A naive oversimplification, by any measure.
The ensuing debate and thinly disguised snark above is laughable….because the paper’s basic premise (and poorly disguised agenda) is flawed at the get-go.
I read somewhere that ocean surface waves, are limited in height to something like 198 feet or something like that. Can’t remember what the nature of the physical limitation was. It was much discussed at the time of “The Perfect Storm” incident.
But deep ocean waves of 800 feet amplitude are nothing. I’ve seen waves in the rocks, that are much taller than that; some of them over 8,000 meters.
Cowabunga! Deep sea surfing!
Theo Goodwin said @ur momisugly September 11, 2013 at 7:58 am
Excellent point!
Again I ask, how come these 800 foot high waves are not visible on the surface? Water is almost in-compressible, therefore there has to be some displacement upwards as the wave progresses. Or are we talking about some other kind of wave?,