Claim: the ocean has become more stable and stratified thanks to global warming

From the INSTITUTE OF ATMOSPHERIC PHYSICS, CHINESE ACADEMY OF SCIENCES

The global ocean has become more stratified and stable over the past few decades with global warming. This has major consequences for life in the ocean by reducing nutrients and oxygen, and it greatly affects climate.

Ocean color difference when two water mass meets.
CREDIT Jiang Zhu

A new study, by a group of international researchers from China and U.S., published in Nature Climate Change found that the global ocean has become more layered and resistant to vertical mixing as warming from the surface creates increasing stratification.

Sea water generally forms stratified layers with lighter waters near the surface and denser waters at greater depth, i.e. warmer fresher waters atop colder more saline ones. This stable stratified configuration acts as a barrier to water mixing that impacts the efficiency of vertical exchanges of heat, carbon, oxygen and other constituents. Therefore, the stratification is a central element of Earth’s climate system, and understanding its changes with global warming has great scientific, societal and ecological consequences.

As human-caused greenhouse warming has fundamentally altered oceanic temperature and salinity fields, impacts to stratification are expected but the details have been difficult to discern until now. The main basis for estimating the stratification change is the sparse distribution of ocean observations both horizontally and vertically. Previous quantification of stratification change has been limited to a simple index and has neglected the spatial complexity of ocean density change.

The new study overcomes the key limitations and provides an estimate on ocean stratification for the upper 2000m and also its spatial structures. This study used a carefully evaluated ocean temperature and salinity data (IAP products) which overcomes previous systematic biases associated with sampling. The study also adopted an improved metric of stratification (related to the density gradient over depth), and then provide a true estimate of ocean stratification and its changes.

The new data shows that ocean has become more stratified by 5.3% since 1960 for the upper 2000m. An even stronger ocean stratification increase, as much as 18%, has been observed for the upper 150m.

This observed long-term increasing trend of stratification is mainly caused by stronger ocean warming for upper layers versus the deep oceans (~97%), but salinity changes play an important role locally. This stratification increase reveals a robust human-driven change in the ocean due the long-term temperature and salinity change structures. Therefore, the observed ocean stratification increase is another irrefutable piece of evidence of human-driven global warming.

In the tropics, there is a very strong stratification increase at upper 200m. This indicates a significant change in tropical thermocline depth that is important to the El Nino phenomenon. In the middle and high latitudes, significant increases of ocean stratification appear below 500m, implying an impact on deep ocean stability by climate change.

The increase of ocean stratification feedbacks to climate change. With increased stratification, heat from climate warming cannot penetrate into the deep ocean as readily, which helps to raise the surface temperature. It also reduces the capability of ocean carbon storage, exacerbating the global warming. It prevents the vertical exchanges of nutrients and oxygen, and impacts the food supply of the whole marine ecosystems.

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The paper: https://www.nature.com/articles/s41558-020-00918-2

Abstract

Seawater generally forms stratified layers with lighter waters near the surface and denser waters at greater depth. This stable configuration acts as a barrier to water mixing that impacts the efficiency of vertical exchanges of heat, carbon, oxygen and other constituents. Previous quantification of stratification change has been limited to simple differencing of surface and 200-m depth changes and has neglected the spatial complexity of ocean density change. Here, we quantify changes in ocean stratification down to depths of 2,000 m using the squared buoyancy frequency N2 and newly available ocean temperature/salinity observations. We find that stratification globally has increased by a substantial 5.3% [5.0%, 5.8%] in recent decades (1960–2018) (the confidence interval is 5–95%); a rate of 0.90% per decade. Most of the increase (~71%) occurred in the upper 200 m of the ocean and resulted largely (>90%) from temperature changes, although salinity changes play an important role locally.

62 thoughts on “Claim: the ocean has become more stable and stratified thanks to global warming

    • When all you have is a hammer, everything looks like a nail.

      When you assume that climate change is all due to man, then everything looks like the result of it.

      So, they have identified that the oceans are more stratified. What does this mean in the real world? Is this just a phase it goes through regularly or irregularly? It certainly is not due to human activities as it takes 100s of years to significantly alter oceans and their currents.

  1. Heat cant penetrate water, period. SAGE, Tangaroa experiments. The oceans are incapable of absorbing ‘global warming’,

    This is the usual ‘lets find a childishly simple mechanism, and then say GW makes it worse’. Like with polar bears and ice. Less ice, less food, more die. Turns out to be complete cr@p.

    It is probably more stratified because there are less storm activity, something Lindzen predicted with polar warming.

    Anyway, life will evolve. It always has, it always will.

      • There are some 300 million square kilometers of sea – oceans etc.
        How many samples?
        So – how far apart?

        Auto
        Just askin’, you know.

    • I think you mean to say they can’t heat by absorbing heat from air given water has ~2500 heat capacity of air, would that be fair comment?

      • Heat moves by conduction, convection and radiation from hot to cold objects in this multiverse reflection. The specific heat capacity of the two objects has nothing to do with it. It has recently been found that Planck’s black body radiation rules are sheer nonsense but in the case of warmer air moving over and interacting with a colder ocean that radiative error is negligible so yes warm air will heat a colder ocean.

        • At most it causes evaporation as the partial pressure difference between the H2O in the ocean and in the air changes.

          Try warming water with a hair drier from above….. see how far it gets you.

          • Short wave radiation (light) heats the oceans. Always has. The only role that air temperature plays is controlling how quickly the heat put into the water by the sun can escape to the atmosphere.

        • Evaporation essentially prevents the atmosphere heating the oceans.
          Try boiling a pan of water with a blow lamp on the surface.!!

        • No. Evaporation occurs at constant temperature thus making the Planck Sensitivity Coefficient ZERO This is what happens at the ocean/atmosphere interface.

        • Contrary to most comments, warm air will warm colder water. The big issue is the amount of heat inertia for the lack of a better term. Drop a small sliver of ice in a large cup of coffee. It *will* warm the coffee but probably not enough for you to notice. The wind and ocean is the same thing, Warm wind doesn’t represent enough heat to warm the large sink that is the ocean. In fact, just the opposite happens!

          • Anything warmer than another thing would warm it. The oceans are warmer than the air on average, though, so the flow of energy is towards the air.

    • Of course ‘heat’ can penetrate water, specifically the Sun’s radiation, down several meters below the surface, and GHGs reduce surface radiation losses, not to mention that higher humidity reduces evaporative losses.

  2. Obviously that not picture of ocean stratification.
    I wondered where picture came from {gulf stream??} but didn’t get my answer.
    But did find something related to topic:
    Mythbusting ‘the place where two oceans meet’ in the Gulf of Alaska
    https://www.adn.com/science/article/mythbusting-place-where-two-oceans-meet-gulf-alaska/2013/02/05/
    That was glacier water having more iron in it. But lot reasons change color of oceans and has nothing to with stratification.

    • Looks like Hong Kong, with masses of sewer waste do mped from barges to help make the dainty brown colour. You could smell it as you flew overhead at low altitude. But, right or wrong, what does the photo have to do with the article? Geoff S

  3. post hoc ergo propter hoc.

    Yeah, right ! and we didn’t get nuclear weapons until women were given the vote.

    Piffle.

    • Oh, Ken, it’s a joke. Women got the vote in 1920. We got nukes in the 1940s. Now you know that, so you have to find a different way to grumble.

  4. With increased stratification, heat from climate warming cannot penetrate into the deep ocean as readily

    So first the heat was missing. Then they found it at the bottom of the ocean but couldn’t explain how it got there. Now they’re saying that warming would prevent it from getting there.

    There’s more serious problems with this paper, but that one’s the most fun.

  5. Climate Change “science” has made every possible prediction according to the hypothesis.

    Colder. Warmer.
    Drier, Wetter.
    Oceans more stable. Oceans less stable.
    Less blah,, more blah, blah.
    You get the picture of the scam.

    It’s only after the fact, that the Climate Charlatans point to the winner… as if they”predicted” it, while ignoring the dozens of failed predictions.

      • Poor loy.

        How did they measure the stratification in 1961?

        Its Mickey Mann et al…. OF COURSE its flawed. !! or more likely fraud.

          • Answer they modelled it 🙂

            So they took a set of salinity and temps going back to 1960 and they had the argo bouy data from 2000. So you model the data from 2000-2020 then you hindcast it backwards to 1960 wave your hands and pray to the data gods. There is no way to validate it for at least another 50 years but you get to make stupid untestable claims in the meantime AKA standard Climate Science ™.

      • Theoretical Physics is an accepted field; the people involved generally know that they are guessing.

        Theoretical Climate Entanglement is not a real field of study; the people involved are charlatans, self-deluded, or both.

        One thumb on the scales, one thumb in a completely different place.

        • Theoretical Physics also doesn’t ask you to stop your entire economy based on the guess. Firstly because they aren’t economists and secondly because they would only detail the problem and give a number of solutions. Climate Science is apparently the only field that thinks they supersede every other field and are qualified to give authorative answers about things they know nothing about.

  6. If they developed a new method of measuring stratification, what is their basis for saying it has changed? Would one not have to use the new method for many years to observe changes?

    • My thought too, but then I realized they probably just extrapolated back in time, based on a few years of sporadic data doctored to suit the man-made global warming, which again is a wild guess modified to gain from the popular scare politics.

  7. Here’s the BS part: “As human-caused greenhouse warming has fundamentally altered oceanic temperature..”

    Of course it’s “humand-caused”. Would it be an issue if it was “nature-caused”?

    • And if it is nature caused it would warm the atmosphere and if it warms the atmosphere It’s not AGW and if the surface of the ocean warmed because of natural stratification the CO2 would be released into the atmosphere. Ie they just debunked the entire AGW theory.

  8. ROFLMAO

    three of the authors..

    Kevin E. Trenberth, Michael E. Mann & John P. Abraham

    Farce heaped upon farce.

    We know what these guys and their FANTASY mathematics is like. !

    And data from 1960….. capable of doing what they are pretending. ? !

    These guys are a JOKE. !

  9. I used to see this in the Merchant Navy sailing off the African coast in the 1950s and 1960s. We could be a hundred miles or more off the delta of one of the enormous African rivers and would sail through lanes of muddy water and all sorts of jungle debris.

  10. From the paper–“This uncertainty results from incomplete observational data (discussed further below) and which ocean layers are used. Ocean temperature and salinity observations are somewhat sparse and unevenly distributed in space……. Our observational results thus provide important benchmarks for evaluating climate models used for future projections.” They use the word objective, but claim support for all sorts of negative conclusions from storms to biodiversity. That is diverse expertivity. Anthropometric?

    Look forward to seeing an “objective” mathematical analysis. There are fisheries papers around that this reminds me of, current fad is Boosted Regression Trees. Same negativity, always ignored caveats but pat themselves on the back. As to the first two sentences in the abstract, wow, what a discovery.

    As to the muddy picture, looks like mud.

    • Yes they it’s the usual Climatetards up to the usual crimes against data, but if you say it fast and often enough the MSM tards will push it as well.

  11. Sea water generally forms stratified layers with lighter waters near the surface and denser waters at greater depth, i.e. warmer fresher waters atop colder more saline ones.

    Uh, doesn’t evaporation cause an increase in the salinity of surface waters?

    This stratification increase reveals a robust human-driven change in the ocean due the long-term temperature and salinity change structures.

    An unsupported assertion if ever there was one.

    In the tropics, there is a very strong stratification increase at upper 200m. This indicates a significant change in tropical thermocline depth

    So are they saying the thermocline is deeper or shallower?

  12. There are plenty of examples of waters from different systems looking, different. The Blue and White Nile at Khartoum in Sudan for instance. Or the green and blue seas/oceans at Cape Ringa in northern New Zealand. Climate change?

  13. If they are using a new method, how did they get data from 1960 to make the comparison? Did they use computer models? What is their margin of error? I seriously doubt they know how stable the ocean was ten years ago, let alone 60 years ago. It seems that if nobody has data to prove them wrong, including themselves, the authors can make any claim they want.

  14. “It also reduces the capability of ocean carbon storage, exacerbating the global warming. It prevents the vertical exchanges of nutrients and oxygen, and impacts the food supply of the whole marine ecosystems.”

    So, warmer surface water and stronger stratification means less ocean “acidification”, because less co2 is dissolved. But in reality its not an acidification, its neutralization.

  15. The new study … provides an *estimate* on ocean stratification … This study used a *carefully evaluated* ocean temperature and salinity data … The study also adopted an *improved metric* of stratification … and then provide a true *estimate* of ocean stratification and its changes.

    Colour me deeply cynical!

  16. so you are led to believe that they sampled 2000m of the entire ocean and above? WOWZERS! That’s amazing and incredible, funny how much diesel did they burn while they were sampling the entire ocean? Did they form a grid? What time of year did all of this take place? I’d love to see the research vessel that sampled every water column in that grid across the entire ocean myself.

    El Nino is not new. I wish they would stop using it as a marker for everything. Peruvian fisherman have known about it for as long as they’ve fished in that particular portion of their coast and guess what? That’s way before 1950.

  17. Okay, so the plate boundaries where venting is going on, e.g., the Juan de Fuca plate, don’t count for anything, right?

    And those areas way down deep where the black smokers are, which I brought up a day or so ago, also count for nothing, right? They aren’t particularly rare, either. The oceans are full of them.

    No, it can’t possibly be anything natural, which The They can’t control. It has to be man-made, which is horrendously offensive by its very existence, and provides them with more grants money. What sad, limited lives these people lead.

  18. From the article: “As human-caused greenhouse warming has fundamentally altered oceanic temperature and salinity fields”

    Another unsubstantiated assertion by alarmists.

    There is no evidence that Human-caused CO2 has altered anything to do with the Earth’s atmosphere or oceans.

    The whole of alarmist climate science is based on speculation about CO2. It is fact-free science.

    The basic premise about CO2 and climate change has never been shown to be correct. All alarmists are working on the assumption that the premise is correct, yet there is no evidence showing it is correct.

    The basic foundation of Human-caused Climate Change science has never been established. Building without a foundation will cause all your efforts to come crashing down at some point.

    Building without a foundation is not scientific. It’s anti-science.

  19. Perhaps this is what is causing the warming, a stratification and less vertical turning with the very cold bottom ocean that is 90% of the volume of the ocean. Causing an Atlantification and a Pacification of the Arctic Ocean as the warm waters reach into the northern realms, warming the northern climes and decreasing ice. Then they cycle keeps going and we go into a cooler period sometime in the future.

  20. We are altering the ocean in a couple of major ways. 1. Dissolved silica run-off. This alters the phytoplankton blooms as diatoms, which bloom first in the spring, bloom for longer. This reduces the time for DMS production, meaning less stratocumulus cloud, more warming and stratification.

    2. Light oil* and surfactant spills form smooths with a one molecule layer reducing wave action Less turbulence, more stratification, less mixing with fewer nutrients in the upper light layer, less DMS.

    It would be worth looking at phytoplankton surfactant production — if there’s more of that for some reason then this, too will lead to stratification.

    *Hence the ‘blip’.

    JF
    Mann and Trenberth? Dear, oh dear.

  21. There are some 300 million square kilometers of sea – oceans etc.
    How many samples?
    So – how far apart?

    Auto
    Just askin’, you know.

  22. “Therefore, the observed ocean stratification increase is another irrefutable piece of evidence of human-driven global warming.”
    Really-irrefutable? Nothing else could cause these stratification observations? Not natural warming? Not observational error? Not misinterpretation of data? Not lack of sufficient data? So this study is the missing link. No other research has yet produced proof that warming of earth’s oceans is caused by humans but this one does? I am not convinced. I don’t think there is proof that humans have caused an appreciable increase in CO2 or that increased CO2 has caused any warming so I can’t possibly see how this estimate of changes in stratification cna be considered “irrefutable evidence of human-driven global warming”.

  23. And so these “scientists” are basing their conclusions on a few years of data, the merest blink of an eye in the time frame of the earth as usual.
    The starting hypothesis and immediate question for them is the same as for the rest of the AGW doomsters. “What caused previous climate changes?” “How has the earth reacted in the past during the many, many previous climactic changes that occurred without the excuse of mankind even being there?”
    It seems to me that until they answer these most basic questions the “paper” they are writing on is useful as toilet paper and not much else.

  24. That’s not the effect of rising CO2 forcing, it’s the result of weaker indirect solar forcing driving a warm AMO and increased El Nino conditions, which then reduce low cloud cover. The stratification should be reduced with the next cold AMO phase and increased La Nina.

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