The Role of ‘Ocean Upwelling’ and ‘The Deep Ocean’ in the Glacial Cycles

Guest Post by Wim Röst


Glacial cycles show a gradual diminishing temperature during the slide into the glacial period, but a steep increase of temperature at the start of an interglacial period. As argued here, both ‘ocean upwelling’* and the temperature of the deep ocean might play an important role.


The temperature profiles from interglacial to glacial and the one back into an interglacial is are very unequal. After a short and steep rise of temperatures into the interglacial, there is a much slower and stepwise fall of global temperatures lasting some 100,000 years. It is interesting to consider the role of the oceans in this process. Ocean upwelling and deep-sea absolute temperatures may play important roles.

The unequal temperature profile of a full glacial cycle

As figure 1 shows, after the rapid rise into an interglacial there is a long cooling period. So, how do we explain the following?

  1. The rapid rise of temperatures at the start of an Interglacial
  2. The more gradual / stepwise cooling to the lowest temperatures of the glacial cycle

Figure 1: 400,000-year δ18O

temperatures from the Vostok ice core

Thick blue lines are added. Source for the original

For the rapid rise into an interglacial, some possible explanations include the role of obliquity, insolation, albedo and ‘dust.’ All are already well described. The role of the deep sea and the role of ocean ‘upwelling’ are (as far as I know) not mentioned as a main factor. Which is surprising, as both forces are impressive in their potential effects.

The role of ocean upwelling

Upwelling is a massive force. One million cubic kilometres of water yearly rise from the deep ocean to the surface layer. A one-year halving of this upwelling makes sea surface temperatures, world-wide, rise nearly a tenth of a degree (0.09 °C). This is a huge increase. Diminishing wind diminishes upwelling. And very important: wind is quite variable.

Theoretically it is possible that at the deepest point of a glacial a weather pattern develops that diminishes wind, resulting in less upwelling and/or less mixing. As a result, the warm surface layer would rise quickly in temperature, strongly enhancing the ice melt, decreasing the albedo and so on. This could result in an interglacial.

During the interglacial the pattern of ‘less wind / less upwelling’ could have continued and the interglacial could have stayed warm for a while, at least in some cases. As figure 1 shows, some interglacials only last for a short time, others continue for a longer period. Less wind, less upwelling and mixing could have played an important role in the time an interglacial exists. More wind will activate the huge cooling potential of the deep oceans. This might start the definite cooling process of the surface of the oceans, leading to the next glacial.

The role of the deep seas

Our deep seas are ice cold. Of the total volume of the oceans, 95% have a temperature of less than 5°C. The deepest and coldest waters are near zero degree Celsius. With nearly 1.3 billion cubic kilometres of cold water, the oceans have an apparently endless cooling potential. The variable factor in upwelling and mixing is ‘wind’. Uncontrollable by man.

As argued above, there could be an important role for ‘upwelling’ in the explanation of the rapid rise into an interglacial. But what could the role of the ocean be in the cooling down into a deep glacial period?

First of all, during our current interglacial (MIS 1) the temperature of our deep ocean has risen. A rise that seems to be small, but nevertheless considerable, given the enormous mass and heat capacity of the water involved. The deep ocean temperatures, during the Holocene, have risen around two degrees Celsius (see Figure 2).

Figure 2: Deep Sea temperatures in the last 200,000 years

Source Hansen, et al., 2013.

A rise of the deep-sea temperatures of two degrees Celsius means that during the interglacial all upwelling water is two degrees warmer than during the end of the glacial period. The surface layer of the oceans only contains 72.4 million cubic kilometres of relatively warm water. Yearly one million cubic kilometres of the surface layer is ‘refreshed’ with less cold water, this means that the surface layer soon became two degrees Celsius warmer than the surface layer was during the colder glacial upwelling. This is only because of the difference in the temperature of the upwelling water.

The warmer surface layer deep ocean is one of the reasons that the Holocene can last some time. Even as other ‘interglacial promoting factors’ diminish. The cooling down of the deep sea will take time due to the enormous heat content and capacity of the oceans. There will be a big delay. Upwelling waters therefore will only slowly show lower temperatures, affecting the temperature of the surface layer more gradually.

The enormous heat content of the deep ocean is a massive potential cooling factor as well as a massive potential warming, depending on the actual temperature of the deep seas and the average surface temperatures.

At the start of a new glacial the cooling deep oceans cool the surface but slowly because the heat capacity of the oceans is almost a thousand times higher than the atmosphere’s heat capacity and expelling that much heat takes a long time. But, in the case of warming at the start of an interglacial, only the surface layer – no more than 5% of the ocean volume – must be warmed. Therefore, warming can be quick.

The fast rise of surface temperatures at the start of an interglacial suggests that diminished upwelling did play a role.


Upwelling can play a very important role in creating interglacials. A changing weather pattern resulting in less wind results in less upwelling. Since only the thin surface layer of the oceans must be warmed, a diminished inflow of cooling deep water will have huge warming effects on the surface layer.

The observed warming of the deep sea during the Holocene results in a warmer surface layer. The starting temperature of the upwelling water is two degrees higher and raises the final temperature of the surface layer by two degrees.

Because cooling the remaining 95% of the ocean water takes a long time, this (stepwise) cooling during the glacial period will take a very long period.

With regards to commenting: please adhere to the rules known for this site: quote and react, no personal attacks.

In commenting: please remind you are on an international website: for foreigners, it is difficult to understand abbreviations. Foreigners only understand words and (within the context) easy to guess abbreviations like ’60N’ or ‘SH’.

About the author: Wim Röst studied human geography in Utrecht, the Netherlands. The above is his personal view. He is not connected to firms or foundations nor is he funded by government(s).

Andy May was so kind to read the original text and improve the English where necessary. Thanks Andy!

* For more info about (the effect of) cold ocean upwelling, see my earlier posts here and here.

156 thoughts on “The Role of ‘Ocean Upwelling’ and ‘The Deep Ocean’ in the Glacial Cycles

    • CO2 outgassing from warming ocean surface could be much more significant when atm CO2 is around 150 ppmv than it is now. This would feed further warming : a “tipping point” chain reaction. Like all such +ve f/b mechanisms they are ultimately bounded by stronger negative f/b or else they end up destroying the system.
      Since we are still here and Earth’s climate has been around for a while, it is clear that the diminishing GHE of CO2 gets over powered by the Planck feedback which is non-linear T^4 and negative.

    • Greg – No. You can see that it’s not, by looking at the cooling phase. In this phase, temperatures decrease while CO2 concentrations are higher than they were at the same (rising) temperature during the warming phase. CO2 could not have been driving temperature up during the warming phase – if it had been then it would have driven the temperature back up during the cooling phase.
      Something other than CO2 is doing all the driving of temperature.

  1. One cause of the steep rise could be positive feedback from released CO2.
    CO2 outgassing from warming ocean surface could be much more significant when atm CO2 is around 150 ppmv than it is now. This would feed further warming : a “tipping point” chain reaction. Like all such +ve f/b mechanisms they are ultimately bounded by stronger negative f/b or else they end up destroying the system.
    Since we are still here and Earth’s climate has been around for a while, it is clear that the diminishing GHE of CO2 gets over powered by the Planck feedback which is non-linear T^4 and negative.

    • Other causes for the steep rise in temperature at the start of an interglacial, other than internal ocean dynamics and the interplay between the atmospheric system (wind) and the oceans are not excluded here. But it is strange that the huge forces of the [deep] ocean so far hardly got any attention.

      • You are absolutely right that the biggest cold storage on Earth -the deep oceans- is totally under studied. I blame it on the present single minded man made atmospheric CO2 fad. That’s why I started writing climate science with lower case initials.

      • Wim- Thanks for an interesting and sensible article. The role of the ocean is so important to climate over all timescales. Anyone who doubts that should spend a night in a desert.

    • positive feedback from released CO2.
      this doesn’t fit the evidence. ice ages end when CO2 is low, and they start when CO2 is high. the opposite of what you are suggesting.

      • No, you are not understanding positive feedback. It is a feedback not an initial cause. A classic example of +ve f/b is a traditional light switch with a spring inside. The initial movement is a finger on the rocker. At a certain point in the movement a spring acts to push it in the same direction and it snaps across. The movement is limited by the casing which provides a stronger, mechanical negative f/b to the continued movement.
        The presence of a positive f/b is typical of a system snapping from one pseudo stable state to another one.
        It is precisely the fact that CO2 is low which means the change in GHE is stronger than now.
        I was not suggesting that the CO2 was the cause or the trigger of the change.

      • Greg, if the CO2 and methane is a positive feedback, how does it start warming? Unicorns?
        I recall reading some alarmist tract, several in fact, claiming that water vapour was ‘only an feedback’, that it had no role in warming on its own.
        This is the sort of BS that weakens the whole CAGW meme: that water vapour has no GHG effect unless accompanied by CO2. That is as dumb as the claim that natural warming ceased in 1975 when AG warming took over.
        The meme that CO2 feedback driven by a warming climate is responsible for pulling us out of an ice age is silly. First, CO2 doesn’t have anything like the warming power of H2O vapour, and second, methane is nearly immaterial as a forcing source. There is hardly any in the first place.
        This is a water planet and the climate is dominated by whatever happens in the oceans. Water vapour and ocean temps. Welcome to Earth.

    • Fred is right
      There is no need whatsoever (scientifically, rather than politically) to posit CO2 as a feedback in rapid deglaciation. Albedo is a much more credible driver.
      CO2 really is the spare prick at the wedding. It wants to be needed but is not, at all.

      • There is no evidence in our time that CO2 concentration means anything to global temperature, and water vapour is probably just about evenly divided between being a warming gas and being the conduit of convective cooling.
        Only the blind obedience of the AGW necromancers to the power of their magic molecule that prevents them from seeing any negative feedbacks.
        AHHHH! Negative feedbacks!!! Look away!! Look away!!

    • Greg
      There is only one problem with the CO2 increase causing warming theory.
      CO2 DENSITY is lower during the warming phase. PPM is not density

  2. Glad to see wind considered in the ocean-atmosphere system in this piece. When I feel like exhausting myself by interfacing with a true believer, I ask them the following questions to get a bead on their level of understanding and get us away from the temperature is both accurately measurable and average-able and can stand in comfortably to represent total energy in the system insanity that passes as knowledge in most circles:
    (a) during the period of presumptive “global warming” that started in the mid-1800s, what has “average” global wind speed been? (This is unknowable, and unanswerable, btw.)
    (b) during the period of presumptive “global warming,” what has the aggregate speed of surface currents been on the world ocean?
    (c) during the period of presumptive “global warming,” what has the aggregate vector of surface water been on the world ocean, towards the north or towards the south, or neither?
    (d) during the period of presumptive “global warming,” what has relative humidity been, globally, on average?
    (e) global cloud cover over same period
    (f) global precipitation over same period
    (g) annual number of lightning strikes globally over same period
    Of course, true believers are generally both angry and dismissive by the time I’m through with (a). And, while (a) through (g) is a paltry list of forms of energy in the ocean-atmosphere system, it sure would be nice to have all of that measured and compared to start to be able to have a meaningful conversation. But who likes those?

  3. In commenting: please remind you are on an international website: for foreigners, it is difficult to understand abbreviations. Foreigners only understand words and (within the context) easy to guess abbreviations like ’60N’ or ‘SH’.

    Acronyms and jargon aren’t readily understood by all native speakers either.

    • Jargon is basically OK, but slang and references to American culture are much more difficult. What movie? What car-make? How do you recycle? What do you eat for dinner, when, and with whom? What do you think about Denmark? I often realize I have a pretty vague knowledge on everyday things. My car is a little bit larger than Anthony’s, with manual gear. I love it. It’s a cheap but reliable old friend. My local supermarket (less than half a mile away) is a very small shop with only a few thousand different products. It does not sell alcohol stronger than 4.7%. There are no cigarette commercials anywhere. Smoking is prohibited pretty much inside and many places outside, like at school yard and daycare. Children take a bus to home, or walk, or ride a bicycle. Most live within a mile or two from the school. Wind speed is given in metres/second. A warm summer day is 25C, or 30 at worst. A cold winter day is -10C, or -25 at worst. Dec 24th is a big day. What’s thanksgiving? Halloween? Yeah, they’re marketing it is lot. Midsummer? Yes, big deal. Gotta drown. Preferrably not while swimming in open lake water at 22C, but beer. Many people hunt, but carrying a gun unpacked at a “public” place is a crime with a serious outcome (you loose your guns and rights to own a gun). Policemen (officer sounds bad – army has officers) usually do not touch their guns. Armed 3rd party violence is rare. Shooting while doing a robbery is considered ill-adviced. There’s not much point doing a robbery when you can just walk to the city welfare office and get you drug/booze money. The state gets the booze money mostly back, because taxation is so high with booze.
      There are a huge number of differences in everyday life, which are not actually not so much a big deal as such, but when people expect they’re given, it can be a pain to understand. On the other hand, this site contains lots of talk on everyday phenomena and is instructive to a foreigner because of that.

      • On the other hand, this site contains lots of talk on everyday phenomena and is instructive to a foreigner because of that.

        This an International site! Climate Foreigner?

      • Hugs, I will try to answer all of your questions, since no one else did:
        Movie: Blade Runner
        Car-make: 16-25-Mustang (convertible); 26-38 Cadillac; 38-50 Toyota; 50+ Audi (Full circle, Yay…convertible again)
        How to recycle: Drag it to the curb the night before pickup
        What for dinner: Steak, New York Strip. When hungry. With whoever is around.
        What think about Denmark: I do not think about Denmark. (Ok, when I do I think I have a spare bedroom if anyone wants out…send pic)
        I swim every day in my pool. It is hot and rains in Summer. not so hot and not so much rain the rest of the time. Always blue blue sky and whitest white clouds. Near ground all is green and greener. Yesterday I picked about 50 mangos of my mango tree, but most days i just let the squirrels and birds and raccoons eat them. I have bananas and pineapples and lychees, and tangerines and lemons and limes and navel oranges and temple oranges growing, and coconuts not bearing fruit yet.
        Chemist cabinet maker mechanic detective electrician nurseryman, I can make fix grow or build anything.
        I have left my front door wide open several times while away at work in the past year, and also my garage door several times, and a few times at night. No one noticed.
        I have a hundred huge flowering plants in every raucous color scattered about my driveway and pool area, and every sort of unusual and interesting plant and tree I find or see…I buy. I also pick up seeds from under trees or pick them off the branches. I buy $1 tiny plants that are now as big as a car or taller than my house, and sometimes pick up cut branches from trash piles and stick them in soil when i get home. Everything grows like crazy.
        Last October until May my air conditioner was broke so I slept with the French doors out to the patio/pool area open all night every night. In May one night it was hot so I went up into the attic and fixed it… had never took one apart before (it was just a melted wire and a bad breaker).
        Dogs are fun but messy and they need constant attention so I have cats.
        Life is good, but way too short.

  4. Probably just takes the oceans longer to cool down….
    I’ve more interested in why temps didn’t go up as high this time…and more or less flat lined, measuring error maybe

    • Latitude,
      “…why temps didn’t go up as high this time…”
      It seems to have something to do with the relative phases of the orbital and axial influences. In the prior interglacial, all of the orbital and axial influences lined up to have their maximum positive effect on the temperature within a narrow window of time. In the current interglacial, the peak influences from each are spread out over a much longer period and the peak orbital obliquity is somewhat less making this interglacial cooler and longer than the last one.

    • “upwelling is also important for short term phenomena such as El Nino, La Nina, etc”
      WR: Indeed, it surely is. The lack of cold upwelling during an El Nino (because the upwelling inducing Easterlies diminished) is a factor that enhances the total warming effect visible in the Pacific. The surface lacks the input of the cold deep sea water and therefore the surface of the Pacific gets a higher temperature than without this factor.
      El Nina – characterized by strong Easterlies and a lot of cold upwelling – shows the reverse effect on Pacific surface temperatures: cooling.

      • IMO the up-welling is long term tidal variations on the top of the thermocline. The collapse of the trade winds is a positive feedback which causes the system to snap from one state to the other. The official explanation that El Nino “causes itself” is an excuse for not having understood the root cause effect which triggers El Nino events.
        The dominant surface response is to the 12h lunar forcing and to a lesser extent the 14 day neap/spring tides.. If you look at the density difference between the air and sea compared to the warm mixed layer and cooler, more saline deeper waters it is about 1000 times more.
        This implies that the thermocline will resonate with periods about a 1000 times longer than the surface tides.
        The means the thermocline will resonate with forcing of the order of 1.5 years and to a lesser extent of 20 years.

      • There is a lunar cycle at 18 and 18.6 years. Check out the interval between that last two “!super El Ninos”.

  5. My comment on those cycles is that the rise in temperature when an interglacial start is caused by some accumulation of dust happening during storms in the colder periods. All the ice and snow has become darker with dust. This could explain how fast the world warms. The cooling period occurs after some reduction of the insolation caused by Milankovitch curves. This reduction of insolation requires some time to act, for the surface of the oceans has a great capacity to store energy. But as the planet starts to cool, the snow near the poles, mostly on the higher latitudes of the NH. The increase in snow increase the albedo of the earth and this causes less warming. It is a negative loop because of the increasing albedo. Below some threshold of temperature a process of desertification starts, and also severe storms of dust. The dust reduces the insolation forming like an umbrella that reduces the amount of sunlight that arrives to the surface. After some15,000 thousand years of dust storms, more or less constant, it can start a process of rising temperatures that do not last long. Why? because the heating of the dirt snow melts where the snow is not deep. Most of the snow on latitudes over 45 or 50 degrees, melt and reduces the albedo a little bit. But new amounts of water vapor make it snow again, starting a new process of increasing the albedo. Then, a colling follows. And more dust storms. It is when the the ice and snow are really darker by the dust, then a new interglacial period starts in combination with a higher rate of insolation due to a Milankovitch curve. But a high insolation curve produces not any effect when the clouds of dust are very dense.

    • That would imply that the soot from burning coal is a bigger anthropogenic effect leading to warming.

  6. According to all I have read, glacial maxima are stormy, not calm. Why should there be a sudden lull? And furthermore: deglaciation is comparatively quick but it still takes several thousand years. What would sustain the lull for that length of time?

    • “Why should there be a sudden lull?”
      WR: Good question. What is happening at the end of the LGM is that orbital changes do change the insolation on 65N. Javier’s Nature Unbound series explain the role ‘orbit’ plays. My guess is, that as a result of these orbital changes, there are zonal changes in wind patterns that diminish cold upwelling. Might be a diminishing wind, but it also (!) can be a change in wind direction on upwelling sensitive places. The wind direction plays an important role: not every wind direction causes upwelling on upwelling sensitive places. A regional change in cold/warm areas induces other high pressure – low pressure patterns and so other wind directions.

      • Thanks for your reply, Wim.
        Your explanation sounds plausible. However, note that maxima of insolation at 65N occur much more frequently (approximately once in 22,000 years) than deglaciations do.

      • Michael: “However, note that maxima of insolation at 65N occur much more frequently (approximately once in 22,000 years) than deglaciations do.”
        WR. Yep. In a following post I will try to reveal the cause for this. Oceans will play the main role.

      • I believe that at least where I live in the Northern N.A. plains, the winds in the last few months have been much stronger. This reminds me of the 1960’s and 1970’s and I maintain that the wind has not blown as consistently or strongly since the late 1970’s. Is it just coincidence that we have had a period of warmth since then? Winds are back, it’s cooling down. CO2 GHE is a load of baloney. The Earth as a heat enging has seen many more intense changes and shrugged them off for billions of years. Just career making ctastrophism from small, small minds!

  7. if one watches some graphs about the dust and temperatures for Greenland during the recent glacial period,
    one can see a fine correlation between dust and temperature in the ice cores. You can see that as soon as the dust calms or subsides the temperatures rise.
    I cannot copy and past the graphic. If someone can tell me, the next time I would be able to past a graphic here.

    • “If someone can tell me, the next time I would be able to past a graphic here.”
      WR: If I put the link on a new line, most times a figure shows up

    • Leopoldo, to paste a graphic you need to copy the link of the graphic and then control-v into the comment. You can’t paste the graphic itself.

  8. My current thinking for the rapid rise in temps was change in circulation: As Antarctica bridged to South America it changed the circulation of water in the top layers and had more water from the tropics sending water north which add much more water vapour to the atmosphere which rapidly changed the heat in/out of the atmosphere. Still working on the why it goes down over time besides the wobble, have some preliminary ideas but hasn’t been hashed out solidly enough.

    • Perhaps it helps to think in vertical circulation instead of horizontal circulation.
      Horizontal circulations don’t change easily and quickly. But for example upwelling patterns change even every season. Which shows the sensitive reaction of upwelling on weather patterns and on orbital changes.

      • “Horizontal circulations don’t change easily and quickly. ”
        Yes it does. Tides are primarily horizontal movement of water , despite out perception of measuring vertical differences.
        Tides displace large amounts of surface water , very rapidly.

      • Perhaps figuring in the transition of density as water warms ( 39F being the greatest density for fresh water, don’t know about sea water). Could it be that the oceans settle to a maximum high density state where the small amount of differential during a cold period is not enough to cause turnover? Not sure how that state would change as it warms but the oceans are a heat engine similar to the atmosphere. More energy speeds it up.

      • John Harmsworth: “Perhaps figuring in the transition of density as water warms ( 39F being the greatest density for fresh water, don’t know about sea water”
        WR: The highest density of seawater is not like fresh water at a temperature of + 4 °C. It is very different: seawater reaches its highest density at around – 1,8 °C. Besides that, salinity plays an important role in the ‘sinking or not sinking’ of seawater. More about that later.
        John Harmsworth: “Not sure how that state would change as it warms but the oceans are a heat engine similar to the atmosphere. More energy speeds it up.”
        WR: Oceans are a heat engine, but, less understood, oceans are also A COOLING ENGINE. The lack of thermal energy in our present deep oceans make that the oceans have an important role in cooling the Earth. More about this later.

    • Mydrrin
      That warm water does not have to reach the poles to affect ice, the atmosphere carries the heat. 2007, 2012 and to a lesser extent 2016 prove that. 2016 had a lower ice thickness so it got more bang for less themal transport input.
      This year the Arctic is still fragile to sea ice loss primarily due to low base.

      • Ozonebust, you are right that most of the energy is transported poleward by air movements. But, in ice melting, transport of warm water plays an important role. Because of its high heat content, slightly warmer water is able to melt much more sea ice. That is exactly what is happening in the Arctic, perhaps I will write later about that. Have a look at the following graph:
        (perhaps you must click on the graph to see the actual situation)
        What is shown, is that the average temperature in the melting season (now) is already months below normal, which is the green line. And still there is a huge ice loss. The reason is that in the nineties and in the 2000’s ‘warm water pulses’ putted enormous quantities of Atlantic water below the cold polar surface layer. That warmer water is not + 2 °C but + 3 °C. Just one degree more, but with a huge melting effect on the ice above.
        If you want to read more about these warm water pulses, have a look at this article: Igor V. Polyakov et al. Greater role for Atlantic inflows on sea-ice loss in the Eurasian Basin of the Arctic Ocean, Science (2017). DOI: 10.1126/science.aai8204.

      • Thanks for the link.
        Understand the sea temperature rise. That will soften, wind does the rest. Sea ice area response to wind is daily, ocean reduction is slower.
        If the wind reduces the sea ice loss reduces, even on warmer water. Warmer water is an aid not the controller.
        Looking forward to your next post

  9. the steep rise and slow fall in temperatures is the key to understanding climate cycles. you need something that raises temperatures in a hurry, which requires a large “warm-pool” to draw from. up-welling unfortunately works in the opposite direction. it is large “cold pool”.
    there are only two warm pools available. either the sun or the interior of the earth. the earth’s crust is extremely think in scale. much thinner than the skin of an apple. orbital mechanics and sea floor spreading could regularly release heat from the earth’s core into the deep oceans, which would provide the warm pulse to end the ice age. This would slowly cool off over tens of thousands of years, in time for the next warm pulse.
    keep in mind that the earth;s oceans do not end at the sea floor. they extend into the earth until the each the point where water turns to steam. it is this layer of steam that keeps earths oceans on the surface. otherwise they would have long ago sunk into the crust and disappeared from the surface. as such, the deep ocean heating may be occurring below the floor of the ocean basins.

    • Ferdberple, Don’t you suppose rock density exceeding water density limits water penetration into the crust?
      Still, heat from the Earth’s interior warming the ocean would increase snowfall over continental ice sheets. The heat (put into water vapor) would be released into the upper troposphere where most would escape to space.

      • rock density exceeding water density limits water penetration into the crust?
        sand is denser than water, yet water will not sit on top of sand. it must first saturate the sand. any defect in the rock, water will find a way to flow through and around as it seeks the lowest level. however, there comes a point where the water turns to super critical steam under pressure, at which point it can fall no further. it would not surprise me if someone was to one day find this layer forms the crust mantle boundary.

      • Yes, water does penetrate via voids in the sand. The question is whether the temperature at the depth at which rock density closes those voids is higher or lower than the boiling point of water – at the pressure of that depth. Have you any idea what the boiling temperature of water is below the sea floor, and at what depth that floor is compacted too tightly to allow water penetration? The fact that water temps at the sea bottom are barely above freezing indicates steam is not being generated underneath the sea bottom.
        I imagine that places where water can penetrate to a level where the temperature exceeds its boiling point is confined to localized hot spots, such as the Yellowstone caldera.
        On the question of whether heat released from the Earth’s interior can initiate an interglacial period – I can see that sea ice could be melted over a hot spot, with an increase in snowfall over continental ice sheets following. That is not the recipe for initiating an interglacial.

      • Ferdberple, you say “however, there comes a point where the water turns to super critical steam under pressure, at which point it can fall no further.”
        I do not follow your reasoning, as the critical point of water is the point where pressure is sufficient to prevent water from becoming gaseous. That is, water has no boiling point above that pressure.
        So, if water penetrates to a depth in the crust where the temperature is at the boiling point of water, but the pressure is less than the critical point of water, that water can vaporize. It would then rise, and that depth would indeed mark the lowest level water could penetrate in that local, for a while. Water boiling absorbs great quantities of heat, soon cooling the crust at that level below the boiling point of water (at that pressure). Then the water penetrates further. This process would continue until water penetrates either to a level where pressure squeezes voids shut, stopping further penetration, or the critical point pressure is reached.
        Once water penetrates to a depth where the pressure exceeds the critical point of water, it is not possible for that water to become steam (vapor). The water can penetrate deeper if there continues to be voids within the rock. Steam has no possibility of limiting further water penetration into the crust. Only porosity of the rock matters below the level where critical point pressure is reached. Rock density would be the limiting factor in this case, also.
        As the pressure at an ocean depth of a mere 7,000 ft is greater than the pressure of the critical point of water, steam cannot exist under the seafloor, and cannot play a role in limiting water penetration into the seafloor.

      • I suppose I should cover my bases (baseball euphemism) by mentioning that 2 things happen when water boils:
        1. Each water molecule gains enough energy to break the bonds binding it to its neighbor water molecules.
        2. Separation between water molecules lowers the density of the swarm of loosed water molecules.
        Above the critical point of water thing 1 happens, but not thing 2, due to confining external pressure. No drop in density means no increase in buoyancy – no resistance to deeper penetration into the seafloor should there be an available path.

    • IMO …. the warm and cold pools are strictly water based n the oceans. The speed of the system is what determines the climate. If the system slows, the water at the poles cools and the water at the tropics warms. Since there is less heat to be lost at the poles, the entire globe warms. The energy is translated into kinetic wind energy that speeds up the system. That pushes the warm water to the poles resulting in a sudden warming of the climate, while water in the tropics continues to warm but is diluted with upwelling water. As such the system cools more slowly,
      That’s just my uninformed opinion.

  10. “you need something that raises temperatures in a hurry, which requires a large “warm-pool” to draw from. up-welling unfortunately works in the opposite direction. it is large “cold pool”.”
    WR: It is enough to create (!) a warm pool at the surface, which happens as soon as the cooling (upwelling) has been put on ‘off”.

    • a warm pool at the surface
      but that cannot explain the deep ocean warming. if you create the warm pool at the surface through reduced upwelling that would cool the deep ocean, absent heat from within the earth. the opposite of observed.

      • Ferdberple: “a warm pool at the surface ===== but that cannot explain the deep ocean warming. if you create the warm pool at the surface through reduced upwelling that would cool the deep ocean”.
        WR: Deep ocean cooling takes place by the sink of salty and most times very cold water. After (!) surface waters warmed, less cold water is sinking down. Because the deep sea is ‘refreshed’ by less cold water, after some time deep sea temperatures rise. But because of the quantity of water involved, this process is taking a lot of time and cannot be the cause of the rapid (!) rise in temperatures.
        But, also, every rise in deep sea temperatures will help the warming of the surface, because upwelling waters will have a higher ‘start’ temperature. But the process of deep sea warming is relatively slow.

      • “.. and cannot be the cause of the rapid (!) rise in temperatures. ”
        are you calling 20.000 years “rapid”?
        For a geologists, it many be fast, In terms of ocean circulation that is very, very slow.

    • What’s the possibility that the large warm pool is a pool of surface water that is heated in the tropics, but then moves to the poles?

      • Dr Deanster: “What’s the possibility that the large warm pool is a pool of surface water that is heated in the tropics, but then moves to the poles?”
        WR: I suppose this is exactly what happens as a Glacial ends. In the glacial the ‘warm pool’ in the tropics is not only small in extent (you can only find tropical water at the lowest latitudes) but also very undeep: only the highest layers of the ocean are warm. In the Pliocene warm period, the warm surface layer extended farther north and farther south and the layer of warm water was extending deeper. Less cold water could reach the surface. As soon as ‘warming’ started, the oceans started to fill up. The warmer piled up water east of Indonesia was able to reach again the Indian Ocean and was raising the temperatures of the Indian Ocean. The Argulhas Stream again started to push warm eddies around South Africa, warming the Atlantic. The warmer tropical waters north of Brasil could again enter the Caribbean, warm further there and pass Florida again, sending warm water to the North Pole.
        That warm water melted the ice rapidly and advected much warmer air to the Eurasiaon continent, starting the snow melting process, and so diminishing the albedo. Together with other influences (like dust) this process is to my opinion what happened at the end of the Glacials.
        I even don’t exclude that the piling up of warm water east of Indonesia/Australia (where nearly all sea streets were blocked by the low water level) resulted in massive El Nino’s that on the right moment (orbit) could have played a role in enhancing the initial warming effect.

  11. Interesting discussion. What is the ”temperature” of the earth’s surface depends on just how deep one goes in the oceans, and how much the surface layer of the oceans interacts with the deep water, and how much both interact with the atmosphere. A bit complex.

    • “What is the ”temperature” of the earth’s surface depends on just how deep one goes in the oceans”
      WR: An interesting number is the following: the average temperature of ALL ocean water is only 3.9 °C. Mixing all ocean water will result in an ocean surface temperature of only 3.9 °C.

      • an ocean surface temperature of only 3.9 °C.
        the simplest solution to global warming is to increase upwelling via OTEC technology, using the heat differential between the surface and deep ocean to lift cold water while generating power.
        OTEC generation runs 7x24x365 without any fossil fuel, and it can be used to increase fish stocks by lifting nutrient rich deep ocean water to the surface, similar to what happens with anchovies off the west coast of south america.

      • Geo engineering surely is a possibility if warming would be dangerous. The cooling potential of the deep sea is enormous. But, in the end, the deep sea will warm by the continuously mixing of the warm surface layer with the cold deep water.

      • “the simplest solution to global warming is to increase upwelling via OTEC ”
        You are assuming that global warming is due to CO2 ! Prove it.

      • Ocean Thermal Energy Conversion (OTEC)
        Fred: Cold water sinks because it is heavier and more saline. How much of the energy recovered from temp difference is required to pump cold water up against the gravitational pressure gradient?

      • WonkyPedia: Early OTEC systems were 1 to 3 percent thermally efficient, well below the theoretical maximum 6 and 7 percent for this temperature difference
        .. and how much of that megre 6% is lost in pumping ?

      • WP: “… with one Lockheed design consuming 19.55 MW in pumping costs for every 49.8 MW net electricity generated”
        ” A 100MW power plant would be expected to pump on the order of 12 million gallons (44,400 metric tonnes) per minute.”
        That’s a COP of about 2.5 : 1 , similar to land based heat pump system.

  12. Wim Röst
    Very interesting evidence, exploration and arguments.
    Now what causes the wind to change?
    That suggests exploring the earth’s tropical troposphere to polar temperature difference driving earth’s winds as a heat engine. The poleward heat transport in turn drives the wind and from that the lattitudinal winds by the Coriolis effect. Note especially wind energy WK in Fig. 7 in:
    Anastassia M. Makarieva1,2 et al. Quantifying the global atmospheric power budget Atmos. Chem. Phys. Discuss., doi:10.5194/acp-2017-17, 2017
    Then compare David Stockwell’s: Accumulation of Solar Irradiance Anomaly as a Mechanism for Global Temperature Dynamics
    Article · September 2011

    Here is presented a novel empirical and physically-based auto-regressive 9 AR(1) model, where temperature response is the integral of the magnitude of solar forcing 10 over its duration, and amplification increases with depth in the atmospheric/ocean system. 11 The model explains 76% of the variation in GT from the 1950s by solar heating at a rate of 0.06 ± 0.03KW−1m−2Y r−1 relative to the solar constant of 1366Wm−2 12 .

    Stockwell’s analysis gives a 90 deg (or Pi/2) lag of the ocean temperature from the solar driver.
    What you have shown would then become a feedback to that tropical-polar temperature difference and accumulative solar irradiance driving the wind.

    • David: “Now what causes the wind to change?”

      “What you have shown would then become a feedback to that tropical-polar temperature difference and accumulative solar irradiance driving the wind”
      WR: so far, my guess is that orbital forces change both the winds and the tropical-polar temperature gradient and as a third one, they change the length of seasons. The last one is important too, because [the quantity of] upwelling is season-specific. I possibly will come back on this subject in another post, later.

  13. A sawtooth waveform can be constructed by summing harmonically related sinusoidal signals. The 21K year precession of perihelion, 41K year cycle of axial tilt and the 120K year cycle of orbital obliquity are roughly sinusoidal and approximately harmonically related to each other so a sawtooth like pattern emerging from their combined effects is not unusual.

  14. Hi Wim. At the last glacial max there may have only been a Hadley cell and a Polar cell, which could result in different winds. Also the sealevel was 120 m lower, further from big land mass. Less cloudcover from reduced GCR would help also. Would the dust level transport necessarily be a proxy for strong winds? How big were the particles?
    Now with the quiet sun coming up we have a slowly increasing amount of Galactic cosmic rays GCR. That means we have more clouds. Which means more cooling. Since December in 2014 to now GCR has increased 13% in California and 19% in New England. This should help in cooling the oceans as well.
    Minister of Future

    • Hi Pearce, interesting point the lower sea level. First of all, it raises the quantity of land surface and diminishes ocean surfaces. This will result in other temperature and wind patterns over large surfaces, influencing upwelling. Also currents are blocked, for example in the Caribbean and between the Indonesian Islands. Second, upwelling places will change and as the underwater topography plays a role as well, upwelling will surely show a different pattern.
      To understand what happens at the end of a Glacial, we should have a look at the oceans in the state that sea level is 120m lower as today. And we must know the Last Glacial Maximum’s weather pattern and the resulting winds.

  15. Andy May,
    A few quick and dirty remarks…
    As already said by Michael Palmer, dust deposits – at least in Antarctica – show the highest wind strength during glacial periods. Be it that in the same period the air was much drier and thus far less precipitation – more dust retained in the air. Changed wind strength / directions is not as sure as one need to have for this theory.
    Second, the deep ocean temperature seems to go up and down more or less synchronous with the surface. That means that the whole ocean mass is rapidly warming and slowly cooling, not the surface alone. That is only possible if the surface – deep ocean circulation is at full speed, thus with the normal upwelling and sink speed…

    • Second, the deep ocean temperature seems to go up and down more or less synchronous with the surface.
      yes. which requires energy to be added to the system, not simply moved from one place to another. in addition, you need something to explain the stair-step, pulse like signal of the inter-glacials. You need something that is sudden in warming but slow in cooling. The changes in insolation and or CO2 do not explain why warming is more rapid than cooling. They would give a sinusoidal patter, rather than saw-tooth.

      • CO2 positive feedbacks could give a saw-tooth, but this would require larger swings in insolation. otherwise the climate would latch in the warm or cold phase of the glacial/interglacial. as things are, ice ages end when co2 is low, and they begin when co2 is high, the opposite of what is predicted by ghg theory.
        milankovitch was rejected because insolation changes from orbital mechanics are not sufficient to explain the observations. it was only after deep ocean spreading confirmed the pattern of ice ages that milankovitch cycles gained acceptance.

      • Ferdberple: “milankovitch was rejected because insolation changes from orbital mechanics are not sufficient to explain the observations.”
        WR: My guess is that changing weather patterns corresponding with changing insolation circumstances create less and different winds, diminishing the upwelling and so diminish the cooling of the surface of the oceans, resulting in surface warming. There will be more water vapour in the air and a higher percentage of water vapour will have a warming effect: water vapour is by far our main greenhouse gas. And we know that the Glacials are characterized by very big deserts, showing the low degree of moisture in the air. Cooling the atmosphere.
        So for the development of an interglacial my explanation would be : ‘Milankovitch’ in combination with the behaviour of the oceans (and resulting effects).

      • ferdberple,
        Indeed, the “feedback by CO2” theory mainly looks at the glacial-interglacial period, as during the about 5,000 year warming the temperature and CO2 rise in parallel, with some 800 years lag for CO2, thus with a large overlap, which allows for a positive feedback.
        Problem for that theory is that during the much longer period that temperatures did drop after the last interglacial – the Eemian – CO2 remained high and only started to drop when temperatures were already back at a new minimum (and ice sheets at a maximum). The subsequent drop of ~40 ppmv CO2 had no clear effect on temperature or ice sheet formation…
        Thus anyway, the effect of a 40 ppmv CO2 change (up or down) has little effect on temperature:
        Where deltaTs(corr) is the “corrected” temperature (based on dD) according to Jouzel, another attempt to “adjust” past temperatures more in line with theory…
        Ice sheet volume is based on delta18O in N2O, as that seems to be a good -inverse- proxy (already inversed and scaled in the graph to show ice sheet changes), I don’t know the physical base for that assumption.
        That CO2 levels did remain high is no artifact of ice-gas age difference dating, as CH4 follows temperature far more closely while in the same gas phase as CO2…

      • .

        otherwise the climate would latch in the warm or cold phase of the glacial/interglacial. as things are, ice ages end when co2 is low, and they begin when co2 is high, the opposite of what is predicted by ghg theory.

        You are still not getting what positive feedback means. It is NOT the cause, it is a feedback. If CO2 was high before deglaciation it could not provide a +/ve f/b. This is only contrary to GHE theory if you regard GHE as the principal cause, as Al Gore dishonestly tried to suggest in his Convenient Untruth film.
        The cooling is not gradual but a series of relatively rapid ups and downs, where the max is drifting lower.
        There is a difference between the waming and cooling processes. Which may also be due the presence of life processes. Don’t expect a one variable explanation to climate that has been the error of the last 30 years of pseudo science.

      • Ferberple
        CO2 only rises in the atmosphere after atmospheric temperature rise. It takes this temperature rise to create the disequilibrium to cause the transfer from sinks.
        In an equilibrium of this type, this causes the relative density of atmospheric CO2 to reduce. Yes reduce, density is lower.
        There is absolutely NO thermal increase due to CO2 during a rise from glacial to interglacial.
        The red team needs to ask the blue team for a copy of the chart showing that density of CO2 is higher during this phase.
        Surely they have proof of their own theory. How can they model without proving their theory.
        If I walked into the CAGW experts modeling office’s, I would expect this chart to be like a shrine that they pay homage to. Almost like wall paper.
        Strangely I have never seen one, ever, at all, zilch, just talk of ppm. Has anyone else?
        Dear CAGW modellers, please show me this chart. A simple picture.

    • Ferdinand: “dust deposits – at least in Antarctica – show the highest wind strength during glacial periods”
      WR: that suggests that wind speed would be lower during the (start of the) interglacial
      Ferdinand: “Changed wind strength / directions is not as sure as one need to have for this theory.”
      WR: see my comment above on: pearce m. schaudies July 17, 2017 at 11:00 am
      Ferdinand: “Second, the deep ocean temperature seems to go up and down more or less synchronous with the surface. That means that the whole ocean mass is rapidly warming and slowly cooling, not the surface alone.”
      WR: fig. 2 gives this suggestion, but simple logic tells me that it is easier to warm a thin surface layer than the whole deep ocean. So far I did not find support for a ‘rapid deep sea warming’. We know that in summer time the surface of a cold lake will warm rapidly if there is no wind. Strong winds will enhance the mixing and upwelling, diminishing the surface warming and creating warmer deeper layers. With strong winds: there will not be a rapid surface warming.

      • Wim,
        Dust deposits in Antarctica seems to be more a matter of retreat/advance of glaciers in Patagonia than of global wind patterns:
        The deep ocean temperature changes seems as fast as ice sheet formation / sea level drop (thus surface temperatures) during glacial periods:
        Which points to rather synchronous surface – deep ocean temperature changes and an intact upwelling/sink flux…

      • Hi Ferdinand,
        ‘Dust’ is not my point. It’s the oceans and especially the upwelling in the oceans. But checking the abstracts in your links I found the following sentence (2nd link): “This pattern suggests a causal link involving changes in temperature, in rock flour availability, in latitudinal extensions of the westerly winds and in foehn winds in the southern Pampas and Patagonia.”. Winds and wind changes play a role. We know the eolic sands and löss in Eurasia, in zones from east to west. Deposited as I ever learned when the ice was retreating and the barren ground was too cold for plants and wind was not obstructed. Sand and löss transported (as I have ever learned) by very strong winds, reaching far into the continent.
        Your third link is – as I understand from the abstract – referring to the change in deep ocean temperatures in the (slow) downgoing phase. And that is exactly what I expect: lower deep sea temperatures that result in lower surface temperatures that result in ice and snow. In the downgoing phase.
        The upgoing phase is different. What is the cause of the rapid rise (think in hundreds of years) in temperature at the beginning of the Holocene? See figure under Wim Röst July 17, 2017 at 1:17 pm. Here the deep sea can’t play an important role because in some hundreds of years no water mass of 1.3 billion km3 will raise a two degrees. Besides of this, we are missing the reason why the whole deep sea would rise in temperatures that quick and at that moment.
        For me, to explain the rapid rise of surface temperatures in the beginning of the Holocene only the ‘putting off of ‘the water cooling from below’ remains as a good explanation for those very rapid rises at the beginning of that Interglacial. You MUST turn the cooling [partly] off, to get such a rapid warming. Nothing else changes temperatures that fast. And because other weather patterns (wind) play the dominant role in upwelling, putting off the upwelling [for a certain percentage] would be a very good option. Wind stress acts exponentional on the water surface. A relatively small diminishing of ‘wind’ has bigger effects on the diminishing upwelling. Which has temperature effects which is changing the gradient and the position of pressure areas which are changing the wind speed and wind directions.

      • If I may add I would expect wind to reduce water temperature by another mechanism as well, evaporation. This is what causes lake effect snow. Although moving air colder than the water will increase the effect and therefore the cooling, in theory at least, even moving air that is warmer than the water could cause some cooling as well. I have no idea how significant this would be but adds to what you suggest, something which sounds very plausible to me.

      • Michael Keal, evaporation is an important cooling factor, but it is especially important on the other side of the warming spectrum. As Willis Eschenbach on this site explained, evaporation (and convection of the air that is lighter by the water vapour) is a limiting factor as water is warming. See his thunderstorm posts. It gives a kind of an upper limit to ocean water temperatures. In this recent post he noted: “Figure 9. As in Figure 8, but showing just the ocean. Note that almost none of the ocean is over 30°C. N = 43,350 gridcells”. Almost none of the gridcells has a yearly temperature of over 30 degrees C. Evaporation (and convection and the by convection enhanced winds at the surface) cool the water. Processes that are exponential and therefore show a higher cooling effect as the temperatures of surface waters rise.
        In the cold fase (Glacial) however, the low temperatures do the reverse: in a cold period, evaporation is diminished strongly, resulting in a lot of deserts world wide. No evaporation – no rain, with deserts as a result. But in warming, evaporation plays an important role. Water vapour is our main greenhouse gas and any warming of the sea surface at the end of a glacial will result in more water vapour in the air: resulting in a radiation feedback effect that enhances the initial warming. Until evaporation and convection (and clouds) stop the warming of the sea surface.
        During the Glacial the lack (!) of evaporation (by the low temperatures) result in a direct warming effect for the ocean surface. The lack of clouds makes that the sun’s energy is reflected by less clouds. Therefore, a higher percentage of sun energy is disappearing into the oceans. In this way, the functioning of the ocean system is limiting the cooling down as well.
        Oceans limit temperature changes both on the upper limit and on the lower limit. Without understanding the oceans, understanding ‘climate’ is not possible.

      • Wim,
        Dust is not my point too, but as an indication of changed wind patterns and reducing upwelling it is not a good proxy, that is what the references say. All what can be said is that during glacial periods there is more wind (higher temp. gradient) than during interglacial periods. That doesn’t say anything about the possibility of a more or less sudden stop/reverse of the trade (and other) winds which pull off the deep ocean upwelling in the main upwelling zones at the start of the temperature increase …
        I still think that the warming and cooling of ocean surface and deep oceans is more or less synchronous (of course with a lag of the deep oceans and less temperature change). If the surface-deep ocean circulation remains more or less constant, all what you need is more or less insolation. A few % more or less clouds can make a lot of difference over 5,000 years…

      • Ferdinand,
        There are many unknown factors in the past. Clouds are surely one (and an important one) and ‘wind’ is another one. We hardly realize how fluctuating wind is. On every time scale and at every scale from local to world wide. When we take ‘wind’ worldwide and for whole years the image should show a more or less stable view. But this one is the reality:
        What is shown is the wind speed (not: direction) of a highly variable wind. Even on this small time scale (only 40 years) we see yearly variations of a ten percent. Which is much more than we need to influence dramatically the average temperature of the ocean surface layer by a change in upwelling.
        And there are more processes important. The role of intermediate water – nearly nowhere mentioned – might be huge as well. And the time scale at which intermediate water is circulating is much shorter than the one of deep water. See my comment at Ptolemy2 below.

  16. Mr. Rost:
    Thank you for pointing out the non-consideration of what could be a very significant “forcing factor” – presumably no modeling has yet been done, and would likely require significant and expensive run time on a super computer to check it out.
    Sounds like you have the basis for proposing a very worthy study.
    That the existing models that are relied on by the warmists ignore this factor, the science must not yet be “settled”, huh?

    • Mr. Truitt, thank you for your compliments. I agree that ‘Oceans’ possibly are the big missing link, completely denied by the official science community. All are ‘looking up’ (CO2), hardly no one is looking down (oceans), there where the most important processes for the Earth’ climate are happening. If such an important factor (oceans) is missing, no prediction can be right.
      There is more to write about the oceans, this will not be my last post. And I hope ‘oceanic research’ will be a main factor in future climate research. Which is needed, we hardly know anything about the oceans. And so about the climate. About 71% of the surface of the Earth consists of oceans …..

  17. What about a little theory that explains most things.
    It don’t need positive feedback (the contortions here are going from bad to worse) ,
    It don’t need an alkaline ocean to ‘outgas’ an acidic species (it therefore fits the ideas of entropy)
    It actually obeys the laws of thermodynamics – namely that heat energy always flows down a thermal gradient.
    It is a circular (chicken & egg) situation so endless argument will ensue about cause & effect. sigh
    Where it will cause ructions is that it involves slaughtering the Green House Warming Effect.
    OK. Written as a BASIC program.
    10 Everything is lovely on Earth. The climate is temperate and lots of plants are growing almost everywhere.
    20 Plants absorb CO2 into living plant tissue
    30 Plants get old & die
    40 Dead plant remains fall into the surface soil and decompose as fast as any soluble nitrogen is available and allows
    50 Decomposition attacks the mineral fraction of the soil – releasing much needed nutrients to the plants.
    55 The soil becomes less fertile over time because of this. This is the slow decline into a glacial.
    60 Decomposition releases CO2
    65 The (almost universally) perennial plants form a canopy to slow/prevent its escape to the wider atmosphere
    70 Soil reserves of carbon (as organic dead plant material) rise as soil mineral fertility falls
    80 As soil fertility falls, plant growth slows – CO2 absorption slows and atmospheric CO2 levels rise
    85 While plant growth slows, decomposition does not – CO2 levels really start to rise
    90 High levels of CO2, by virtue of its high molecular weight and high emissivity, cool the planet
    100 Plants are in a jam – low soil fertility and falling temperatures. Large parts of Earth take on a desert climate 105 High latitude deserts are cold places.
    110 Ice advances from the poles, covering what fertile soil there was left
    120 Earth becomes a glacial snowball. Icy covered at top and bottom with a band of mostly desert around the tropics
    125 Lots of desert means lots of dust – as seen in ice cores from glacial times.
    130 Low temperatures promote high-speed (laminar flow) winds over the flat ice covered terrain to help spread the equatorial dust around.
    140 Dust accumulation (rising albedo) and slowly falling CO2 (as it rains out into the ocean – never to return) allow things to gradually warm.
    150 Ice start to melt at low latitudes revealing Fresh New Rock.
    155 The few remaining plants on Earth move into it with relish and grow like weeds.
    160 They slow the winds and moderate the temperature extremes via their water retentiveness.
    170 More ice melts, revealing more newly ground-up fertile dirt
    180 Plants jump into that too and spread rapidly away from the tropics. Hence the rapid rise out of a glacial.
    190 Goto 10
    200 End

  18. Win
    During glacial to interglacial the ocean surface rises about 135 meter’s, this water coming from the melted ice, travelling across land and warming etc.
    This has the potential to increase sea surface temperatures warming the atmosphere positive feedback.
    We have seen in the past 30 years the effects of increased atmospheric circulation and Arctic intrusion. In effect the heat at source namely El Nino and the polar increases are the same. Heat transported. In effect double counting.
    There is also a big difference between wind speed and volume of wind. As air increases in temperature the volume increases also the moisture carrying capacity.
    Stimulating discussion

    • Over the past 30 years there has been a very clear example of positive feedback, nothing to do with CO2, just simple heat source and transport but noone is looking.
      More interested in discussing one hundreths of a degree.

    • Ozonebust, your comment makes me think about the following. During the time the sea level was 135m lower (or a bit less, numbers vary between max 120 – max 135m), large parts of the continental shelves became land. Sea surfaces shrunk. This means that there is a change in the land/ocean ratio. Why is this important?
      Looking at the average temperatures for land and ocean, I noted that ‘oceans’ on the average are many degrees warmer than ‘land’, measured over the whole year. An important fact. Oceans with their high heat content are able to retain heat a long time. They don’t cool quickly. And the sun can easily enter in water surfaces and raise temperatures deeper than on land. Average water surfaces are far warmer than average land.
      When there is less (warm) sea and more (cold) land as during the glacial when the sea level is 135m lower, ‘warm surface’ area is diminished relative to ‘cold surface’ areas, that have been extended. This ratio change changes the average temperature of the Earth: downward during the glacials as ‘land’ is gaining, upward during the start of the interglacial as ocean surfaces extend again. Another temperature rise enhancing factor.

      • Win, thanks for the detailed reply.
        Averages are misleading. Mother earth does not work on avarages, that is why things change.
        On average there is not enough strength in the sun to cause sunburn. Guess what my skin surgeon relies on it.
        The sea ice melts in summer not winter. It is inhibited in growth in winter by winds, aided in growth by winds also.
        Temperature intrusion is also an enemy.
        Averaging hides the signatures that you are looking for.

      • Ozonbust, thanks for your reply. In some comments below you can see that I do have an eye on regional developments. Like you, I think regional developments and regional effects might be of decisive importance. Averages don’t say everything, but they have an advantage: with one number they can express the direction of changes.
        By the way, you changed my name in a pleasant way: Win, instead of Wim. I like that! I only wander whether it is just a compliment or a prediction 🙂

  19. Maybe there is a tipping point for the ozone layer when Earth gets at that extreme cold temperature. We see this in Antarctica.
    Earth would lose its UV protection which would heat the oceans and melt the ice in an unprecedented short time.

  20. Why is it an exponentially decaying saw tooth of sorts? Because there’s a thumping great enthalpy capacitor in the loop with slower diffusion in the solid than liquid state. Little to do with CO2 going in or out of solution or radiative tiddly-winks. Just water and Milankovitch.
    Radiative myopia is bad enough, now it seems convective myopia is on the rise 🙂

  21. With the defining feature of glacial vs interglacial periods being the growth and decay of fresh-water ice sheets, of a volume approximately half that of the warm surface layer of the ocean… It always surprises me that it is “less wind” that inhibits upwelling, and not “lower density” surface water as a result of a positive fresh-water balance.
    I’ve seen it argued both ways WRT AMOC and whether fresh-water balance in that region controls it, but what about the tropical pacific or southern ocean? (in the context of a glacial onset and an excess of evaporation over precipitation over the entire ocean). The cumulative effect is on the order of 20g/m^3 over the entire “72.4 million cubic kilometres of relatively warm water” (even if it is spread over ~50,000 years)

    • Brigantine: “With the defining feature of glacial vs interglacial periods being the growth and decay of fresh-water ice sheets, of a volume approximately half that of the warm surface layer of the ocean… It always surprises me that it is “less wind” that inhibits upwelling, and not “lower density” surface water as a result of a positive fresh-water balance.”
      WR: The density of sea water is lowered by fresh water, brought by rivers or rain. It plays certainly a role, a very important role even. But a smaller role in regard to upwelling. The power of the winds is that big, that it blows the ocean’s warm upper surface layer away. What automatically comes up then, is the upwelling water from below.
      Later more about the role of salt content.

  22. A thought popped into my head while reading this article and all the comments. Let’s suppose that at the end of a glaciation, when it gets lovely and warm, the Arctic Sea Ice starts to melt, a little at a time, (in the summer obviously) and that it continues to melt until eventually a point is reached where we really do see an ice-free Arctic ocean in the summer. When this happens the heat lost to space increases as the sea is no longer covered by an ice blanket. (Not much solar energy will be absorbed by the water due to the oblique angle of incidence of Sunlight up there.) This is exacerbated by over-turning of the Artic Ocean waters due to the fact that the wind blows like mad up there and apparently always does.
    Initially, with the extra water vapour coming off the sea this will increase the snowfall in Greenland and as it gets going over the years will spread further South each winter to Canada and then the US.
    Of course as the temperature starts to drop a point will be reached where the Arctic sea ice will start to increase again so there may be a few false starts but eventually it will just carry on dropping…

    • Michael Keal, I agree fully with you. An ice free Arctic can be an important factor in a next ‘cooling down’. First because of the evaporation effects. An ice free Arctic is cooling the water below. An ice covered Arctic always was preventing energy loss at the surface. Second and for the next glaciation potentially very important is the enhancing by an ice free Arctic of snowfall. We already see an earlier snowdeck in autumn. More evaporation plays a role: more water vapour, more snow, more albedo resulting in lower temperatures. An ice free Arctic surely can bring the right conditions for the next and now stronger ‘Little Ice Age’ which could be the start of further cooling in the direction of the next glacial.

  23. The difference in glacier cycles between glacier periods and inter-glaciers have been found to occur by huge changes in the North Atlantic ocean that gradually cool or quickly warm the planet.
    Cold upwelling water on the western side of the North Atlantic only affects Labrador to Iceland during warm periods of inter-glaciers. These have been found to change position with different cooling events ranging from the YD to Full Ice Age and have been linked to the AMOC. The AMOC has a huge influence in how much energy moves into the Arctic Ocean.
    The cool currents are cold up-welling water that can cause the surface to be much colder than other wise with a warm surface current. Increasing these currents on the planet’s surface causes cooling and decreasing these warming.
    The cold-upwelling water western side of the North Atlantic has been found to move across all over the North Atlantic as far South as Spain. Not only does this significantly cool the North Atlantic, but this also prevents the AMOC from moving energy north into the Arctic Ocean. With there being different stages linked that is why gradual cooling occurs and eventually affects the rest of the planet.
    The key location in determining major events in future are involving Greenland and the North Atlantic ocean. These are the first places that change leading to major climate changes mainly associated with large areas of cold upwelling water or much smaller areas of cold-upwelling water like recent times.

    • Matt G, it is very interesting that you ask attention for cold upwelling because of WESTERLIES. Normally most attention in respect to upwelling goes to the main upwelling regions in the tropics, where mostly ‘Easterlies’ provoke upwelling. And the effect of Easterlies in the tropics is different.
      With regard to future cooling, like you I suppose that ‘Westerlies’ play a main role in cooling the northern oceans. A role that will grow as the (orbital) conditions of a next ice age come closer. In the Atlantic the region surrounding Newfoundland is very important too, I suppose. For the Pacific the Sea of Ochotsk (north of Hokkaido, Japan) is an interesting place where important ocean cooling can start. Last year I have been looking at the effect of low pressure areas in that region. The warmer Arctic resulted in more low pressure areas in that region. Early in autumn 2016 very strong western winds (from land to sea) were the result. They caused a high upwelling in the Sea of Ochotsk and surroundings which ended up in a cooling of the North Pacific: the ‘blue blob’ we even now can find on present Sea Surface Temperature maps. In the Atlantic the region around New Foundland can show important cold upwelling as soon as Westerlies up here will gain in strength.
      The northern Atlantic west of Ireland already is cooling down during a lot of years. Recently a fishermen told me that colleagues fishing west of Ireland were reporting rougher weather over there than they experienced in that region 20-30 years ago.
      Yes, Westerlies will play an important role in cooling the Earth in case of a next glacial. When the cooling takes place in the autumn as happened last year in the Sea of Ochotsk, because of a lack of sunshine in the northern oceans during winter time the resulting cold sea surfaces will influence weather during a long period.
      (in La Nina conditions the cold upwelling water provokes more high pressure areas that result in intense sunshine and so in energy uptake (!) by the tropical oceans, mitigating the cooling effect of upwelling on the surface layer. This warming effect is not to be expected in winter time in the Westerlies’ region in the north. Enhanced upwelling will result in colder circumstances during a long period)

      • Wim, my comment has disappeared into moderation for a while. (quite annoying these days) So here’s a short, short version. The lag in ice cores is tied to the THC. Coming out of a glacial, the lag is 800 years and coming out of an interglacial it is thousands of years. That means that the turn over of the THC and the accompanying walker cell easterlies are fastest coming out of a glacial. Thus, the ocean cannot be the cause of the increase in surface temps coming out of a glacial…

      • Afonzarrelli, I hope your comment will pop out of moderation soon. As I understand, you are talking about the delay of CO2 rise after an initial temperature rise.
        Cold fluids can contain more CO2 and more oxygen than warm fluids. Sucking CO2 up by the ocean possibly is a slower process than expelling it. That could explain the longer delay time during the cooling phase.
        More important than CO2 as a greenhouse gas is water vapour. As soon as warming of the surface starts, water vapour is released and it directly (!) starts it’s radiation work. In case of warming or cooling H2O always is the more important one as long as it is not strongly mitigated by other processes as evaporation and convection.
        I must read your original message because I don’t understand your conclusion that the [behaviour of] the ocean cannot be the cause of increasing surface temperatures. Again: no wind, no upwelling. No cold upwelling: automatically a large increase in surface temperatures, first of the ocean surface and soon world wide.

      • Wim Röst,
        The attention is normally regarding the Tropics, but the North Atlantic area has potential for around 4 times the size of the ENSO 3.4 region. Imagine these changes in global temperatures happening initially 4 times larger than the strongest El Niño’s, but instead of lasting for only a season or few, occurring for decades or even centuries and longer. The duration of an event like this would likely be increasingly significant.
        In the North Atlantic ocean though I am still unconvinced that cold upwelling would be the main source by wind and not cold deep ocean current changes surfacing over much larger areas entirely across to Spain for example. Potentially there is the possibility for formation of a polar gyre, where very cold ocean water equivalent to near the Greenland coast now would accompany the area.

  24. The upwelling is an idea to check….. however, it does not produce additional energy fast
    to produce an interglacial as result… plus what should be the timing mechanism that it
    occurs every 100,000 years?
    The mechanism is different, it is the solar movement: The Sun moves back and forth from
    Focus to the Center into the opposite Focus, turms around there and goes back to the first
    focus via the solar system center…….
    The Interglacial is the Sun´s RETURNING Movement within each focus: During this 3-D
    movement, the planets fly more elliptically (spring and fall), thus receiving additional heat
    from the Sun. The fast increase of temps at the beginning of the interglacial is due to the
    Sun in its path now reaching the focal turning point, attracts her planets closer (interglacial)
    and turns around 3x 90 degrees in 3-D fashion to get onto the propoer return path. Once
    this is completed, the planetary orbits are slowly released and temps slowly
    descend (since 80 AD by 0.53°C per millenia). More on this in, See Holocene paper part 1
    and 6 with details. JS.

    • Upwelling doesn’t cause warming to occur in producing additional energy fast. Upwelling prevents the surface water from being warmed by solar energy and therefore no upwelling causes water to pool at the surface that solar energy warms quickly.

  25. Wim, one overlooked clue may be the lag in co2 behind temperature in ice cores. During the warming phase the lag is 800 years, but during the cooling phase it is thousands of years. There is a school of thought out there that the lag is not really co2 behind temps, but rather global temperature (which is represented by global co2 levels) behind temperatures at the poles. If that is the case, the mechanism would be thermohalin circulation keeping global temps cooler (or warmer) than temps at the poles. As the earth warms coming out of a glacial, surface temps grow faster than the deep ocean. Walker trades thus speeds up, which in turn gives us the faster (800 years) turnover of the THC. As the earth cools coming out of an interglacial, the opposite happens. Surface temps are not quite as warm relative to the upwelling waters. Thus walker trades are slower and so also the (thousands of years) turnover of the THC. So, the lag in ice cores may be telling us that coming out of a glacial the ocean is working harder to cool the atmosphere and thus is not the mechanism for warming the atmosphere…
    i certainly am not trying to say anything definitive here (i’m hardly capable of doing that… ☺). i just thought i’d run it by you to see what you think.

    • Afonzarelli, I must think about that. One of the things is, that I am not CO2 focused. I think it is a relatively weak force compared to other forces like the oceans or ‘clouds’. As I already wrote here: Wim Röst July 17, 2017 at 12:33 pm, because of rising evaporation, water vapour is reacting directly (!) on sea surface warming and because H2O is by far the most important greenhouse gas, it will play the most important warming role of all greenhouse gases too.
      The same for the Thermohaline Circulation, THC. The THC is about deep (!) cold water. The THC helped me to discover the role ‘upwelling’ has in climate. Because ‘what goes down, has to go up’. And estimations of downward movements in relation to the THC were available and so I could do a simple calculation. And then I understood what a massive force upwelling had to be.
      But later, I discovered the less known ‘mixing’ and ‘intermediate water’. I must make a post about those subjects also, because I suppose their role is perhaps outnumbering the influence of the THC, at least in the range from ten years to five hundred years.
      Furthermore, the role of temperature changes of the deep ocean is nearly kept out of the attention of climate scientists. While it is of the utmost importance. I will surely inform you more about my thoughts about this subject in one of my following posts.
      So what is happening in the oceans especially at the end of a glacial is more complicated than in the picture you gave us. And, we don’t know enough about how oceans work. In fact we need a three dimensional model in which we know from every cubic kilometre of sea water, what her behaviour is and how her behaviour was. And there are more than 1.3 billion cubic kilometres of ocean water. We hardly know anything at all.
      I am working on my next post. There is more to come.

  26. Hi Wim. In the charts shown in this article by Javier the obliquity starts increasing 20000 years BP. The temperature makes a sudden jump up about 6,500 years later with the Bollinger alerod jump. He states that the reason for the delay is the thermal inertia of the Earth’s oceans.
    He does not go into how exactly the energy in the oceans causes the rapid temperature rise like you are studying. I think the land mass north of 35 degrees must also contribute something. It is not all covered in ice at this time. So maybe to a depth of one meter it can also increase temperature slowly.
    This from the article …
    But unlike precession changes, obliquity alters the amount of annual insolation at different latitudes in a 41,000 year cycle. This is represented by the background color of figure 34, that shows how the polar regions received increasing insolation from 30,000 yr BP to 9,500 yr BP. Since then, and for the next 11,500 years, the poles will be receiving decreasing insolation.
    Minister of Future

    • Hello Ministerofuture, I studied the same graphs and it is clear that in this cold Pleistocene it is very dificult for the Earth to get out of the Glacial State. Everything (!) has got to be perfect for the Earth to be able to make ‘the big jump’ into the Interglacial State that is the anomaly in the Pleistocene. The Earth needs a long run-up and only then and when all other factors are OK, the Earth changes it system to an Interglacial System. I suppose that in the Interglacial State wind patterns are quite different, wind will be less (also because of the vegetation which is diminishing it’s speed) and I suppose that the diminished wind partly ‘puts off the cooling from below’.
      Because of the exponential effects (wind stress is an exponential factor) you don’t need too much change in the wind patterns. Some percents change might even be enough, since the effect of less cooling water counts up every year. If no cooling water from below at all, already has an 0.19 °C effect in one (!) year, a century with only one percent change has the same (initial) effect. Not to speak about 5%. Many of us experienced during life time a change in wind pattern that is much stronger than 5%. I myself (Holland, Western Europe) did so too. Much less wind here compared to 40 or 50 years ago when I was at my bike to highschool, 15 km away. We were very aware of ‘weather’, especially rain and wind.
      The oceans must be ‘loaded’ with energy until the effect of this energy rise, translates into different weather patterns that favour the Interglacial State. Therefore there is a delay of some 6500 year. The oceans have to be warmed.
      The oceans explain why the top of obliquity might be before (!) the Interglacial. You don’t need the direct effect of obliquity, but you need it’s indirect (!) effect. And even after the obliquity effect started diminishing, it is still adding energy to the oceans. For that, the Holocene could develop and remain in the more stable warm period for a 10.000 years.
      But unfortunately, the oceans already are cooling down. Already some 6500 years or so. Preparing for the next Ice Age. The big question is whether ‘man’s influence’ is able to keep the oceans and the Earth from returning to the ‘normal state’ in the Pleistocene: the Glacial. 9 Out of every 10 years in the Pleistocene are glacial years. We are now living in the Pleistocene Anomaly. Humanity thrived in that Anomaly. We should be scared about returning to that Glacial State. Don’t think about what happens to the agricultural production as soon as the Earth start cooling seriously! Cold and dry will be the result.

      • Wim just a small point on one way for carbon dioxide (CO2) to get back into the sea. (This was discussed earlier on.) Consider a raindrop. It formed high in the atmosphere where it is cold. It has a large surface area for its volume. The water it’s composed of is about as fresh as water can be. When it’s time comes it heads towards the ocean picking up CO2 along the way (if it’s not already saturated). At any one time there are lots of them heading into the sea. Although when it is relatively cold and dry (ice age) there will be fewer of those little CO2 suckers scrubbing the sky of the dreaded CO2 there will also be less outgassing as the sea surface will be cold (relatively speaking). Obviously, this is not the only mechanism at work here. My point is it may be bigger than people think!

      • Michael,
        CO2 and water vapor are mainly emitted from the warm equatorial waters, where also the main upwelling is. Thus any extra absorption of CO2 by the raindrops is from the extra releases. CO2 levels up to the stratosphere are near the same everywhere within +/- 2% of full scale, including seasonal changes and the NH-SH lag.
        Further, solubility of CO2 in fresh water is very low, as fresh water has no buffer capacity, pH around 4 at saturation. Solubility gets even lower – for lower pH – with contamination by stronger acids: SOx, NOx,..
        From the engineering toolbox:
        At 1.0 atm CO2, the solubility is about 3.3 g/l; at 0.0004 atm that is 1.32 mg/l.
        You need a lot of foggy m3 air to form 1 liter of rain, that makes that what is absorbed high in the atmosphere is not even measurable in the local CO2 levels. Where the drops fall, if all water evaporates, you can get 1 ppmv CO2 extra in the first 1 m3 of air…
        Moreover, as most of that is CO2 from the oceans, it is just CO2 transport from the oceans to the oceans, as also most water transport via the atmosphere is…
        Which still may be enormous quantities, as lots of water are transported that way.
        If it falls on land, it will dissolve any carbonate rock it will encounter on its way back to the oceans, but even that is a very slow process…

  27. Great article Wim, I fully agree with its conclusions about upwelling. A cold hand from below that can snatch away our surface warmth any time it wants.
    This recent figure from one of Javier’s articles at Judith Curry’s site shows that obliquity Milankovich forcing drives the cycling of glacial-interglacial with a consistent 6,500 year lag. This is probably the time it takes to warm the whole ocean down to the bottom.

    • Ptolemy2 “This recent figure from one of Javier’s articles at Judith Curry’s site shows that obliquity Milankovich forcing drives the cycling of glacial-interglacial with a consistent 6,500 year lag. This is probably the time it takes to warm the whole ocean down to the bottom.”
      WR: Agree. I am not sure whether the whole ocean needs to be warmed. At least important upwelling areas should be provided with warmer upwelling water. Later I will explain more about more types of deep ocean water. For now: ‘intermediate water’ is less deep than ‘cold deep water’ and it’s ‘circulation rate is faster. It is produced in warmer area’s and salinity plays an important role in the formation of that intermediate water. I suppose this intermediate water can play an important role in rapid warming.

      • Javier is wrong, because precession is also required. Look at MIS 7e 250 ky ago, where the interglacial was late. The interglacial here was produced via precessional assistance.
        But even if you champion obliquity, Javier has still not explained why many obliquity cycles are missed out, and do not produce an interglacial. Like 170 ky ago.
        The answer lies in albedo and dust.

      • Ralfellis: “But even if you champion obliquity, Javier has still not explained why many obliquity cycles are missed out, and do not produce an interglacial. Like 170 ky ago.”
        WR: So far, Javier explained a lot. In one of my next posts I will try to give an answer on the question why not all cycles produce an interglacial. The answer might be more simple than we think. And if I am right, we can find the answer in the oceans.

      • Hi, Wim, I was wondering how to contact you.
        The answer to the missing interglacials is given in my paper.
        Basically, the climate is now always biased towards glacial conditions, because albedo trumps CO2 and every other feedback mechanism. And the more polar ice, the higher the world albedo. But the Achillies heel of a glacial world is that same albedo – darken the ice, and you will get an instant interglacial. And the mechanism for darkening the ice is LGM dust.
        Modulation of ice ages via precession and dust-albedo feedbacks.
        It is a simple theory and cycle, that explains every aspect of the interglacial cycle. The only problem for climatologists, is it demonstrates that CO2 plays little or no part in interglacial warming.
        However, your oceanic overturning may well be useful in explaining why CO2 levels drop so far at the LGM. Current calculations suggest a 30 ppm drop, rather than the 100 – 120 ppm fall that actually happens. For the oceans to be responsible for lowering CO2 concentrations by 110 ppm, there would have to be deep oceanic overturning – but an overturning that can release 110 ppm within 5,000 years.

      • Ralf
        The explanation for the “missed peaks” of obliquity forcing is extremely simple. You said it yourself – it’s precession together with eccentricity (which two oscillations are so closely linked that they are almost a unified phenomenon).
        When an obliquity peak coincides with the right precession/eccentricity setup, you get an interglacial. Every time. Without exception, when an obliquity peak coincides with a peak of eccentricity and a peak of the modulation of precession (not precession per se), then you get an interglacial. When an obliquity peak falls at a different precession / eccentricity setup, then you get an abortive stump of a quasi-warming event rather than a full blown interglacial. It is desperately obvious tgat this is a simple resonance related reinforcing/cancelling phenomenon. It’s that simple.
        You don’t need to fear Milankovich as a threat to your beloved dust hypothesis. It is not a zero sum game, it’s not an either or. Dust linked to CO2 starvation is a real and important feature of glacial maxima just before interglacial initiation. But the inherent instability of large ice sheets extending to low latitudes is what allows rapid albedo-driven warming excursions that terminate glaciation. Dust is not uniquely causative of this and you don’t need to launch a CAGW like crusade attacking every other scientific observation connected with glacial cycling that is not about dust.

      • Ralph, I tried to send you my email adress through Academia. I hope I succeeded.
        I think I already had a look on your article before, but with my present knowledge I will read it possibly with different eyes, I suppose. I will try to find some time to do so. Thanks for your comment.

      • >>When an obliquity peak coincides with the right
        >>precession/eccentricity setup, you get an interglacial.
        But that is not true. Precession and obliquity were in synch many times, when there was no interglacial. Which is obvious, because the glacial cycle is composed of four or five precessional cycles – and two or two and a half obliquity cycles. So there are many occasions when obliquity-precession unions produce little or no warming.
        I will get a graph for that.

      • Modulation of precession, not precession itself.
        Curiously, while this also coincides with “local” peaks of eccentricity, thus amplifying the effect of precession, the absolute amplitude of eccentricity seems to be unimportant – due to the wide modulation of eccentricity, some peaks have a much larger amplitude than others. Such that with the larger waves, most of the waveform is above the eccentricity value of the smaller peaks. But nonetheless the pacing of the interglacials follows the local peaks of eccentricity (which also coincide with the precession modulation peaks), and conspicuously not the absolute amplitude of eccentricity.
        I find this puzzling, and it suggests that there is a strong adaptive property of the climate system, so that it is the local oscillations and relative maxima that are more important than absolute values of Milankovich pacing cycles such as eccentricity.

  28. Sound more like a guess, than a science paper.
    The evidence from the Loess Plateau in China confirms that if anything, winds increase during the glacial maximum period. (Aeolian dust grain size increases at the LGM.). Which stands to reason.
    Contrary to AGW received wisdom, wamer temperatures do not produce higher winds. Witness the decline in tropical cyclones over the last two or three decades, as oceans have warmed slightly.
    To produce stronger winds you need a temperature differential, and polar apmplification provides that amplification. (During glacial periods, the poles cool by some 12 degrees c, while the tropics only cool by about 3 degrees.). So the glacial maximum produces a greater temperature differential, and so stronger winds.

    • Ralfellis: “Sound more like a guess, than a science paper.”
      WR: if this means that the paper is easy to digest, than that is a compliment. That’s how I wanted it to be.
      Ralfellis: “To produce stronger winds you need a temperature differential, and polar apmplification provides that amplification. (During glacial periods, the poles cool by some 12 degrees c, while the tropics only cool by about 3 degrees.). So the glacial maximum produces a greater temperature differential, and so stronger winds.”
      WR: The fact that a glacial shows stronger winds, includes that an interglacial shows weaker winds. Weaker winds result in less upwelling and less upwelling enables the surface to warm more and to extend the warm surface layer, both in depth as horizontally.
      The question that remains is whether orbital changes were enough to create weaker winds in upwelling sensitive regions. Matt G July 17, 2017 at 4:49 pm had an interesting comment which draws attention from the well known tropical upwelling areas to the less known northern upwelling areas. When orbital changes warm 65N, the temperature gradient between 65N and the tropics in the south will diminish. This will result in less cooling (by upwelling and mixing) of the seas south of Iceland. As I read somewhere that sometimes the sea ice reached Spain during a glacial, this is exactly the region where a big switch can/will be made. And because of the influence of the Westerlies, the Eurasian land ice could melt rather easily as soon as sea ice disappeared and a Warm Gulfstream could extend her influence northward. The Lauresian ice sheet which is much more isolated from warm western winds (by the Rockies) melted thousands of years later, I read. Which shows the key role the Northern Atlantic must have had.
      So perhaps the above gives the mechanism for how ‘orbit’ and ‘less upwelling’ worked together to create the start of an interglacial.
      And as soon as melting started, things like dust facilitate the melting process and because during the Pleistocene it seems to be more and more difficult to reach an interglacial state, dust is needed too.

  29. Thank you for adressing the role of oceans on termination of ice ages. I think that ocean temperature stratificatin, ocean circulation system and the enormous lid of sea ice played a major role. One question is how oceans can build up energy over thousand of years before it is released into the atmosphere. Some of this is discussed in Science of Doom. There are many posts on glacials and interglacials, called Ghosts-of-climate-past.
    From the discussion there:
    Temperature Gradient between Low & High Latitude. George Kukla, Clement, Cane, Gavin & Zebiak (2002):
    “..At first glance the implications of our results appear to be counterintuitive, indicating that the early buildup of glacier ice was associated not with the cooling, but with a relative warming of tropical oceans.”
    So one theory would be that tropical oceans take up a lot of heat, while ocean currents over higher latitudes fade out. This would build up warm currents at lower latitudes. Combined with ocean temperature and salinity stratification at higher latitudes there cuold be a homeostatic stability for a many thousand years, which at some time would break down.
    Tine L. Rasmussen, Erik Thomsen, Matthias Moros. North Atlantic warming during Dansgaard-Oeschger events synchronous with Antarctic warming and out-of-phase with Greenland climate. Scientific Reports, 2016; 6: 20535 DOI: 10.1038/srep20535: ” During the coldest periods of the last ice age the Nordic seas were covered with a permanent layer of sea ice. The pump stopped transporting the heat northward. The heat accumulated in the southern oceans. However, the warming was not restricted to the south.
    ” Our results show that it continued all the way to Iceland. The warming was slow and gradual, and happened simultaneously in both hemispheres. Little by little the warm Atlantic water penetrated into the Nordic sea underneath the ice cover. It melted the ice from below. Once the ice was gone, the pump started up again, bringing additional warm water into the Nordic seas. And we got a warmer period for 50 years. ” says Rasmussen.
    Large ice sheets continued however, to cover the continents around the Nordic seas. In contact with the warm ocean water they started calving. This delivered icebergs and fresh water into the sea and caused a cooling down of the surface water. The seas were again frozen. And the pump slowed down.
    The warm ocean blob of the ice ages rewrites the understanding of the ocean circulation systems, and how they affected the extreme climate changes of the past. The seesaw was actually more of a ‘push and pull’ system.
    “There are no symmetrical processes in the north and the south — the climate changes were principally governed by simultaneous warming and the constant closing and re-opening of the sink pump in the Nordic seas” says Tine Rasmussen”
    Jenny Roberts, Julia Gottschalk, Luke C. Skinner, Victoria L. Peck, Sev Kender, Henry Elderfield, Claire Waelbroeck, Natalia Vázquez Riveiros, David A. Hodell. Evolution of South Atlantic density and chemical stratification across the last deglaciation. Proceedings of the National Academy of Sciences, 2016; 201511252 DOI: 10.1073/pnas.1511252113: A new study reconstructing conditions at the end of the last ice age suggests that as the Antarctic sea ice melted, massive amounts of carbon dioxide that had been trapped in the ocean were released into the atmosphere.
    “Before this study there were these two observations, the first was that glacial deep water was really salty and dense, and the second that it also contained a lot of CO2, and the community put two and two together and said these two observations must be linked,” said Roberts. “But it was only through doing our study, and looking at the change in both density and CO2 across the deglaciation, that we found they actually weren’t linked. This surprised us all.”
    Through examination of the shells, the researchers found that changes in CO2 and density are not nearly as tightly linked as previously thought, suggesting something else must be causing CO2 to be released from the ocean.
    Like a bottle of wine with a cork, sea ice can prevent CO2-rich water from releasing its CO2 to the atmosphere. The Southern Ocean is a key area of exchange of CO2 between the ocean and atmosphere. The expansion of sea ice during the last ice age acted as a ‘lid’ on the Southern Ocean, preventing CO2 from escaping. The researchers suggest that the retreat of this sea ice lid at the end of the last ice age uncorked this vintage CO2, resulting in an increase in carbon dioxide in the atmosphere.

    • What reason is there for believing that water under the ice around Antarctica was trapped in place and did not circulate away from that region, and instead stayed put for…what, hundreds of years?
      Even if the water did not move, what about diffusion?
      Someone is gonna have to ‘splain this to me a little better before I even think about believing it.

  30. Looking for systems that cause stepped cooling and fast warming in short term time lengths would be logical areas to consider when determining long term time lengths. I am of the opinion that oceanic/atmospheric teleconnected relationships such those posited by the author of this post have so far been ignored for the far sexier solar and CO2 groups. The KISS principle is elegantly boring since it means all systems normal, there is nothing to see here.

  31. With so many things unexplained about the dynamics that produce interglacials, it’s natural that attention should turn to another little-explored domain: the deep oceans. But in seeking explanations, we should avoid positing mechanisms that have not been observed or contradict available oceanographic knowledge. The notion that there is wholesale “overturning” of the oceans, with bottom-water rising to the surface in the tropics, is the unsupported invention of “climate science” desperate for an explanation. Carl Wunsch, the leading expert on oceanic circulation, dismisses the oft-conjectured “global conveyor belt” as “a fairy tale for adults.” See:
    While oceanic upwelling is a common phenomenon, it is restricted largely to shallower coastal waters subject to seasonally varying winds whose Ekman drift carries the surface layers away from the coast, thereby exposing the cooler subsurface layers that rise hydrostatically. In deep tropical waters, there is no such true upwelling that can eventually bring deeper layers to the surface, but only the shallow circulation of horizontal Langmuir vortices due to mass convergence within the ITCZ. By comparison, the much-misunderstood thermohaline circulation is a snail-paced process, which does not involve any wholesale subduction of surface currents, but only of denser strands that mix turbulently with surrounding subsurface waters. The AMOC, for example, thus cannot preserve the sigma-t of water parcels throughout its circuit, as is often mistakenly assumed.
    Certainly, conjectures for the quasi-periodic appearance of interglacials should not exclude the role of oceans as the principal heat reservoir of the planet. It is doubtful, however, that upwelling–particularly of truly deep waters–can play a globally dominant role.

    • A few years back there was a thread here at WUWT in which was had a long discussion of deep water formation, and where and when it happened, and where and when such cold deep water could even come to the surface again…being very cold and salty it is very dense. Dense water will not rise through less dense water.
      Many graphs were posted involving the physical chemistry of water, and how different salty water behaved than fresh water. And water of varying salinities behaves in changing ways as salinity increases.
      Many frequent commenters here said they had never seen several of the graphs I posted.
      And it seemed to emerge from the discussion that in the Arctic, where it seems that most or all of the new deep water forms (deep as in sinking all the way to the bottom), as surface water freezes in the fall, salt is expelled from the freezing water as it freezes, and this has several very interesting and unintuitive consequences.
      Anyway, by the end of the discussion, I was deep in thought, pondering the phase diagram of water, which is published in incredible detail.
      And I realized for the first time exactly how cold the water at the bottom of the ocean really is. It is below the freezing point of fresh water, and it may even be below the freezing point of saline water…under lower pressure.
      In other words, at the bottom of the ocean exists water in a supercooled state…massive amounts of it.
      Physical chemistry can get weird under certain conditions, and extreme pressure and supercooled fluids are some of those conditions.
      A supercooled fluid exists in a state that is like building a house of cards, standing on the edge of a cliff…one nudge and a process is set in motion that is self-perpetuating.
      So, anyhow, if a bunch of water at the bottom of the ocean should, even for a short time, undergo some change in condition, some shock, or dilution, or change in chemistry, and it should freeze…well, what would happen then?
      What would happen if several cubic miles of water and the bottom of the ocean suddenly froze?
      Could it expel its salt, become extremely buoyant (because water expands when it freezes and becomes less dense) and rise explosively to the surface. It would, in the process, drag by entrainment a whole lot of other water with it. It might even cause a sort of chain reaction. Phase changes and chemical reactions are funny that way, especially the coiled spring type where the entire bottom of the ocean is supercooled water.
      So, leaving aside the question of what could start something like that, if it did start, it could be very large and very dramatic and not stop for quite a while.
      What could start it?
      Who knows…lots of possibilities.
      *shrugs shoulders*
      Have a careful look at this phase diagram…particularly the upper left hand corner of the green section…the part that represents liquid water. That nose that juts out. It note that thee pressures in that section of the phase diagram happen to include the range of pressures at the bottom of the ocean in some places.
      Now…anyone know where to find this same diagram for saline water? Does it also have that nose?
      One last question…I have looked for the thread…anyone remember it and have the title or link?
      I and several others posted a bunch of very interesting graphs and charts and the discussion was great.

      • Menicholas, “One last question…I have looked for the thread…anyone remember it and have the title or link?”
        WR: You posted the above graph also on:
        I don’t know whether this is the thread you were searching for. If not, try this way of searching:
        – go to Google Images
        – type words like: “phase diagram water vapour liquid solid WUWT menicholas”
        – search
        If the above thread is not the right one and you remember the content of other graphs, use their characteristics to find them back in the same way as above

      • Menicholas: “A few years back there was a thread here at WUWT in which was had a long discussion of deep water formation, and where and when it happened, and where and when such cold deep water could even come to the surface again…being very cold and salty it is very dense. Dense water will not rise through less dense water.
        Many graphs were posted involving the physical chemistry of water, and how different salty water behaved than fresh water. And water of varying salinities behaves in changing ways as salinity increases.”
        WR: I was trying to understand the behaviour of salty water in the oceans. It is of the utmost importance to understand the behaviour of oceans. When you find back the discussion above, I am interested in what you think that was most important for the behaviour of salt water.
        I am preparing another post (it is one of the concepts that are waiting for finalizing) in which the specific properties of salt (!) water play an important role. It will be very interesting to discuss the consequences. I will keep it simple, but nonetheless, because of its far reaching consequences (in my eyes) it might give interesting views on ‘climate’ and on the development of our climate system in the last 50 million years. Interesting for our view on the future of climate as well.

      • “Crispin in Waterloo:
        “The freezing temperature vs salinity curve is amazing. I never saw that before. I would like to pursue this further to see where water is and the condition and the influence of ice cycles.”
        Yes, very interesting indeed. Boiling point elevation/freezing point depression is of course a very extensively covered subject in most chemistry and physics courses, and indispensable knowledge when covering physical chemistry.
        It does seem to have been overlooked I many of these discussions, which, in retrospect, is odd.
        I found one more chart that gives a better perspective, since the temp vs freezing point chart is in different units than the other chart.
        Since ice does form at the surface, it must be the case, as you point out, that the process is rather more complicated, and that as the freezing progresses, salt is excluded gradually and allows the ice to remain on the surface.
        (Unless one is to think that the ice forms at the bottom, or somewhere in the water column, and floats up to the surface, which I have seen no evidence to believe is the case)
        Otherwise, water would sink before it froze and sea ice would have a hard time ever forming in open water, no matter the temp. It would seem that the whole water column would get very cold and then freeze all at once from top to bottom!
        Here it is, and I agree that this needs a closer look.”

      • Your provocative conjecture that buoyant ice may form from bottom water has never had any empirical indication. On the contrary, what is found in certain isolated locations are hot-water vents (‘smokers”) that send traceable plumes to the surface.

    • Possibly the extreme low elevation (and hence the raised atmospheric pressure) at the sea water surface
      has a major impact on the temperature equilibrium of the surface water due to the reduced rate of evaporation at low elevations. During glacial periods sea water levels are > 100 metres lower than present levels and therefore, because the rate of evaporation is reduced by the raised atmospheric pressure, the equilibrium sea water temperature (taking all other factors into account) will eventually be raised.
      The average annual temperature of water at raised elevations, even at equatorial latitudes, is influenced in large measure by the elevation of the water surface. The comparison of annual average water temps of fresh water lakes in Africa (Victoria, Tanganyika & Malawi) indicates that the major factor influencing water temp appears to be elevation and not latitude.
      Andean tropical lakes at extreme altitude ( above the clouds and therefore subject to unimpeded solar radiation ) are paradoxically colder than temperate seas such as the Dead Sea. The annual average water temp of the Dead Sea is possibly the highest on the globe for a large body of water. The water surface of the Dead Sea is below sea level.
      Therefore it is postulated that during glacial maxima the sea water surface temperature at the equatorial regions will be considerable warmer than the present average of +/- 30C because of the lower elevation and so could be a major factor in the eventual rebound to the next interglacial.

    • 1sky1: “Carl Wunsch, the leading expert on oceanic circulation, dismisses the oft-conjectured “global conveyor belt” as “a fairy tale for adults.” See:
      WR: in this paper “What Is the Thermohaline Circulation?”, the sentence “a fairy tale for adults.” can’t be found. On the contrary. Prof. Wunsch concluded in his Science article:
      “The ocean is thus best viewed as a mechanically driven fluid engine, capable of importing, exporting, and transporting vast quantities of heat and freshwater. Although of very great climate influence, this transport is a nearly passive consequence of the mechanical machinery.”
      1sky1, the expression you use, ‘global conveyor belt’, is not even found in the article.
      The words ‘fairy tale for grown ups’ we can find back in a description of a complaint from Prof. Wunsch against programme makers. See The document is published by Steve McIntyre, Jul 22, 2008. It is about a complaint from Prof. Wunsch against programme makers for being misrepresented in their programme.
      The programme makers told Prof. Wunsch in an initial mail:
      “that they had read reports about the “effects of climate change on the Great Ocean Conveyor Belt and the Gulf Stream and wanted to ask if you agree with the conclusions that they are in imminent danger of shutting down”.
      Wunsch promptly replied on Sept 18, 2006 referring to a popular representation of the Gulf Stream as a “fairy tale for grown ups”: “He responded that this was “absolutely not” the case, stating that “you can’t turn the Gulf Stream off as long as the wind blows over the North Atlantic and the earth continues to rotate!” and went on to describe the ‘conveyor’ as a kind of fairy-tale for grownups”. Professor Wunsch said that “I’m willing to talk about these things. I believe that there are all kinds of things happening in the oceans, many highly troubling, but I also believe that one should distinguish what the science tells us and what is merely fantasy”.
      So far what I have read at Climate Audit..
      Mr. 1sky1, the words you put in the mouth of Prof. Wunsch are nowhere in the paper you mentioned . On the contrary, he said about part of the thermohaline circulation: “you can’t turn the Gulf Stream off as long as the wind blows over the North Atlantic and the earth continues to rotate”
      I can not conclude otherwise than that in your comment you are completely misrepresenting what Prof. Wunsch really said and what he intended to say.
      Your own final statement “It is doubtful, however, that upwelling – particularly of truly deep waters – can play a globally dominant role.” missed any evidence. You nowhere presented the proof that there aren’t many Sv (Sv = Sverdrups = 1 million cubic meters water per second) going down deeply into the ocean. And what goes down has got to go up. And what goes up in the ocean, is called upwelling.
      Can we identify you as a troll, mr. 1sky1?

      • One of the long list of facts of nature that warmists deny is indeed the role in climate of the oceans and their cast heat capacity. For them the ocean is a passive puddle 100 forced in real time be the atmosphere. The absurdity of this position is not important to them.

      • Wim Rost;

        I can not conclude otherwise than that in your comment you are completely misrepresenting what Prof. Wunsch really said and what he intended to say.

        It’s my failing that, in directing readers’ attention to Wunch’s professional views of thermohaline circulation, the impression was created that the words I quoted from memory were contained there. In fact, they come from his monograph on “The Ocean Circulation Inverse Problem,” published by Cambridge UP in 1996. There, in a footnote on p.324, he writes

        [S]uch pretty ideas as global conveyor belts are useful summary devices for unsophisticated audiences–fairy tales for adults. But they are grossly misleading as pictures of how the fluid moves and how it carries properties with it.

        Nowhere do I question that denser surface water sinks, sometimes all the way to the ocean bottom. Of course it displaces lighter water upward. But that is not what we oceanographers call “upwelling.” And the really important aspect that is almost universally missed in “climate science” is that the physical properties change through turbulent mixing. Denser water is always negatively buoyant and as such cannot simply rise to the surface, as fanciful diagrams of “the global conveyor belt” depict. Nothing is more important in determining density than temperature. The idea that near-freezing bottom waters rise buoyantly to the surface to cool it, creating very long climate cycles corresponding to the “overturning,” is risible. There simply is no oceanic overturning in corpore, such as is experienced seasonally in fresh-water lakes.
        Can we identify you as an oceanographic novice, Mr. Rost?

    • 1sky1
      There is one extremely simple and conclusive proof that the deep ocean water circulates and exchanges with surface water, albeit on long time scales.
      It is oxygenated.
      Where does this oxygen come from? Volcanic sources? I don’t think so. It comes from the surface. If there is downwelling of deep saline cold water (please don’t say that you deny this also) when by simple mass balance there must be – and is – deep upwelling also.
      Deep upwelling BTW off Peru 🇵🇪 is what drives ENSO.
      That this simple fact of deep ocean circulation can even be in dispute is depressing indeed about the failed state of knowledge and scholarship about the climate system.
      Look at this previous article here on WUWT. It shows that in hotter periods of earth’s history, like the Jurassic-Cretaceous, the lower layers of the ocean were partly anoxic. This is the consequence of the absence of cold downwelling at the poles.
      Today the deep water is oxygenated. It is MOVING at about 4 mph, the speed of a brisk walk. It is circulating. It downwells and upwells, and is cold. Please start thinking seriously about the climatic implications of this.

      • Deep upwelling BTW off Peru 🇵🇪 is what drives ENSO.
        That this simple fact of deep ocean circulation can even be in dispute is depressing indeed about the failed state of knowledge and scholarship about the climate system.

        There’s a wide continental shelf off Peru where most of the coastal upwelling takes place. It is by no means “deep” in any oceanographic sense. At any rate, the surface temperature in the Humboldt Current never approaches that of the bottom waters, on or off the shelf. And it is not upwelling, as such, that “drives ENSO,” but atmospheric pressure differences that regulate the trade winds that induce upwelling. ENSO does not involve the deep ocean.
        Nowhere do I dispute deep ocean circulation per se–only the egregious oceanographic misconceptions that abound especially in blog discussions of “climate science.”
        BTW, where do you have empirical evidence that “deep water…is moving at about 4 mph” That’s a brisk rate even for a surface current, such as the Gulf Stream, which is driven by winds–not by thermohaline factors.

  32. I never thought of searching like that.
    I was just searching on this site using search terms like sea ice and deep water, but I do not recall if the original article was closely related to that part of the discussion thread.
    Thank you for that idea.
    That thread was most definitely not the one I was looking for.
    I had forgotten about that one, with the guy who insisted that there was no such thing as water vapor, and no such thing as convection, and that dry air was lighter than moist air.
    Reading over it, I cannot understand why on Earth I wasted all that time.
    I wonder if maybe it was a warmista troll sent over to hijack threads by pretending to be a crank.
    No, the one I was thinking of had a very long discussion with dozens of people and had lots of charts of various iterations of the AMOC and the thermohaline circulation, and lots of physical chemistry charts.
    I cannot even be sure how long ago it was.

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