Guest Post by Willis Eschenbach
My business card gives my job title as “Generalist”. Let me give you an example of why this is an advantage in climate science. I worked for a while in the field of low-tech renewable energy. One of the things I did was to work with inexpensive solar water heating. Using solar energy to heat water can be extremely cost-effective. One of the reasons it can work cheaply is that it doesn’t require pumps. The water can be circulated while it is being heated using the principle of the thermosyphon. Here’s a diagram of how a thermosyphon works:
Figure 1. Principle of the thermosyphon. Image Source
The reason the thermosyphon works is because a cold fluid is denser than a warm fluid. As a result, you get a pressure difference in the two legs of the system. This pressure difference works to constantly circulate the water. The water sinks on the cold denser side, and rises on the warm less dense side. Thermosyphon water systems are great in the developing world because they can be built very cheaply, using plastic pipe and 55-gallon drums.
If you’ve worked much with thermosyphon systems, you may have noticed that the system shown in Figure 1 is missing a critical component for successful operation. To work efficiently, the system needs a one-way valve to keep the circulation from running in reverse.
The reason it needs a one-way valve is that at night, the solar collector reverses function, and it becomes a thermal radiator. It radiates away the heat towards outer space. This makes the “Return” leg of the circuit (shown in red) colder and therefore denser than the “Advance” leg of the circuit (shown in blue). And absent a one-way valve, this of course reverses the circulation entirely.
As a result, during the night-time, the circuit as shown takes warm water from the top of the tank and circulates it to the thermal radiator. There it is cooled by radiation to space and returned to the bottom of the tank. It is a reverse thermosyphon system, which will run as long as the water in the tank is warmer than the thermal radiator.
Now, what does a reverse thermosyphon system have to do with the climate?
To elucidate that connection, consider the following situation shown in Figure 2.
Figure 2. Incoming solar radiation and outgoing thermal radiation, Pacific Ocean. The north and south poles are at the right and left ends of the diagram, and the equator is in the middle.
In Figure 2, the sun is warming the surface layer of the ocean at the Equator. At the poles, on the other hand, very little solar energy is absorbed by the surface. Instead, the poles are areas of net radiation to outer space.
Now, considering what we know about reverse thermosyphon systems, in Figure 2 what would we expect in the way of natural thermal circulation?
Since the water is cooled at the poles it will be denser, while the sun-warmed tropical surface waters will be less dense. As a result, the water will sink at the poles and rise at the equator, as shown schematically in Figure 3.
Figure 3. Simplified overall circulation pattern, Pacific Ocean. The north and south poles are at the right and left ends of the diagram, and the equator is in the middle.
Of course, nature is never that simple. In addition to the temperature difference, the circulation is also driven by the salinity difference. Salty water is denser than fresh water, and the polar waters are salty. Since the circulation is driven by both temperature and salinity differences, it is called “thermohaline circulation”. (The circulation is also driven in part by the wind, although that is not included in the name.)
This salinity difference only increases the strength of the circulation shown above. People sometimes ask why the oceans stay so cold when they are always being warmed by the sun. It is because there is a constant stream of very, very cold water being added to the bottom of the ocean by the thermohaline circulation.
To further complicate matters, there is a very small addition of geothermal heat moving upwards through the sea floor. Estimates put this warming on the order of a tenth of a watt per square metre (W/m2).
My back of the envelope number for ocean heating is as follows: one watt per square metre (W/m2) applied for one year will raise a cubic metre of sea water by about eight degrees C. Rough, but useful.
Again using approximate numbers, the overturning of the ocean occurs over something on the order of five hundred years. A tenth of a watt over a hundred years will raise the temperature of the bottom hundred metres of water by eight-tenths of a degree. In five hundred years, it would raise the temperature of the bottom hundred metres by no less than four degrees. In this manner, the icy polar water is very gradually warmed as it moves equatorward.
Now, with all of that as prologue, here’s the question of interest. It has been said that the reason that the warming is currently stopped is because the “missing heat” is hiding in the depths of the ocean … but that the surface layers have not warmed significantly. Many skeptics have said that this is simply not physically possible. They argue that because the ocean is heated from above, the heating would perforce be greater nearer to the surface. They claim there is no possible mechanism by which the deeper layers could warm independently of the surface.
So my question is, given the situation and circulation shown in Figure 3, what would be the effect on the average ocean temperature of a slight warming at the poles?
Well, if the water that is descending at the poles is slightly warmer than in the past, then there will be less cold water added to the bottom of the ocean. With less cold water added to the bottom, on average the ocean depths would warm slightly compared to the past … and the interesting point is, the ocean would warm from the bottom up.
So that is how the ocean depths could warm separately from the surface. And that is how an understanding of low-tech renewable energy systems can assist our understanding of the climate … and why my business card says “Generalist”.
Regards to you all,
w.
A Final Disclaimer: No, I do not think that the current plateau in the warming is caused by “missing heat” hiding in the ocean. And in any case I don’t think that we have the data to measure the ocean that accurately.
I’m just pointing out that yes, it is possible for the ocean to warm from the bottom up—you just need to turn down the volume or turn up the temperature of the polar leg of the thermohaline circulation.
The Consistent Request: If you disagree with someone, please quote their exact words so we can all understand your objection.
In terms of “green” energy, various types of wind and solar are useful for the end-user but not for a power grid. A small wind turbine or solar panels or solar water-heating can decrease a household’s power drain from the grid and may even donate energy to the grid, but it cannot be a major part of a grid.
YOU CANNOT MAKE A RELIABLE ENERGY SUPPLY FROMUNRELIABCLE ENRGY SOURCES.
that has not stopped our legislators in Vermont from decreeing that 75% of all energy must come from renewables by 2032 (not 2031 or 2035) of course they didn’t make it in math and were streamed into social studies and astrology so they could succeed, avoid welfare, and enter politics …
You’d better have lots of rivers suited for dams in Vermont.
If this is the mechanism that can “heat the ocean from the bottom up” and it runs at a speed of about 500 years per cycle, it doesn’t explain the “missing heat” from greenhouse gases suddenly deciding to go into the ocean depths in the 1990s and supposedly heating it measurably at the depths in just a couple decades. There hasn’t been enough time for anthropogenic global warming to have this effect throughout the oceans yet.
Incoming solar radiation is absorbed in the first 100 meters or so of the oceans. It thermally diffuses to greater depths. There are decades long time lags between 700 meter and 2000 m for which temperature gradients have been measured and heat contents calculated. With surface temperatures failing to rise for a few decades, the temperature of the oceans below 700 m will continue to rise from heat that arrived while surface temperatures were increasing. It is simple thermal lag that allows heat to continue to accumulate in the depths. Doesn’t matter. It will never return to the surface to bother us.
Pumps are cheap. Cheap to run. They are now quiet, They enable control.
But the popular GHE is radiative flux only, SWIR, LWIR, microwave, gasses only and does not include the powerful effects of water vapor, latent heat of evaporation, 970 Btu/lb. Even the sensible heat of water, 1 BTU/lb-F, is 4 times the heat capacity of air at 0.24 Btu/lb-F.
http://www.writerbeat.com/articles/3713-CO2-Feedback-Loop
Was hoping the geothermal thing would be developed a bit more. Seemingly neutral to the convective/thermosiphon thing as no obvious relation to latitude. Back of envelope surprisingly high.
The ultimate reason the polar oceans (and thence the entire ocean) cannot be warmed as you suggest is that the polar oceans remain much warmer than the polar atmosphere.
Absolute (not anomaly) data is hard to find but with Bob Tisdale’s help in finding these worldwide series allow direct comparison of absolute ocean and atmospheric temperature from Jan. 2000 to present. After converting from Kelvin it is clear that in the polar bottom water formation areas the ocean was 4-5 degrees warmer than the atmosphere in Jan. 2000.
I have compared each month in the series and there is not one single instance anywhere on earth where the ocean is not warmer than the atmosphere on an average monthly basis.
I think your comment has one of the keys to demolishing the argument, however I spot a flaw with the diagram. Isn’t 0C = 273K?
According to the temperature chart, my home was roughly 0C in Jan 2000. Seems wrong. I don’t think brightness temperature is thermometer temperature.
“The brightness temperature is a measurement of the radiance of the microwave radiation traveling upward from the top of the atmosphere to the satellite, expressed in units of the temperature of an equivalent black body.”
Wow, this from the RSS site:
“Each product measures the mean temperature of the atmosphere in the thick layer.”
So I think the “brightness” defines an actual temperature, trouble is, NOBODY will tell you the altitude of the top of TLT nor at what altitude the mean might actually be measured.
In an abundance of caution working from memory I understated the difference between ocean surface and TLT in the bottomwater formation areas. It is actually 12 deg C, so at a lapse rate of 2 deg C/1000′ the argument holds to a mean TLT measured at 6000′.
It makes nothing but sense that the atmosphere be colder in the bottom water formation areas because these are most often at the edge of the ice and benefiting from the extra density of brine rejection. Why else would the water be freezing?
Anyway, no way to be sure without more information, and thanks for pointing this out.
“The heat is hiding in the deep ocean” is a nice bit to speculate and chew on but how do you prove it? The laws of gravity are proven due to their predictable nature allowing us to get a probe to Mars.
The heat in the ocean hypothesis was after the fact not predicted. In solving crimes, the prosecutor develops theories of how and who committed the crime, the prosecutor does not predict crimes but explains them after the fact. Science is used in that way but science does not progress in that way. If a hypothesis is not predictable, it is not provable or falsifiable and therefore invalid.
Now we have a prediction; it is claimed warming will continue when the oceans release the stored heat. Except it is not testable. Even if a warming trend continued after this flat temperature period, there is no way to prove it was heat released from the oceans and not due to another reason. It is too generalized to be provable. If a cooling trend occurred it is just as facile to claim the oceans are absorbing heat at a greater rate.
Creating new explanations in response to new observations and discoveries is how science works. The issue in climate science is they have yet come up with a predictable explanation of anything. Evolution predicts what archaeologists will find, and evolutionary predictions have consistently been proven true. Climate science behaves like crime fighters who explain observations and events after the fact, not like scientists whose explanations predict observations. In a word, it’s lame science.
Thermal incline.
At 4° water is is dense as it gets.
Blow 4° it rises.
Look at the 4° ice-so line over time
You may find an answer
In the Arctic, the freezing surface concentrates salts in the water below it. That process increases the density much more than changing temperature. That denser water sinks. The process is likely to be the pump action that contributes to the deep ocean “convayor belt”.
Yes, that’s an important factor that Willis left out.
Water reject almost all the salt as it freezes That water sinks drawing more warmer water from the Atlantic. That sounds like yet another negative feedback in the system.
4 is as dense as fresh water gets. Salt water gets much denser. So do some people, apparently.
Add wind, spotty ocean floor heating (very hot to virtually none from place to place), evaporative cooling, clouds, land mass blockages and fresh water additions in various places at various times and one has a very complex system which may behave nothing like what one might expect from the broad generalities expected based upon the averages of the various data. In a word, chaotic. Not to diminish the fact that oceans on a 70% water world are, undoubtedly, major determinants of climate, which, not surprisingly, is also chaotic. They have the ability to accumulate and disseminate heat over long periods of time in a very indeterminate manner.
Is the efficiency of a thermosiphon enhanced by greater temperature differentials between the hot and cold circuits? If so, wouldn’t a warming of seawater at or near the poles reduce the temperature differential between them and the Equator and thus the circulation rate? Additionally, would warmer seawater at the poles have a reduced salinity (due to expansion?), and thus a reduced salinity differential as well, thereby also slightly offsetting the thermohaline circulation? (Of course, increased evaporation may offset any reduced salinity, but it seems likely that Equatorial regions would experience at least some increased evaporation as well.) Moreover, with a turnover rate of 500 years is it likely we’d be seeing an increase, however minuscule, of deep ocean temperatures this early in the game, especially in the presence of confounding factors?
Willis,
Your use of the language is different than mine.
“the water that is descending at the poles is slightly warmer than
in the past”
“the oceans would warm from the bottom up”
In this sequence, isn’t the surface warming first? How do I misunderstand?
When does the water sink? When it’s denser than the water below. When it reaches 4 C it will be, because that’s the temperature at which the density of water is an absolute maximum. So it’s at least plausible that water will always sink at the same temperature, or perhaps less absolutely, the sinking temperature might be stabilized by this factor. However, it might sink at a different place if cooling is slower.
That latter idea seems consistent with what’s been happening in the arctic, where the position of recent decades ice loss appears generally consistent with the gulf stream currents getting further north, possibly as it cools slower in warmer temperatures.
R.
Nice simplified illustrations, Willis. As to the hiatus/pause, the number of papers attempting to explain it away now exceeds fifty according to Anthony. They each do it in their own way and obviously they can’t all be right. I love the ones that are looking for the lost heat in the ocean bottom. Don’t be surprised if despite what you said they will start quoting you out of context on that. The existence of the hiatus is what is being questioned but these people don’t even know about the other hiatus in the eighties and nineties that is being covered up by fake warming. It lasted 18 years, same as the current hiatus today. I discovered this when doing research for my book and it is shown as figure 15 in it. The false warming covering it up has been called “late twentieth century warming” and is one of the mainstays of their global warming argument. I don’t have good data on the fifties and sixties but there is a possibility of yet another hiatus from the fifties to the seventies. If we accept this it would make the entire global temperature curve from the fifties till the present a series of three hiatus platforms where no warming takes place. They would be connected with one another by short step warming periods that raise the global temperature just before a new hiatus begins. The last such step warming started in 1999, raised global temperature by a third of a degree Celsius, and then stopped in 2002. That established the temperature level for the current hiatus platform. This, and not an imaginary greenhouse effect is what makes twenty-first century temperatures higher than the twentieth was. The previous step warming connection would have been about 1976 and would have raised global temperature to the level of the eighties and nineties hiatus/pause. But that is not the global temperature history we are taught by the wise men of IPCC. Goes to show that high pay for climate “scientists” results in low quality temperature history.
The Arctic does not have a land mass underlying it like the Antarctic does. It would seem that this is another major factor that determines water circulation and may partially explain why the Antarctic stores more water (as ice) than the Arctic.
The south pole is around 2,700 meters (~9,000 ft) above sea level whereas the North pole is around 0 metres (0 ft) above sea level.
Willis,
You do an excellent job of provoking thought and discussion with your seemingly simple forays of musings. Please keep it up, generally. 😉
Rert,
“When does the water sink? When it’s denser than the water below.”
So when does the water near the bottom rise? When it is less dense than the water above. So the water both rises and sinks in the same place. That is convective mixing. A difference in density between the top and bottom does not produce a net flow in either direction.
There is a net flow downward when water is flowing towards the area at the surface and away at depth. It is the horizontal flows that cause the vertical flows. There are two factors that contribute: winds push around the water at the surface and pressure differences (due to difference in average density in the water column) push around the water at depth. The wind is the larger effect; which is why oceanographers usually do not use the term thermohaline circulation. They call it the meridional overturning circulation or just MOC.
“When it reaches 4 C it will be, because that’s the temperature at which the density of water is an absolute maximum”.
That is the case for pure water. It is irrelevant for the ocean. The density of seawater decreases as temperature rises for all temperatures.
Not so fast Mike, the curve changes, but there is still a “hump”, above the freezing point.
See charts I posted above.
Thanks both for this, both make sense. The effect of salinity changes on density profile was news to me,
The point I was floundering to make properly was that there is no guarantee that the descending water in an ocean circulation will be warmer, just because surface conditions are warmer. The pattern of circulation might compensate, and that seems consistent with the sea ice movements in the Arctic, particularly around the NE extreme of the Gulf stream.
So though I think Willis’s post is a very interesting insight, my comment was that it is (obviously) much more complicated than that.
Willis wrote” “Well, if the water that is descending at the poles is slightly warmer than in the past, then there will be less cold water added to the bottom of the ocean. With less cold water added to the bottom, on average the ocean depths would warm slightly compared to the past … and the interesting point is, the ocean would warm from the bottom up.”
I find this confusing and it seems like others do too. I think a better description is the following.
Over most of the planet, the surface ocean is much warmer than the deep ocean. So there must be a flow of heat from the surface to the deep. Since the deep ocean stays cold, there must be a return flow of heat to the surface. That can only happen in places where the surface is colder than the deep. If you now warm the surface water slightly in those places, there is less return of heat to the surface. So the deep will start getting warmer. Then the flow of heat down over most of the ocean starts to decrease, and the flow up in the cold surface regions starts to increase until a new balance is established.
I’m just really glad ice floats or we wouldn’t even be here.
The ocean floor is about a half mile thick, or thin, depending on your point of view. Not much heat resistance between the hot core and deep ocean.
Nickreality,
I think you need to brush up on oceanic crust. It is generally less than 10 km, but not uniform, and as thin as you say is rare.
Oceanic Crust:
“Composition[edit]
Although a complete section of oceanic crust has not yet been drilled, geologists have several pieces of evidence that help them understand the ocean floor. Estimations of composition are based on analyses of ophiolites (sections of oceanic crust that are preserved on the continents), comparisons of the seismic structure of the oceanic crust with laboratory determinations of seismic velocities in known rock types, and samples recovered from the ocean floor by submersibles, dredging (especially from ridge crests and fracture zones) and drilling. Oceanic crust is significantly simpler than continental crust and generally can be divided in three layers.
Layer 1 is on an average 0.4 km thick. It consists of unconsolidated or semiconsolidated sediments, usually thin or even not present near the mid-ocean ridges but thickens farther away from the ridge. Near the continental margins sediment is terrigenous, meaning derived from the land, unlike deep sea sediments which are made of tiny shells of marine organisms, usually calcareous and siliceous, or it can be made of volcanic ash and terrigenous sediments transported by turbidity currents.[3]
Layer 2 could be divided into two parts: layer 2A – 0.5 km thick uppermost volcanic layer of glassy to finely crystalline basalt usually in the form of pillow basalt, and layer 2B – 1.5 km thick layer composed of diabase dikes.
Layer 3 is formed by slow cooling of magma beneath the surface and consists of coarse grained gabbros and cumulate ultramafic rocks. It constitutes over two-thirds of oceanic crust volume with almost 5 km thickness.”
http://en.wikipedia.org/wiki/Oceanic_crust
Check, just a little exaggeration. 7.5 km +/-. The continental crust ranges from 30 to 50 km (3,200 ft/km +/-). Guess which crust will transfer the most heat easiest and fastest. My point is that ocean floor geothermal heat flux could be pumping gazillion Btu’s into the ocean, venting CO2, raising the temperature slightly (that’s a lot of water at 1 Btu/lb-F) and outgassing CO2. IPCC admits not knowing below 2,000 meters which is half the ocean. Pretty extensive “Don’t know!”
Yes, I hear you.
It has been opined that we know more about the surface of the moon than we do about the deep ocean.
I was going to comment on this part of the discussion, but it seems that everyone has left.
The gist of the point I was going to make is just that some of the commenters seems to overlook a few things in some of their comments. No big deal, we all do, and this stuff gets complicated, so a lot to keep in mind.
One is that thermal stratification of water is inherently very stable, as the cold water is more dense, and so can only rise is either heat is added, of if colder water descends and forces some of the bottom water to rise.
From what I have been able to determine over the past few days, it seems that the upward leg of the thermohaline circulation is thought to be much more diffuse than the places where very dense water forms and descends to depth. It seems there may be no upwards currents, just a very spread out upward movement over large areas as new dense water descends.
Also overlooked is that parcels of water with a certain temp and density will resist mixing with parcels that have different characteristics.
Regarding heat from the earth warming the bottom water, it seems to me we need to get some good data on the rate of thermal flux from below, and how much of an effect this has.
I wonder if the rocks and sediment at the bottom may still be warming up after being cooled by the ice age ocean for tens of thousands of years.
Consider that even a small pond retains winter cold water at the bottom all Summer, and even after the bottom water warms, the sediment and rock underneath the bottom water will only then begin to warm.
Where is the no-return valve in the oceans? So why doesn’t the heat flow reverse towards the equator, equalising in and out heat transfer? So why should the oceans heat up?
Ken Mourin
Is it true that as the area of Antarctic sea ice grows the area of under ice melting, increasing the volume of cold dense South Polar water that flows northward? This increased cold water volume must have an effect on climate over time in noth north and south hemisphere. Or, so it seems logical to me.
Willis, there is a substantial difference between the systems shown in Fig. 1. &. 3. respectively. In the thermosyphon the solar collector is at a lower elevation than the water tank. On the other hand, in the climate system sea surface is at the same gravitational potential at both tropics and poles. Therefore in the latter case no thermodynamically driven overturning is possible. Or, because solar radiation penetrates into the ocean a bit, it would be a very shallow overturning cell, not at all akin to the complete in-depth overturning observed. True, geothermal heating happens at the bottom, but that only accounts for a negligible fraction of fluxes measured in meridional overturning circulation.
The reason MOC still works is the complete lack of cost effectiveness in its design. Unlike in case of a thermosyphon, it does require a pump to run it. The pump is called deep turbulent mixing and it is a process driven by pure mechanical energy input, that is, energy at a low entropy, which has nothing to do with thermodynamics. It is provided by winds and tides. They generate internal waves in the bulk of oceans, which eventually break at specific sites like rugged bottom features or continental margins of complex geometry, resulting in vigorous turbulence and mixing different oceanic layers together. In doing so it replenishes buoyancy to the abyss by mixing some warmer/fresher water downward.
That’s a critical step. Without it eventually the abyss would get saturated with dense, cold water of high salinity and downwelling in polar regions would grind to a crawl. Neither geothermal heat flux acting at the bottom is powerful enough to change that, nor thermal conductivity of seawater is high enough to transport heat downwards anywhere close to the required rate. And diffusivity of salts is even less than that, by some two orders of magnitude.
In a world with neither tides nor winds, the deep ocean is locked in a stale state and becomes anoxic eventually, with next to no overturning whatsoever. The mechanical energy input driving deep turbulent mixing may be minuscule compared to the huge amount of heat moved around, still, it is indispensable to keep the engine running.
Even rate of vertical turbulent mixing is measured to be far too small over much of the open ocean to do the job, it really happens at poorly known specific sites, intermittently, when this rate increases by several orders of magnitude locally, for a while. And no, there is no such thing as “upwelling”, ever. There is no power on Earth that could raise a dense, cold, salty, undisturbed water parcel to the surface against the gravitational gradient.
The energy needed to run this pump is provided by tides and winds on a roughly fifty-fifty bases. One needs a full exeligmos (54 years &. 33 days) to have a similar tidal configuration over any specific region and winds clearly have an annual cycle, so the pump does run in a somewhat haphazard way. By the way, most of vertical turbulent mixing (about 80% of it) happens in the Southern ocean, so that’s the engine behind the Great Conveyor Belt, not temperature or salinity differences.
Seawater is a curious substance, it is very different from freshwater indeed. As everyone knows density of pure water is highest around 4 degrees centigrade, that is, well above freezing. That’s why overturning happens during the fall and spring seasons in lakes at temperate regions and stops in the winter, because liquid water next to the water/ice interface is too light to go down. However, seawater is not like that in this respect. At high enough salinity density of water is highest just above freezing, so a water parcel only has a chance to go down if it is close to the ice/water interface, which holds for the entire ocean except for some brackish pockets and marginal seas. It is exacerbated by the phenomenon of brine exclusion, that is, as ice crystals do not like salts very much, upon partial freezing the salinity of the liquid phase increases and with that its density as well.
Now, the pump may operate far away from the poles, but as it makes room in the abyss for dense parcels to sink by replenishing buoyancy there, the sites where actual downwelling would occur are those where density of seawater is highest. According to the previous paragraph, it is somewhere along the ice margin. The density is influenced by two factors, temperature and salinity.
In the downwelling region surface temperature is determined by the physical properties of water, not climate, at least until the ice margin is gone entirely, which, under the current configuration of continents, is not projected even by the wildest cAGW scenarios. It is the exact location of the ice margin, which is influenced by climate, but that’s another topic.
However, that’s only true at atmospheric pressure, that is, close to the surface. With increasing pressure freezing point of seawater decreases. If the ice/water interface goes down to some depth, as it does around Antarctica, but not in the Arctic, temperature of liquid water next to the ice can decrease well below its freezing point on the surface, and with that increases its density. Therefore water parcels of the highest density are formed in a different way around the two poles. Salinity of Antarctic bottom water is somewhat less than that of North Atlantic deep water, but its temperature is lower and with that its density is a bit higher. When the two water masses meet at the bottom somewhere around the equator, Norh atlantic deep water forms a layer above Antarctic bottom water.
In another geologic epoch, when polar regions were covered by open ocean and there was no ice/water interface whatsoever, deep water formation worked in an entirely different way. Then water masses of the highest salinity went down at the horse latitudes, where evaporation exceeds precipitation by a wide margin. It made abyssal temperatures much higher, around 20 centigrade, as opposed to 3 today. It still happens in marginal seas like the Red sea or restricted areas of the Caribbean, but it is not a dominant process and can only form intermediate water masses.
In some other marginal seas, like the Black sea, there is an ice margin in the winter at the Northern edge, but surface waters are much too brackish to sink into the salt water below, which forms a stable anoxic mass, with much dissolved methane and highly toxic hydrogen sulfide in it.
The upshot is temperature, and with it heat content of deep waters is not regulated by climate, but by physical properties of seawater and configuration of continents. Heat content can only increase, if salinity also increases with it, which means an increasing ratio of North Atlantic deep water relative to Antarctic bottom water. I do not think this is what’s happening.
All those words and he has never heard of the earths rotation!!!!!!!!!!!!!!!!!!!
Berenyi, I think you may underestimate the pumping capacity of the Antarctic vortex. This whirling dervish accelerates both air and water north of it from at least the troposphere to the abyssal ocean. It is this pump that renders what would otherwise be meridional overturning a truely global thermohaline circulation.
Your points that thermal/density are wildly insufficient to drive this circulation as a heat engine are well taken.
I love that we’re talking thermal and solar
If we are going to measure the Earth’s temperature, should it be measured in the overflow at the Denmark Straights gap? Isn’t everything else just weather.
It’s about time that readers of WUWT get wised up, that oceanic waters (containing salts) DOES NOT have it’s maximum density at 4 deg. C
The data is readily available on line the average ocean salinity is about three times as much as the salinity needed to guarantee that sea water continues to increase in density right up to the point where it freezes, which is somewhat colder than zero deg. C
Pure fresh water has its maximum density at 4 deg C but salt water does not.
Sea water contains about 3-4% of dissolved salts.
For salt water containing more than about 1.5% (as I recall), the density increases right down to the freezing Temperature which is sub zero.
This drum has been beaten here at WUWT for years, as it is a key issue in climate effects and the freezing cycle of water.
So let’s not hear any more of this 4 deg. C stuff.
Yes it is the cause of the turnover of fresh water lakes, but it doesn’t turn over the ocean.
Mr. Smith,
Got any references to back that up?
I have only recently begun to look at this closely, but it seems to not be just as you describe either:
http://linkingweatherandclimate.com/ocean/figs/density2.png
Mr. Smith,
Never mind that last question. I see that you are correct. I was misreading what the chart seemed to be indicating.
24 pcu seems to be the critical level, and sea water is usually 35 or more pcu.
Good on ya!
Here is a simple graph that sums it nicely:
http://www.fondriest.com/environmental-measurements/wp-content/uploads/2014/01/360x300xwatertemp_salinity.jpg.pagespeed.ic.yheIMC6nSN.jpg
The heat capacity of the ocean is 1000 times that of the atmosphere. If we have lost, say 1 degree C of warming into the oceans, we can only expect the ocean to warm by 0.001 C. It seems to me that if the heat is getting lost in the ocean we do not have to worry about it, the global warming “problem” is solved.
I had thought that if some people are saying that all the missing heat is going into the oceans, what that means is that some people are running out of excuses.
I’d go for 4 times, Water at 1 Btu/lb-F opposed to air at 0.24 Btu/lb – F. The latent heat of evaporation/condensation is worth 950 to 1,000 Btu/lb depending on some details.
nickreality65 – we are talking about separate things. You are comparing heat capacity of a lb of air to a lb of water. I am comparing heat capacity of the ocean to heat capacity of the atmosphere.