Guest Post by Willis Eschenbach
According to the current climate paradigm, if the forcing (total downwelling energy) increases, a combination of two things happens. Some of the additional incoming energy (forcing) goes into heating the surface, and some goes into heating the ocean. Lately there’s been much furor about what the Levitus ocean data says about how much energy has gone into heating the ocean, from the surface down to 2000 metres depth. I discussed some of these issues in The Layers of Meaning in Levitus.
I find this furor somewhat curious, in that the trends and variations in the heat content of the global 0-2000 metre layer of the ocean are so small. The size is disguised by the use of units of 10^22 joules of energy … not an easy one to wrap my head around. So what I’ve done is I’ve looked at the annual change in heat content of the upper ocean (0-2000m). Then I’ve calculated the global forcing (in watts per square metre, written here as “W/m2”) that would be necessary to move that much heat into or out of the ocean. Figure 1 gives the results, where heat going into the ocean is shown as a positive forcing, and heat coming out as a negative forcing.
Figure 1. Annual heat into/out of the ocean, in units of watts per square metre.
I found several things to be interesting about the energy that’s gone into or come out of the ocean on an annual basis.
The first one is how small the average value of the forcing actually is. On average, little energy is going into the ocean, only two-tenths of a watt per square metre. In a world where the 24/7 average downwelling energy is about half a kilowatt per square metre, that’s tiny, lost in the noise. Nor does it portend much heating “in the pipeline”, whatever that may mean.
The second is that neither the average forcing, nor the trend in that forcing, are significantly different from zero. It’s somewhat of a surprise.
The third is that in addition to the mean not being significantly different from zero, only a few of the individual years have a forcing that is distinguishable from zero.
Those were a surprise because with all of the hollering about Trenberth’s missing heat and the Levitus ocean data, I’d expected to find that we could tell something from the Levitus’s numbers.
But unfortunately, there’s still way too much uncertainty to even tell if either the mean or the trend of the energy going into the ocean are different from zero … kinda limits our options when it comes to drawing conclusions.
w.
DATA: Ocean temperature figures are from NOAA, my spreadsheet is here.
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@ur momisugly Eco-geek 5:55 am
Your analogy with radiant space heaters fails due the the vast difference of relative temperatures. Radiant heaters operate at 400 – 900 deg C, our earth is circa 30 deg C.
The Stefan–Boltzmann law is proportional to the fourth power of the temperature T.
The size is disguised by the use of units of 10^22 joules of energy … not an easy one to wrap my head around.
I agree. So let’s wrap it up.
Convert all such figures in 10^22 Joules into ZetaJoules, 10^21 Joules.
(Note, these are the units of the SkS graph above… those exponents are fine print)
Now keep these earth constants in your back pocket:
Heat to raise upper 0-2000m Ocean 1 deg K = 2730 ZJ / deg K
Heat to raise 0-700m Ocean 1 deg K = 960 ZJ/K
So the SkS graph’s Y-Axis of 0 to 200 ZJ could be replaced with 0 to 0.07 deg K.
On top of that, the X-Axis runs from 1950 to 2003… stopping before the ARGO constellation. Today, with ARGO, it is debatable whether we have precision of 0.05 deg K. Before ARGO, it is fantasy to suppose we measured the average temperature of the 0-2000m ocean layer to even 0.25 deg K. So the entire SkS graph is well within reasonable error bars.
So, whenever you see x.x*10^22 Joules,
immediately convert it to temperature at the rate of 2730 ZJ per deg K
Interesting,
What you are calculating is the net heat flux into the ocean that is causing it to warm. I don’t understand why you are surprised that the calculated amount of extra warming is so small (on the scale of < 1 Watt per m^2. The ocean is a pretty big place.
compare this additional heating with the ACTUAL energy balance of the oceans, where MASSIVE amounts of heat energy are absorbed in the tropics and carried to the higher latitudes by currents where it gives off its heat energy to the atmosphere:
http://oceanworld.tamu.edu/resources/ocng_textbook/chapter05/Images/Fig5-7.htm
The tropical net energy absorbed in the latitudes of -30 to +30 is about 40 Watts per meter squared on average.
Anthony Watts says:
June 19, 2013 at 4:13 am
Hmmm, this rather puts the kibosh on this graph from the SkS zealots
…
Makes me wonder how Murphy finds such a large trend in OHC, but Levitus does not find any trend in forcing.
_______________________
If you draw a corresponding graph using data in Willis’ sheet (the Joules column) you get very similar, compatible result. That actually ensures me the Willis’ analysis is about right.
What’s missing are uncertainity intervals but I don’t think they would change much as individual errors cancel out. There is no dispute that there’s about 0.07 between -0.013+/-0.006 and 0.061+/-0.002, you can’t bring that down to zero by saying that the forcing is statistically indistinguishable from zero as demonstrated in this article. And that’s the answer to your question.
I like this article. It puts those huge OHC numbers nicely in context.
Recall that Trenberth is looking for 0.58 W/m2 (“missing”) he can’t account for in his energy balance of the planet, which infers that he believes he has something like 0.29 W/m2 of +/- in his work (sig:noise ratio = 2.0).
So the see a value of 0.2 +/- 0.3 W/m2 of oceanic heating, with a trend of 0.1 W/m2 per DECADE, +/-0.2 W/m2. Hmm.
We need to review what Trenberth is claiming: he is “missing” 3 times what you see, with a probable error of about the same.
Something doesn’t jive and I bet I know what: Trenberth’s missing heat is the reductive product of all sorts of calculations and measurements (not the same) that have been systemically cleaned of error bars.
I don’t believe on first principles that we know or can know the energy balance of the Earth to such fine points as Trenberth must believe to do his work.
I find it hard to believe anyone can say, with any degree of certainty, just what the average temperature of the oceans on this planet is. The Pacific and Atlantic oceans alone are so vast, with currents constantly changing, and upwellings and downwellings occurring constantly somewhere at all times, there are not enough static temperature monitors at all the various depths to adequately measure and compile data.
Willis,
interesting article, I was able to read your other study on the missing heat here:
http://wattsupwiththat.com/2013/05/10/the-layers-of-meaning-in-levitus/
where you said,
“I’d say not particularly. Yes, the middle layer (100-700 m) started warming in 1995. And yes, the lower layer (700-2000 m) followed suit starting in about 2001. But neither of these seem particularly surprising. I don’t have any explanation for them, but they do not seem to be unusual. It is possible, for example, that they represent the sub-surface changes associated with the gradual shift of the Pacific Decadal Oscillation from the positive to the negative phase. ”
————–
I wanted to let you know that this is EXACTLY what is going on and it shows that a very small (almost imperceptible amount) of extra heating is going into the deeper ocean when the PDO turns negative.)
The net energy flux in the tropics is still quite large and positive (see post above) but the amount is only very slightly more or less positive.
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The reason that this is significant is that the amount of heat energy going into the tropics is SO LARGE that only a very small change in the amount of heat absorbed in this region can produce massive changes (heating and cooling) in the atmosphere.
———————-
This is why we have had a “stagnation” of warming since 1998.
The interesting (bizarre) part of their argument requires that the energy flux at the surface has to be orders of magnitude higher in the areas where there is downwelling.
Given that the “missing heat” is not stored in the upper layers of the oceans. Given that the “missing heat” is warming the deep oceans. Given that the “missing heat” travels to the deep ocean by downwelling. Given that the areas of the oceans where downwelling occurs is something like 1% of the entire area of the oceans. Given that the volume of the deep oceans is so vast that the “missing heat” raises its temperature by fractions of a degree.
This can only mean the “missing heat” is discretely added to the downwelling water just when it becomes too late to measure.its temperature.
I recall reading that it takes over 800 years for surface waters to permiate down to the deep ocean. If true, any energy increase we may (or may not) be seeing is from the MWP.
Here’s a reality check. For ease of arithmetic, let’s suppose that a 1M x 1M x 200M water column is absorbing 1 Watt every hour of every day for a whole year. If we convert that to calories we get: 5363190 cal.
There are 100 x 100 x 200 x 100 grams of water in the column. Since one calorie causes one gram of water to warm by one degree centigrade, we divide the calories by the grams to get a net heating of 0.027 degrees centigrade per year.
So, if the ocean were a uniform 200 M deep and if it absorbed 1 watt per square meter (of surface) 24 hours a day for 100 years, it would warm up almost THREE whole degrees. That’s the worst case if you make a couple of unsupportable assumptions.
I have no idea how fast heat moves vertically in the ocean but its average depth is around 4000 meters. If the heat were uniformly distributed then the warming would be closer to 0.15 degrees C per century. If we choose a more sensible value for the watts per square meter, then the heating is even less.
As others have pointed out, the warming of the ocean is so tiny that we can’t even measure it from year to year. That’s why the alarmists give us values in gigajoules. It sounds way scarier.
With the accumulated “coolth” from an entire ice age, the deep oceans are colder than a penguins armpit. The last thing we want is that cold water coming up to trouble an unhappy world.
Claiming that that’s where all the global warming has gone is, perhaps, the most honourable exit that can be found for the IPCC.
I am on the hunt for some historical census of deep ocean temperature data: How much by time. I found this curious paragraph describing what appears to be the MiniMODE experimental system from the early 1970s :
These floats were short range so the data is clumpy and the recordings very primative.
Whatever you thought the error bars were on OHC prior to 1970…. double it.
Willis, is it me or is this a typo:
“…from the surface down to 200 metres depth.”
2000 metres, right?
It divides commiebob’s calculated result by 10.
[Thanks, fixed. w.]
My mistake on this comment, Bob T
Willis: Sorry to say, I get different results. But mine show annual changes that are significantly less than yours. Your variations range from about -2.2 to +2.2 watts/m^2, while mine range from -0.06 to +0.06 watts/m^2.I started with the annual NODC vertically averaged temperature data for 0-2000 meters:
http://data.nodc.noaa.gov/woa/DATA_ANALYSIS/3M_HEAT_CONTENT/DATA/basin/pentad_mt/pent_T-dC-w0-2000m.dat
I then created a graph of the annual changes in temperature, and the wiggles matched your graph:
http://i42.tinypic.com/347d1xl.jpg
In their Table S1 of Levitus et al (2012), the NODC provides the relationship between the changes in Heat Storage and Vertically Averaged Temperature. See page 22 of pdf.
http://data.nodc.noaa.gov/woa/PUBLICATIONS/grlheat12.pdf
Based on linear trends, for the period of 1955 to 2010, they claim heat storage increased 0.39 watts/m^2, while the vertically average temperature rose 0.09 deg C, both based on the pentadal data of course. That gives a multiplier of 4.333 watts/m^2 per deg C.
If I then apply that multiplier to the above changes in vertically average temperatures, I have the change in heat storage in watts/m^2.
http://i41.tinypic.com/2la67hj.jpg
@Joe Kirklin Public
Pedantic correction:
“The Stefan–Boltzmann law is proportional to the fourth power of the temperature T.”
“…where T is expressed in degrees Kelvin.” I am adding this because you cited °C in the previous sentence.
Very nice, Willis.
I’ve seen this depth of penetration argument made a numnber of times. Beware of it because it is false.
Just think about the day night temperature cycle over the ocean. During the day SWR heats the ocean. And at night it cools back down again mostly by radiating LWR to the sky. The amount of heat that it loses at night by radiating LWR is approximately equal to the amount gained during the day by absorbing SWR – else the oceans would have boiled by now.
It is true that since LWR is strongly absorbed by water, only the top couple of millimeters can absorb or emit LWR. This means only a thin skin on the surface cools at night. But this cooled surface layer then sinks and warmer water from deeper down rises to the surface and is cooled in turn. This overturning process goes on all night. Night time cooling due to LWR moves almost as much heat out of the water as the sun put into it during the day via SWR (some heat is also lost to evaporation).
Now consider what happens if there is backscattered LWR at night from clouds or from CO2. The sky appears ‘less cold’ – as can be seen by pointing a thermometer at it – because of the backscattered LWR. The result is that on cloudy nights the surface of the water cools less quickly as the backscattered LWR counterbalances some of the emitted LWR and slows the cooling process.
Net warming of the oceans over a period of time can be achieved in two ways. By increasing the SWR energy absorbed during the day, or by increasing the backscattered LWR to slow cooling at night. Both processes move a similar amount of heat. The fact that only the top millimeter of water can radiate LWR doesn’t prevent a lot of heat moving into and out of water via LWR so long as overturning is mixing the layers near the surface, which happens every night.
Don’t get fooled by the depth of penetration argument. The reason you can’t heat water from above efficiently with a heat lamp is simply because convection would need to run in reverse to mix the heat into the lower layers. So long as convection is running in the right direction an IR lamp can transmit heat into water quite effectively. To warm water from above with an IR lamp all you need to do is stir.
Indeed it is. The 0.3° doubling sensitivity matches my own long-time estimates, so it must be right! 🙂
Self-contradictory, incoherent, patent nonsense. Convection blocks heat penetration. Duh.
Where does the energy come from to do the “stirring”? The work cost to the oceanic heat engine zeroes-out the counter-convection deep heating. TANSTAAFL
Kristian says June 19, 2013 at 5:57 am “It’s important to note that ‘downwelling energy’ to Earth’s surface from above does and can not ‘heat’ the surface unless it comes down as … heat.”
Energy is the ability to do work, whether it is to move an object or to heat an object. Radiated energy becomes heat, electrical energy (solar cells) or chemical energy (photosynthesis) when it is absorbed.
“To warm water from above with an IR lamp all you need to do is stir.”
I don’t think so.
Movement of the water increases surface area which increases evaporation which is a powerfully net cooling process.
Surface molecules receiving downward IR do not get warmer and sink. They simply evaporate sooner than they otherwise would have done and stirring makes it happen even sooner. In the process of evaporating all the energy from downward IR disappears into latent heat for no net slowing of the background rate of energy transfer from water to air.
I went into it all in tiresome detail some time ago, here:
http://climaterealists.com/index.php?id=7798
“The Setting And Maintaining Of Earth’s Equilibrium Temperature “
science is settled
jai mitchell says:
June 19, 2013 at 7:48 am
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I have not checked your figures, but they could be correct. All that extra net energy is from Solar.
There is so much excess Solar going into the tropical ocean that it will never freeze. This excess heat/energy is then distributed polewards which in turn prevents the oceans at higher latitudes freezing. It is only tjose at the very highest latitude that don’t receive enough Solar and distributed heat energy emanating from warm currents from the tropics that freeze, or freeze seasonally.
DWLWIR is not needed at all to explain why the oceans do not freeze (a point that Willis does not appear to appreciate). Which is obvious given that about 60% of LWIR is absorbed within the first 2 or 3 microns (not millimeters) where the heat flux is upward such that energy absorbed in the first 2 or 3 microns cannot be sequestered to depth and simply drives surface evaporation. and all but no LWIR penetrates beyond about 15 microns 9where the heat flux still operates upwards).
Nice post Willis. In a much earlier post on this site you made the assertion that the behavior of the ocean and atmosphere above it (what I now think of as the rest of the ocean of water on our blue ball) was the “governor” regulating the temperature on the planet. I agreed with that insightful thinking and now even postulated further on it. (For this response think of the “ocean” as encompassing ALL of the water on the planet, from the bottom of the liquid ocean to the top of the atmosphere where water has crystalized into ice particles.)
I would like to add to the theory in your earlier post, something that I observed later on in a different post here on WUWT. During the time that hurricane Sandy was making a big splash in the news, someone posted a picture of what the storm looked like in the infrared part of the spectrum from outer space – at night, no moon! Now unless the storm was actually giving off infrared light, that picture should have been all black. But what you could clearly see was that different layers of the storm were giving off different amounts of light. So I assert that what was missing from your original post is that at the three different layers in the ocean/atmosphere where phase change occurs – ie. where massive amounts of energy get dumped into the liquid ocean to create water vapor, then at the layer where that vapor condenses back out of the atmosphere, and then again at the top layer where the liquid crystalizes to form ice – you should see in infrared images (especially in the IR spectrum where water has a high extinction coefficient) where water appears to be “glowing”. That IR “picture” is a dynamic rebalancing of the radiative energy equation. Radiative energy being transmitted off of our blue ball is not a static “average” thing. It is as dynamic as solar storms are, and water is the primary molecule that absorbs then moves then condenses and transfers the energy off of the surface of the ocean back to the cold of outer space.
Combining radiative losses from the background IR glowing from storms with the HUGE radiative loss every time lightening occurs and you have the last piece of the dynamic energy balance that is happening every day at all locations on this planet. Any excess energy from the sun that warms up the ocean, causes water to evaporate, carrying that energy into the lower layer of the atmosphere. Now that layer continues to absorb light and along with continuing evaporation lifts the water vapor up vertically until the elevation where the temp/press matches dew point at which point condensation releases some of the energy radiatively back to space and also coincidentally creates a white billowy cloud that now scatters sunlight back to space preventing the ocean below from absorbing any more energy. If the condensed water vapor continues to absorb excess energy from the sun and is fed more water vapor from below the white billowy cloud climbs higher and higher until it reaches the height where the temp/press match the freezing point and a second phase change occurs. Both phase changes AND the active transport of energy off of the liquid oceans surface up to the highest level of the atmospheric ocean create a “self regulating” system that CAN NOT exceed the boundaries water’s natural temp/press/phase properties place on it.
This “model” is still too simplistic because in any storm, a massive amount of energy is consumed in the work of transporting huge volumes of water across vast expanses of ocean or land, and the energy expended in a storm can get extreme! No one can really predict the violence that results. Chaos!
In a self regulating system that at any point in time or space has temperature varying from a warm 80 degrees all the way up to 0 degrees where ice has formed, again what is the point of fixating on “average” temperature variation of 1 degree over a day, month or year? or trivial fluctuations in average energy content that is more than likely noise? Why is everyone paying so much attention to our self regulating system’s noise that is most likely error in measurement anyways?
Jeff Norman
when you said,
The interesting (bizarre) part of their argument requires that the energy flux at the surface has to be orders of magnitude higher in the areas where there is downwelling.
————
This isn’t really true at all, in the tropics where the heat is absorbed by the ocean only a very small change in the mixing/efficiency of heat energy transported into the deeper waters would produce the measured warming in this article.
maybe about 1.2% increased absorption in the tropics would do it. See the following graphic.
http://oceanworld.tamu.edu/resources/ocng_textbook/chapter05/Images/Fig5-7.htm
The tropical net energy absorbed in the latitudes of -30 to +30 is about 40 Watts per meter squared on average.