Introduction To The NODC Ocean Heat Content Anomaly Data For Depths Of 0-2000 Meters
The National Oceanographic Data Center (NODC) recently posted a new Ocean Heat Content (OHC) anomaly dataset on its website. It is available on annual and quarterlybases, along with the data for its standard and documented dataset that covers depths of 0-700 meters. I looked for but was not able to find any papers (in any state of publication) that supported the new OHC data for 0-2000 meters. We’ll just have to wait and see how the NODC intends to present this dataset.
The data for the depths of 0-700 meters is, of course, documented in the paper Levitus et al (2009) “Global ocean heat content (1955-2008) in light of recent instrumentation problems”. Refer to Manuscript. It was revised in 2010 as noted in the October 18, 2010 post Update And Changes To NODC Ocean Heat Content Data. As described in the NODC’s explanation of ocean heat content (OHC) data changes, the changes result from “data additions and data quality control,” from a switch in base climatology, and from revised Expendable Bathythermograph (XBT) bias calculations.
COMPARISON OF GLOBAL OHC ANOMALIES: 0-700 METERS VERSUS 0-2000 METERS
Figure 1 compares the quarterly NODC OHC anomaly data for the depths of 0-700 meters and 0-2000 meters on a global basis. As noted on the illustration, the most obvious divergence between the two datasets occurs during the ARGO era. This is the period when ARGO floats became the dominant means of sampling of ocean temperatures and salinity at depth.
Figure 1
If we limit the comparison to the period from 1970 to 1999, Figure 2, we can see that there is basically no difference in the linear trends. There are minor differences from year to year, but the two datasets appear to be basically the same. Why?
Figure 2
There are extremely few observations prior to the year 2000 at depths greater than 1000 meters. This is illustrated in Figure 3. (Note that NOAA Climate Prediction Center Data Distributionwebpage breaks down the temperature profiles into depths of 0-250 meters, 250-500 meters, 500-1000 meters and 1000-5000 meters. Those depths don’t agree with the depths presented by the NODC for its Ocean Heat Content anomaly data.)
Figure 3
And Animation 1 shows a series of annual maps of the locations of temperature profiles from 1979 to 2005 for the depths 1000-5000 meters. As illustrated, there is also very little spatial coverage at these depths until the introduction of the ARGO floats.
Animation 1
As a reference, Figure 4 shows the number of temperature profiles for depths of 250 to 500 meters. There were between 2000 to 5000 temperature profiles per month between the late 1970s and the late 1990s at these depths before the ARGO floats were deployed. Note that the TAO/TRITON project (red curve) shows temperature profiles that were initially for the equatorial Pacific (coordinates approximately 8S-9N, 137E-95W). Those buoys were deployed for the study of El Niño and La Niña events. The locations were later expanded to include portions of the Tropical Atlantic and Indian Oceans under the PIRATA and RAMA projects. Refer to the TAO Project Global Arraywebpage. So while there are a good number of temperature profiles for the TAO project, they are limited in their location.
Figure 4
Figure 5 illustrates the difference between the two NODC Global Ocean Heat Content (OHC) datasets, where the 0-700 meter data has been subtracted from the 0-2000 meter data. Also referring back to Figure 3, the difference between the two datasets seems to increase in concert with the number of temperature samples at depths greater than 1000 meters. It appears as though the divergence of the 0-2000 meter dataset from the 0-700 meter data since around 2000 could be caused by the increased number of samples at depth and the increased spatial coverage of the ARGO floats, as shown in the animations. The impacts on short-term and long-term trends of the increased number of samples at depths greater than 700 meters and the impact of the increased area of observations should be determined. (A study such as that is well beyond my capabilities.) Maybe it will be documented in the NODC paper that accompanies the 0-2000 meter dataset.
Figure 5
Keep in mind, before the ARGO era, there were very few ocean temperature observations at any depth in the Southern Hemisphere south of about 40S. For example, Animation 2 is a gif animation of maps that illustrate the locations of temperature profiles for depths of 0-250 meters, 250-500 meters, 500-1000 meters, and 1000-5000 meters for the year 1995.
Animation 2
And Animation 3 shows the same series of temperature profile maps but for the year 2005.
Animation 3
A COUPLE OF QUESTIONS FOR READERS
Were the Expendable Bathythermograph (XBT) probes with wire lengths of 760 meters the most commonly used XBT probes before the ARGO era? Is this the reason the NODC originally limited the depth to 700 meters for the Ocean Heat Content anomaly data? Does anyone recall a paper that presents this? I had always assumed the depth of 700 meters was selected due to the number of and locations of observations, but I have never seen it stated in a paper.
LONG-TERM TRENDS PER OCEAN BASIN
When I originally prepared the graphs for this post, I could find no reason to present the long-term trends for the individual ocean basins of the 0-2000 meter data. The reason being, in some respects, the NODC OHC data for 0-2000 meters appears to me to simply be a 0-2000 meter OHC dataset spliced onto a 0-700 meter dataset. But on further thought, my failure to present the data might be thought by some as an attempt on my part to hide something. So Figure 6 (0-2000 meters) and Figure 7 (0-700 meters) are long-term trend comparisons of the Ocean Heat Content anomalies for the individual ocean basins as presented by the NODC. The most obvious similarity is that the long-term trends of the North Atlantic Ocean Heat Content are significantly higher than other ocean basins in both datasets, and in both, the North Atlantic Ocean Heat Content peaked in 2004. After that, there are significant declines. One would think this would lead researchers to examine the effects of the Atlantic Multidecadal Oscillation and Meridional Overturning Circulation on North Atlantic Ocean Heat Content observational data, yet, as far as I know, this is an area unexplored by climate scientists.
Figure 6
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Figure 7
ARGO-ERA TRENDS PER OCEAN BASIN
The ARGO-era (2003 to present) linear trends per ocean basin for the depths of 0-2000 meters and 0-700 meters are shown in Figure 8 and 9, respectively. Like the trends for the 0-700 meter data, the South Atlantic and Indian Ocean are the only basins with significantly positive linear trends for the 0-2000 meter Ocean Heat Content data. And also like the trends 0-700 meter data, the linear trends of the 0-2000 meter Ocean Heat Content anomalies in the North Atlantic and South Pacific are negative. The linear trends for those two ocean basins are less negative for 0-2000 meter depths than they are for 0-700 meter depths, indicating that the declines at depths of 0-700 meters are greater than the increases at the 700-2000 meter depths. Considering there is less than a decade of ARGO-era data with “full” coverage, there is no need to speculate about the cause. Note also that the trend for the North Pacific OHC anomalies is basically flat for the 0-2000 meter data, and that the same holds true for the 0-700 meter data.
Figure 8
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Figure 9
CLOSING COMMENTS
The undocumented (as of this writing) NODC 0-2000 meter Ocean Heat Content dataset appears as though it was prepared to show that Global Ocean Heat Content continues to rise during the ARGO era, and that it is intended to counter the argument that Global Ocean Heat Content has flattened during the ARGO era as shown in the NODC 0-700 meter dataset.
Due to the extremely limited number of observations at depths of 1000-5000 meters (shown in Figure 3 and in the animations), the 0-2000 meter Ocean Heat Content dataset should be used with great caution. It appears to me to be an ARGO-era 0-2000 meter Ocean Heat Content dataset spliced onto a long-term 0-700 meter dataset. For this reason, I, personally, would not expend the effort to analyze the long-term (pre-ARGO era) 0-2000 meter NODC OHC data beyond what has been presented in this post.
Each time I see the claim (based on many assumptions) by anthropogenic global warming proponent scientists that the rise in ocean heat content at depth “will come back to haunt us” I wonder why those same scientists have not bothered to attempt to document how much of the rise in OHC from the 1970s to the early 2000s (0-700 meters) was caused by the deep oceans upwelling warmer anomalies from past decades, other than the fact that there’s no data for them to do so. Could they believe that multidecadal variability is limited to Sea Surface Temperatures and does not impact temperatures at depth? Or is their intent to have the unsuspecting public believe it?
Thanks, Anthony.
Obviously they are doing this to support the theory that the “heat has gone to the deep layers” nonsense that was proposed last month.
Thanks Bob, still reading, but thank you for “watching the pea”!
I’m not going to state deepest depths because that is classified but evey submarine has recorded depth v temp v position every hour on the hour ever since submarines became part of the world’s Navies. Watch keeping is what the Navy does best. The info is on record but probably not available….yet.
Thanks Bob.
Interesting. Forewarned is forearmed. Regardless, expect the NOAA press release and media blitz prior to Durban and AR5….
Talking of which, shouldn’t we be expecting GISS to announce their full=year 2011 temperature anomaly pretty soon? 😉
Anthony, could you change the color choices for the first two figures, they are not color blind friendly.
They are so similar (same color family, nearly the same gray tone) a person who is red green color blind cannot tell them apart visually. Different color families would be best, ie one of them blue for example.
Larry
So that’s where Trenberth’s missing heat went!
Given the amount of water, wouldn’t it be possible to park a lot of heat down there with an immeasurable temperature rise? I think I once worked out that if all the energy generated by man for 1 year went directly to the ocean we would be able to raise its temperature by ~10µK.
At what resolution do Argo floats measure temperature?
You have got to be effing kidding.
0-700 tracks 0-2,000 without fail, until it magically diverges *exactly* when needed to ‘find’ the missing heat?
Fabricating with impunity.
A COUPLE OF QUESTIONS FOR READERS
Were the Expendable Bathythermograph (XBT) probes with wire lengths of 760 meters the most commonly used XBT probes before the ARGO era? Is this the reason the NODC originally limited the depth to 700 meters for the Ocean Heat Content anomaly data? Does anyone recall a paper that presents this? I had always assumed the depth of 700 meters was selected due to the number of and locations of observations, but I have never seen it stated in a paper.
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I think I have read somewhere that it represents the depth at which the temperature profile flattens out. So the cable lengths are therefore dictated by this rather than the other way around.
Don’t know for sure.
So, the IPCC will soon be accusing Earth of sweeping the anthropogenic heat “under the rug”, so to speak?
Thanks Bob!
The undocumented (as of this writing) NODC 0-2000 meter Ocean Heat Content dataset appears as though it was prepared to show that Global Ocean Heat Content continues to rise during the ARGO era, and that it is intended to counter the argument that Global Ocean Heat Content has flattened during the ARGO era as shown in the NODC 0-700 meter dataset.
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So your saying the data or analysis is faked.
I thought it was to resolve known problems in the energy budget of the earth.
So here is my suggestion. Set up a study controlled by you and funded by the Koch brothers. This will prove that those Argo guys are incompetent frauds.
Record too short. Period. Basically meaningless.
I didn’t see heat energy converted to temperature in this post. So I attempted to do that on my own. Somebody please check my numbers. I get total ocean volume at 1.3E9 km3, which is 1.3E 18 m3, which in turn is 1.3E21 kg of water. The specific heat content of water is 1.8 kJ/kg*K. Therefore, the specific heat content of the oceans is 2.3E24 J/K. The biggest anomaly number I see in the paper is 4E22 J. This is .017 degrees C.
Either I did something wrong (like assume too big a volume because the deep ocean doesn’t get warmer) or somebody has a far different understanding of our ability to measure temperature.
There also appears to be some centering mischief going on. Notice how the first 15 – 20 years shows the 0-2000 m OHC anomaly is slightly below the 0-700 m anomaly. Where have we seen that before?
hotrod (Larry L): Sorry. Will blue and red work for you? I’ll change them at the cross post at my website for you as soon as you give me an okay.
Can you imagine a drug company trying to do this with a medication?
The CEO would be in front of Congress within 24 hours.
LazyTeenager says: “So your [sic] saying the data or analysis is faked…”
Your response to my post is nonsensical. Please advise where in it I stated or implied that the NODC OHC data at any depth has been faked. If you would have read the opening paragraph of the post, you would have noticed that I noted that the NODC published the data before the paper with: “I looked for but was not able to find any papers (in any state of publication) that supported the new OHC data for 0-2000 meters. We’ll just have to wait and see how the NODC intends to present this dataset.”
Take your nonsense elsewhere. You and your ilk bore me.
Yes that will work very well. Almost no one is colorblind to blue (only true black and white colorblind have issues with blue). Approximately 10% of the males of northern European heritage have some degree of red-green colorblindness. Color pairs which are very difficult for us to tell apart are reds and dark oranges, dark greens and dark browns, dark blues and purples, very pale greens and yellow etc.
I am almost completely blind to light shades of cyan, and have subdued sensitivity to red, so very dark reds or colors which have red in them if dark are easily confused.
Thanks for the change. I sometimes can sort these charts out with colorblind tools like “colorzilla” addon in firefox or “whatcolor” but it is a big pain to do that especially on small charts as it is hard to center the cursor over the color trace, and sometimes the color key in the chart is not really the exact same color as the traces in the chart.
Larry
1.0 Watt/m2 over the entire Earth over 1 year equals 1.61 10^22 joules.
1.0 Watt/m2 over a year absorbed in the Oceans would by 1.13 10^22 joules
Since there has been little surface warming in the Argo era, the extra forcing from GHGs/Human-made had to be going to be somewhere – either directly back into space, or into the oceans, or into ice sheet melt/land accumulation (estimated to be about 0.1 watts/m2).
The IPCC said that the direct GHG/Human-made forcing in 2007 was +1.6 Watts/m2 (and it would be a little bit higher in 2010).
So where did the extra 2.58 10^22 joules go in 2010?
—> 0.0 went into surface temperature warming.
—> 0.16 10^22 went into ice sheet melt/land accumulation
—> -0.05 10^22 went into the 0-700 metre ocean
—> 0.6 10^22 went into the 700-2000 metre ocean (according to the new data).
That leaves the Earth 1.87 10^22 joules short or about 1.16 watts/m2 short. Space anyone? The energy is still missing.
They need a graph of ocean heat content for AR5, i Guess, and the old one just wasnt “promoting the message” sufficiently…
Bob, outstanding work as always.
I suspect the Indian ocean increasing OHC is due to decadal monsoon cycles.
Googling around, I find remarkably little work has been done on this. Surprising since India will have good rainfall records going back over a century.
Without the Indian Ocean, Argo shows declining OHC in the Argo era down to 700 meters.
And Argo is the best climate data we have.
I agree with you that below 700m pre-Argo data probably isn’t worth much. Kinda like grafting tree ring data onto the thermometer record.
hotrod (Larry L), per your request, red and blue for the first two graphs:
http://bobtisdale.wordpress.com/2011/10/24/introduction-to-the-nodc-ocean-heat-content-anomaly-data-for-depths-of-0-2000-meters/
Bob:
A bit OT, but related to ocean temperature measurement.
I’ve been wrestling with a question over the last number of weeks. The question is: Why is the ocean so cold? 5,000 meters below the bottom of the ocean, the rock temperature is in the range of 800 kelvin. Temperature of the ocean at the bottom of the ocean is about 275 kelvin for a gradient of 525 k per 5000 meters or 105 kelvin per kilometer. This is about 4 times higher than the continental crust. The ocean is sucking heat out of the crust very quickly. (Still a very small flux compared to solar radiation, but a constant positive flux none the less. In addition, the surface of the planet (we are told) is, on average about 290 kelvin. So heated from above, heated from below, but colder than both. Below makes sense because cold water sinks. But sooner or later, the ocean should reach equilibrium with the atmosphere and crust. Note that for oceans, the worst of the arctic and antarctic cold is insulated by a layer of ice while the worst of the tropical heat is deeply mixed every time there is a tropical cyclone. The more I think about it, the less it makes sense. If deep mixing of the arctic / antarctic cold water is the answer, then wouldn’t this imply that the net surface temperature of the fluid cover of the earth (atmosphere plus hydrosphere) is cold. Perhaps as low as 280k? That is, is this the equilibrium temperature? I don’t want to go there because, as Dr. Curry would point out, there be dragons.
If we are to follow Dr. Pielke sr’s view, we should be looking at energy content, not flux. And looking at energy content brings us closer to the land of the dragons, because the top 14 meters of the ocean has the same mass as the entire atmosphere and I believe water is a better store of energy. As I said. It is a struggle.
If Trenberth postulates that the ‘heat is in the deep’ then sure enough, thats where it will show up.
Bingo.
Still now explanation as to how it got there …. or why there hasn’t been the requisite amount of thermal expansion.
Thanks for the color change in the charts Bob much much better!
Given that graphic display of data is such a fundamental part of the discussions that show up here on WUWT, perhaps Anthony could find someone who could present a topic on colorblind friendly data representation for the web and print.
It is a grossly under appreciated subject. Most technical documents take it for granted that their users have normal color vision (as do manufactures of technical equipment who use colored warning lights to indicate problems).
On the old Solaris hardware it was physically impossible for me to distinguish between the green LED that said all was happy and the yellow LED that said it had a problem. Even if I stood directly in front of the server and already knew it had a warning light, I still could not discern a difference between the LED colors. It is interesting that many technical careers require normal color vision, so those of us who have atypical color vision tend to get pushed into technical careers that do no have a formal color vision requirement.
As a result of that tendency to concentrate in certain fields our crew had 4 people on it, 3 Caucasian males (all of which were red green color blind) and one woman. She got to check a lot of warning lights because she was the only person on our team with normal color vision. Luckily at the time, Solaris included a command (prtdiag -v) that printed out the warning light colors so we could go to the command line and display the warning light status on servers that were alive enough to respond to command like input. For routers and switches we were stuck with what we could see. Unfortunately Solaris no longer returns that information with prtdiag -v on servers that have intel cpu’s.
This is a tangent to the topic of discussion here, so I will not comment further on this, but I would appreciate if Anthony, with the coverage that WUWT has in the technical universe made an effort to discuss this topic here, to raise awareness in the technical fields.
Larry
hotrod (Larry L) says:
October 24, 2011 at 5:03 pm
I feel your pain with the color, sounds like my color impairment is identical to yours.
Thanks Mom 🙂
Thanks for changing color codes Bob, I have a similar problem, when I am out plant collecting, I usually take an offsider who can pick red out at distance… Excellent post
They need to throw out everything before Argo or at least separate them as they are attempting to relate separate things. It appears the warming best correlates with the increase in the measurements.
ARGO only dives to 2000 meters so displaying it on a 1000-5000 meter chart is deceiving. The average depth of the ocean is 4000 meters so ARGO vertical coverage doesn’t even reach halfway to the average depth. Horizontal coverage isn’t too bad theoretically with a nominal spacing of 300 kilometers but since they drift freely they end up bunching up in stagnant areas and miss the interesting currents.
Excellent analysis once again, Bob.
I can’t understand how all that extra energy could get down to the 700-2000m level before showing up in the 0-700m level first. Surely there would either be a large blip in the 0-700m prior to the rising in the 0-2000m, or a very large drop in the 0-700 as the 0-2000 was rising.
I think you’re right in thinking that they’ve just spliced the temps of the prior years from the 0-700m, but they should have communicated that. To not do so is “alarmist”, IMV.
John Eggert says:
October 24, 2011 at 5:37 pm
“I’ve been wrestling with a question over the last number of weeks. The question is: Why is the ocean so cold?”
I’ve been trying to tell people the answer to that question for a long time. The average temperature of the global ocean is 3.9C and the only possible way for it to get that way is for the average surface temperature to be 3.9C.
A period of time of oh say 100,000 years is sufficient for even slow-ass conduction to equalize the bottom temperature with the surface temperature. This gives some perspective on the earth’s average temperature over a full glacial/interglacial cycle.
It’s fair to say that the current climate is thin skin of temporary warmth floating on a bucke of icewater. Imagine something that might disturb the mix rate between shallow surface layer (about 10% of the ocean volume has a temperature greater than 3C) such that more of that 3C frigid deep rises to the surface. Can you spell instant end to the Holocene Interglacial?
John Eggert says:
October 24, 2011 at 5:37 pm
“If we are to follow Dr. Pielke sr’s view, we should be looking at energy content, not flux. And looking at energy content brings us closer to the land of the dragons, because the top 14 meters of the ocean has the same mass as the entire atmosphere and I believe water is a better store of energy. As I said. It is a struggle.”
The ocean has over 1000 times the heat capacity of the atmosphere. Pressure reaches 1 bar, by the way, at 10 meters not 14. Don’t go diving without knowing that.
Pound for pound water has about 4 times the heat capacity of air. Given that 71% of the earth’s surface is water it works out that the first 3.2 meters of the ocean has the same heat capacity of the entire atmosphere. The average depth of the ocean is 4000 meters so it has over 1000 times the heat capacity of the atmosphere.
I’m not sure why you’re afraid of saying the answer to the question of why the ocean is so cold. The answer is scary but that’s no reason to avoid it. There’s only one possible answer and it doesn’t take a rocket scientist to figure it out.
Dave Springer says:
October 24, 2011 at 6:42 pm
I’ve been trying to tell people the answer to that question for a long time. The average temperature of the global ocean is 3.9C and the only possible way for it to get that way is for the average surface temperature to be 3.9C.
__________________________
Just curious. How much would you think that vulcanism plays into the temp of the oceans? IS there even a way to estimate something like that?
Bill Illis says:
October 24, 2011 at 5:07 pm
“That leaves the Earth 1.87 10^22 joules short or about 1.16 watts/m2 short. Space anyone? The energy is still missing.”
The answer is pretty darn simple, actually. The ocean is largely uneffected by greenhouse gases. Greenhouse gases work by slowing radiative heat loss. The ocean, unlike land, loses only 20% of the solar energy it absorbs radiatively. The great majority is lost through evaporation. CO2 doesn’t do jack diddly squat to slow down evaporative heat loss.
I think you’ll find the numbers work out rather nicely when you plug this revelation about the oceanic heat budget into the equation.
Dave Springer says:
October 24, 2011 at 6:42 pm
“The average temperature of the global ocean is 3.9C and the only possible way for it to get that way is for the average surface temperature to be 3.9C.”
Dave: That is a succint summary of my question: Is it possible for the mean ocean temperature to be lower than the mean surface temperature? If so, what is the mechanism of heat transfer that moves the energy out of the ocean while keeping the surface temperature of the ocean higher than the mean without transfering some of that energy downward into the depths. Ouch. My brain hurt just from writing that.
Jeff D says:
October 24, 20118:
“Just curious. How much would you think that vulcanism plays into the temp of the oceans? IS there even a way to estimate something like that?”
My quick and dirty guess is about 0.2 W/m² calculated as follows:
800 k temperature at bottom of crust
275 k temperature at bottom of ocean
525 k delta T
5000 m distance
1.7 W/(m.K) Thermal conductivity of basalt
0.1785 W/m² Rate of addition of heat to the ocean
(525/5000*1.7)=0.1785 = 0.2 rounded to appropriate sig figs.
If one considers 0.2 W/m² to be trivial, turn it into a total energy by multiplying by time and total ocean area. Use 1 billion years as a start for time. If you don’t like the rounding, truncate.
I could be wrong.
Cheers
JE
Jeff D says:
October 24, 2011 at 6:57 pm
“Just curious. How much would you think that vulcanism plays into the temp of the oceans? IS there even a way to estimate something like that?”
Neglible unless you’re an organism that thrives near deep thermal vents. The earth loses about 3 milliwatts/m2 of internal heat IIRC. If it were much faster than that the mantle would no longer be molten. That isn’t enough energy to make any measurable difference in ocean temperature.
John Eggert says:
October 24, 2011 at 7:17 pm
“Is it possible for the mean ocean temperature to be lower than the mean surface temperature?”
No.
Dave Springer says:
October 24, 2011 at 6:54 pm
“Pressure reaches 1 bar, by the way, at 10 meters not 14. Don’t go diving without knowing that.”
Dave: What is 10 / 0.7? Why did I divide by 0.7? Hint. I was talking about mass, not pressure.
Cheers!
JE
John Eggert says:
October 24, 2011 at 7:27 pm
“My quick and dirty guess is about 0.2 W/m² calculated as follows:”
I’m impressed. The more in depth calculation is 0.1 W/m2 and whatever source I recall saying it was a few milliwatts/m2 was off by quite a bit.
The ocean loses about 200 W/m2 at the surface so a tenth of a watt added at the bottom is stll insignificant in comparison.
Much more interesting is what happens on the surface of Venus where the interior is molten but the rocks on the surface are covered by 80 bar of CO2 which doesn’t conduct heat upward with anywhere near the efficiency of water. This changes the reduces the gradient in the crust substantially and is, contrary to urban Venusian greenhouse legend, what keeps the surface hot enough to melt lead. The greenhouse effect on Venus ends above the thick clouds that blanket the planet and make the surface as dark as the bottom of the Marianis Trench.
“Dan in California says:
October 24, 2011 at 4:25 pm
Somebody please check my numbers.”
See
http://www.engineeringtoolbox.com/specific-heat-fluids-d_151.html
The specific heat capacity of sea water at 36 F is 3.93 kJ/kgK and not 1.8 kJ/kgK. However this should not radically change your bottom line.
(I did a different calculation for a different post to answer the following question: IF we for the moment assume the air temperature were to potentially go up by 2 degrees C, but IF we then assume ALL this heat goes into the ocean instead, how much would the ocean warm up? Using mct(air) = mct(ocean), I get an answer of 0.0018 C is the increase in the temperature of the ocean.)
Gavin in a discussion with Dr Pielke claims that the heat deeper than 700 meters has acculmulated through a fast diffusive process that can not be sampled by Argo (every 11 days). This is simply nonsense. Strudies of borehole temperature logs on land have revealed the transfer of heat over the last two hundred years has been slow and has now only reached depths of 150 meters in 150 years.
http://esrc.stfx.ca/pdf/2002GL015702.pdf
Maybe somebody can explain to me what mechanism would allow heat to reach 2000 meters from the less than 1 mm skin depth of infrared penetration in less than 11 days.
Maybe somebody can explain to me what mechanism would allow heat to reach 2000 meters from the less than 1 mm skin depth of infrared penetration in less than 11 days.
Infrared penetration is irrelevant. The mechanism is that a warmer atmosphere impedes evaporation and therefore warms the oceans.
Downwelling currents could take ocean heat to the deep oceans without Argo detecting it.
Not that I think this is happening to the degree necessary.
I think Argo is giving us the correct answer. There has been no warming since 2002, excepting the Indian Ocean. Where the largest ocean to land heat transport occurs on Earth and it is known to be highly variable from the historical record.
In support of my monsoon theory, I’ll note that where the Indian Ocean OHC dips down in 2005 was when Western India had the highest monsoon rains ever recorded
Phily Bradley.
You are not paying attention. The warmists are now claiming that Argo shows that the missing heat is below 700 meters. Gavin claims that it is accumulating so fast that that Argo with an 11 day sampling period can not detect the heat flux responsible for the buildup. We all know that the documented overtuning of heat due to processess such as the gulfstream burying heat deep into the ocean at high laititudes is a relatively slow process that should be easily picked up by the ARGO’s eleven day sampling rate. I think Gavin has stuck his head out too far this time. I look for a retreat when physicist’s familar with thermodynamics cut his head off.
Thanks Bob for this excellent and thought-provoking update. The Indian and South Atlantic (SA) oceans stand out with increasing Argo-era OHC while the remaining oceans apparently cool. Looking at your ENSO SST animations, La Nina events pile up warm water in the western Pacific and this extends to south east Asia, possible influencing the Indian ocean. So is Indian Ocean warming a side effect of La Nina?
You have previously pointed to the Atlantic as the only place where there is a significant cross-equatorial current – the south-to-north South Equatorial current (north of the equator becoming the Carribean current). Is this current connected with the North Atlantic drift, such that a weakening in the North Atlantic drift might also weaken the South equatorial current? Thus the South Atlantic may be keeping its warmth rather than exporting it across the equator.
I have suggested previously that the strength of the North Atlantic drift might correlate with the AMO – evidence for this includes Barents sea temperatures (to 150m) which correlate closely with the AMO (refer to the Levitus 2009 paper cited in this post):
http://wattsupwiththat.com/2009/10/08/new-paper-barents-sea-temperature-correlated-to-the-amo-as-much-as-4%C2%B0c/
Dave Springer says:
October 24, 2011 at 6:42 pm
I’ve been trying to tell people the answer to that question for a long time. The average temperature of the global ocean is 3.9C and the only possible way for it to get that way is for the average surface temperature to be 3.9C.
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You are not alone Dave, your statement reminded me of this interesting paper.
http://greenhouse.geologist-1011.net/
The Shattered Greenhouse: How Simple Physics Demolishes the “Greenhouse Effect”.
Timothy Casey B.Sc.(Hons.): Consulting Geologist
“Notwithstanding 100 years of apparently constant mean temperature from Arrhenius to Burroughs, we may determine that the observed temperature at the altitude corresponding to the centre of absorbing mass is 4ºC or 277ºK. This, via the reasoning above, extends to an observed average absorbing mass temperature for planet earth of 4ºC or 277ºK.”
Two entirely different approaches, T. Casey calculates the above from the absorbing portion of land mass, and air column, and you from logic, considering the average ocean temperature. The resulting agreement to within 0.1°C seems pretty amazing to a school dropout like me.
‘Or is their intent to have the unsuspecting public believe it?’
Bang on the money there, a good percentage perhaps even the majority of climate science is about the politics not the science. PR and headlines grasping , helped by a ‘friendly press ‘ , seems to be a standard consideration of research in this area .
Rick C,
Gotta a link for that?
phlogiston says: “So is Indian Ocean warming a side effect of La Nina?”
Glad you caught that. Sometimes I will leave observations unwritten in a post with hope that a reader will initiate a conversation. It was what I was trying to illustrate with the OHC animations included toward the bottom of the ARGO-era OHC post a couple of months ago:
http://bobtisdale.wordpress.com/2011/03/25/argo-era-nodc-ocean-heat-content-data-0-700-meters-through-december-2010/
You wrote: “You have previously pointed to the Atlantic as the only place where there is a significant cross-equatorial current…”
I hate to contradict you, but I discuss the North and South Equatorial Currents and the Equatorial Countercurrents in the Pacific as parts of ENSO posts.
You asked, “Is this current [the Caribbean Current] connected with the North Atlantic drift, such that a weakening in the North Atlantic drift might also weaken the South equatorial current?”
The Caribbean Current is part of the North Atlantic Gyre, while the North Atlantic Drift is an offshoot of the North Atlantic Gyre. Also, I would assume a change in the North Equatorial Current and South Equatorial Currents in the Atlantic would influence one another, though I’m not sure how strong the Equatorial Countercurrent is in the Atlantic. A couple of questions for you for your research: since the equatorial currents are wind driven, do the trade winds vary independently in the North and South Hemispheres or are they both driven primarily by ENSO? Local sea level pressures (weather) would impact them, but which is the primary driver?
You wrote, “Thus the South Atlantic may be keeping its warmth rather than exporting it across the equator. “
Or the ACC may have carried warm anomalies from the South Pacific to the South Atlantic or…
philip Bradley says: “Infrared penetration is irrelevant. The mechanism is that a warmer atmosphere impedes evaporation and therefore warms the oceans.”
Please supply links to papers that document this using observational data. Your hypothesis sounds very odd to me.
Philip Bradley,
see,
http://pielkeclimatesci.wordpress.com/2011/10/21/my-recent-discussion-with-gavin-schmidt-on-real-climate/
comment of 10th October 2011 9:50pm
and
http://www.realclimate.org/index.php/archives/2011/10/global-warming-and-ocean-heat-content/comment-page-4/#comment-216643
comment 163, also 10th October 2011 9:50pm
to support Rick C’s statements.
John Eggert says: “Is it possible for the mean ocean temperature to be lower than the mean surface temperature?”
No. The oceans have their own “greenhouse effect”. They are heated by sunlight to depth but only release it at the surface, primarily through evaporation.
Bob Tisdale says:
October 25, 2011 at 2:48 am
Thanks – so I was close with the Indian ocean but off-target with the Atlantic. I guess the Atlantic ENSO complicates the picture. How’s that for a research grant application: “tracking the growth of Atlantic ENSO as the Atlantic ocean widens…”
paulhan says: “I can’t understand how all that extra energy could get down to the 700-2000m level before showing up in the 0-700m level first.”
The the most logical way, at least to me, is that the “warmer” water is being transported to depths of 700-2000 meters at high latitudes through meridional overturning circulation faster than it is being replenished at depths of 0-700 meters. The unanswerable question I now have is, is there a decadal or multidecadal component to this? The problem: There’s less than a decade of ARGO data.
Dave Springer says: “ARGO only dives to 2000 meters so displaying it on a 1000-5000 meter chart is deceiving.”
Is your statement directed to me or to NOAA? They are illustrating observations within the range of depths, not observations that cover the entire range.
“The mechanism is that a warmer atmosphere impedes evaporation and therefore warms the oceans.”
For the last 10 years at least, the thought has been that a warmer atmosphere INCREASES evaporation and humidity (that’s one of the positive feedbacks). IIRC, Dr Spencer’s work has shown that cloud cover does indeed increase at temperature rises.
Dave Springer says:
October 24, 2011 at 6:42 pm
John Eggert says:
October 24, 2011 at 5:37 pm
“I’ve been wrestling with a question over the last number of weeks. The question is: Why is the ocean so cold?”
I’ve been trying to tell people the answer to that question for a long time. The average temperature of the global ocean is 3.9C and the only possible way for it to get that way is for the average surface temperature to be 3.9C.
A period of time of oh say 100,000 years is sufficient for even slow-ass conduction to equalize the bottom temperature with the surface temperature. This gives some perspective on the earth’s average temperature over a full glacial/interglacial cycle.
I cant see how the ocean temps top to bottom will ever equilibrate, as long at there are asymmetries of heat input and output to generate currents, any more than the atmosphere could equilibrate as long as heat asymmetries generate winds. As Richard Lindzen put it a climate system at equilibrium would be “like something dead”. In such a dynamic system I doubt that it is necessary even in the long term for surface temperature to match ocean average temperature (but I dont have the maths to back this up).
Note that even 50 mllion years ago during a much warmer period, research has found evidence that there was normal ENSO cycling, implying intermittent episodes of cold upwelling in the south east Pacific of Peru, as now. Thus the warmer global climate still left cold deep water to periodically upwell.
http://wattsupwiththat.com/2011/09/19/climate-clam-chowder/
It’s fair to say that the current climate is thin skin of temporary warmth floating on a bucke of icewater. Imagine something that might disturb the mix rate between shallow surface layer (about 10% of the ocean volume has a temperature greater than 3C) such that more of that 3C frigid deep rises to the surface. Can you spell instant end to the Holocene Interglacial?
I agree entirely with this, in an ocean with strong vertical stratification with temps up to 20+ at the surface and about 3C at the bottom, ANY significant increase in vertical mixing over the whole water column, on a global scale, cannot fail to result in downward movement of heat. As Bill Illis has pointed out before, a major reason for the current glacial period in the last 20 or so million years is the isolation of Antarctica and the establishment of the strong circumpolar current, with the increase on oceanic vertical mixing this caused. The deep ocean is a cold hand from below, which can snatch away our interglacial warmth any time it chooses.
Thus changes in the extent of vertical oceanic mixing may be an important contributor to global climate swings.
“I’ve been wrestling with a question over the last number of weeks. The question is: Why is the ocean so cold?”
John, as a complete lay person I should say because the Earth, (despite the odd, brief, slightly warmer interglacial) is still in a long term ice-age.
It is many millions of years since the epoch when the world was ice-free. Hence the water at depth is still very cold.
John Eggert says:
October 24, 2011 at 7:54 pm
“Dave: What is 10 / 0.7? Why did I divide by 0.7? Hint. I was talking about mass, not pressure.”
Ah sorry. Thought you were talking about mass of the air column above the water column not mass of all the air above water or not.
The deep ocean is cool or one could say bloody cold, this missing heat of warmist fame hiding in the briny deep changing the status quo by .00poofteenth of a degree is so alarming.
This heat so near the temperature of freezing is suddenly one day going to transform itself into blistering world temperatures that set our atmosphere ablaze.
Call me stupid but I have never seen cold make things hot, this heat measured at near 4C is going to transform itself magically into atmospheric warming temperatures at some time in the near future. These people are obviously smoking some thing that is only available to government funded employees and is a national secret.
phlogiston says:
October 25, 2011 at 3:32 am
The question was: is it possible for mean ocean temperature to be 3.9C without mean surface temperature of 3.9C?
The answer is no. This doesn’t mean the ocean ever attains the same temperature from top to bottom. What it means is that a change in surface temperature will eventually be reflected in a change in bottom temperature because the top and bottom are in thermal contact. Stratification halts convection. It is physically impossible to halt conduction so while the conductivity of water is poor it isn’t non-existent and given sufficient time temperature change on the surface will be reflected by a temperature change on the bottom through conduction.
Indeed, a method of reconstructing surface temperature history over land is to bore a hole in the ground and very very precisely measure the temperature of the rocks on the way down. There are very slight changes in the temperature that depart from the constant increase in temperature due to conductivity of the rock. These slight departures reflect the change in temperature at the surface as it conducts its way down through the rock.
Bob Tisdale says:
October 25, 2011 at 3:03 am
John Eggert says: “Is it possible for the mean ocean temperature to be lower than the mean surface temperature?”
No. The oceans have their own “greenhouse effect”. They are heated by sunlight to depth but only release it at the surface, primarily through evaporation.”
That being the case then. How is it that the depths of the ocean are not warmer. The oceans move energy to space by evaporation, conduction to the air and radiation. I thouroughly understand that and can model it from first principles. But they also move heat to the depths by conduction and convection. If the surface ocean temperature has been, on average, warmer than the ocean depth, then there must be a net energy flow into the depths. Given that there is a small net heat flow into the ocean at the bottom of the ocean, the only place that surface ocean heat can go is to the atmosphere or the depths (that is, it can’t go into the crust, the crust is also a source of warming). The big picture equilibrium (yes there will be currents, etc.) temperature of the depths of the ocean should be 15C, not 4C. As with the atmosphere, warmer in some places than others, but on average 15C. As I noted, the oceans, by the insulating properties of ice should actually be warmer than the surface (in a dynamic system that freezes and thaws). The oceans are cooler than the black body equilibrium temperature of the planet. Indeed, the entire mass of surface fluid (atmosphere plus hydrosphere) is cooler than the equilibrium black body temperature. That is, there is no need for a greenhouse gas theory to explain the increased temperature of the planet because the planet isn’t warmer than an equivalalent black body radiator would be. As I said, here be dragons. For those unaware of the reference, see Dr. Curry’s sky dragons posts.
I think Argo is giving us the correct answer. There has been no warming since 2002, excepting the Indian Ocean. Additionally SL data does not support the hidden heat going into the oceans as, with out the recent continental rebound adjustments, SL is going down recently and almost flat since 2005.
Just as the land based temperature data sets are diverging ever more over the recent decade, so the SL and OHC estimates appear to be diverging ever more.
phlogiston says:
October 25, 2011 at 3:32 am
“Note that even 50 mllion years ago during a much warmer period, research has found evidence that there was normal ENSO cycling, implying intermittent episodes of cold upwelling in the south east Pacific of Peru, as now. Thus the warmer global climate still left cold deep water to periodically upwell.”
50 million years ago the earth’s mean surface temperature was only a few degrees C above today so the ocean bottom would have been 6C instead of 3C. That’s still pretty cold if it upwells into tropical surface water at 25C or more. The oceanic conveyor belt wouldn’t stop. Warm surface currents from the tropics would still travel to the pole, dump its heat, sink to the bottom, and then flow back to the tropics along the bottom.
John Eggert says: “Is it possible for the mean ocean temperature to be lower than the mean surface temperature?”
Yes, of course.
I don’t understand why someone else thinks it’s not.
The oceanic water mass is very cold, the surface water is something around 14 °C, globally averaged.
That’s a fact!
And it’s very easy to understand why the water mass is very cold while, for another reason, the surface is warm in the average. No ocean green house effect involved.
John Eggert says:
October 25, 2011 at 4:31 am
“That being the case then. How is it that the depths of the ocean are not warmer. The oceans move energy to space by evaporation, conduction to the air and radiation. I thouroughly understand that and can model it from first principles. But they also move heat to the depths by conduction and convection.”
It doesn’t move downward by convection. Tisdale is right. The greenhouse effect is primarily a result of the physics of liquid water. Shortwave energy from the penetrates to a depth of roughly 100 meters where it is eventually completely absorbed by impurities in the water. Water is quite opaque to far infrared so the solar energy absorbed below the skin layer cannot escape radiatively. That sunlight warmed water must be mechanically transported to the skin layer where it gives up the heat primarily through evaporation (70% of ocean heat loss) and secondarily (20%) radiatively. Conduction plays a role but not much of one.
So what you have is tranmission of energy into the water happening at the speed of light to a depth of 100 meters but loss of energy from the water at depth happenign at the speed of convection and conduction. Transparency to shortwave radiation and opacity to far infrared are the very properties that distinguish greenhouse gases from non-greenhouse gases. Liquid water possesses these exact same characteristics only its opacity to far infrared is complete whereas it’s only partial in greenhouse gases. We should consider liquid water and CO2 both as greenhouse fluids. Technically both are fluids and both are quite capable of producing a greenhouse effect.
Paolo M. says:
October 25, 2011 at 4:38 am
You’re talking about an instant surface temperature. We’re talking about a mean surface temperature.
Consider: the temperature of the rocks below the ocean are warmer than the ocean so the ocean cannot possibly be cooled from below. The earth is molten beneath a thin crust of solid rock. If the ocean cannot be cooled from below then it must be cooled from above. If the mean surface temperature is 16C how can that possibly cool what’s below it to 3C?
The answer is it cannot. This would violate the law of entropy also known as the second law of thermodynamics. If it were possible then perpetual motion machines would be possible.
Rick C says:
……
Maybe somebody can explain to me what mechanism would allow heat to reach 2000 meters from the less than 1 mm skin depth of infrared penetration in less than 11 days.
This is a rough outline. The paper has yet to be peer-reviewed, but will be published in full in AR5.
We will show that each water molecule in the upper layer is quantum-coupled with a water molecule in the ~2000m layer.
When an upper layer molecule absorbs photons from sunlight, its energy level is raised. This causes its quantum–coupled molecule to exist in a superposition of states, both excited and unexcited. Or neither, according to taste.
When the changed energy state of an upper molecule is detected, this collapses the probability wave and the molecule in the deep reflects this change. Recording the data from an ARGO buoy would cause this. Or perhaps Erwin’s cat or Wigner’s friend swam in the water and detected its warmth.
It follows that this instantaneous transmission of the missing heat is easily prevented; do not record any of the ARGO measurements. Or keep the cat indoors and get Wigner’s friend to stick to the pool.
Here is a discussion document that covers some of the issues being raised here as regards the role of the oceans in the global energy budget:
http://www.irishweatheronline.com/news/environment/climate-news/wilde-weather/setting-and-maintaining-of-earth%e2%80%99s-equilibrium-temperature/18931.html
I think the oceans plus solar input plus atmospheric pressure set the equilibrium temperature whilst the surface pressure distribution effects the necessary fine tuning to prevent destabilisation.
@John Eggert
“The oceans are cooler than the black body equilibrium temperature of the planet.”
Say what? The black body equilibrium temperature of the earth is usually given to be -18C with albedo assumed to be 30%.
“If the ocean cannot be cooled from below then it must be cooled from above. If the mean surface temperature is 16C how can that possibly cool what’s below it to 3C?”
As per my linked article it is atmospheric pressure that sets the net energy cost of the evaporative process. At current atmospheric pressure that value is such that the evaporation which occurs reduces the temperature of the ocean bulk (not the surface layers) to a value lower than the temperature of the rocks below and the air above.
If atmospheric pressure were higher the value of the latent heat of vapourisation would change (more energy would be needed to break the bonds between water molecules) so the temperature of the bulk ocean would rise.
If atmospheric pressure were to be lower the value of the latent heat of vapourisation would change (less energy would be required to break the bonds between water molecules) so the temperature of the bulk cean would fall further.
The net energy cost of the evaporative process changes with atmospheric pressure as witness boiling at a lower temperature at the top of Everest as compared to at sea level.
It is the net energy cost of evaporation which dictates the rate at which energy can leave the oceans and in the case of Earth’s atmospheric pressure that rate is such that given the current injection of energy from the Earth beneath and the sun above the equilibrium temperature for the ocean bulk appears to be 3.9C
GHGs cannot affect the net energy cost of evaporation (and thus the temperature of the bulk ocean) unless they affect the atmospheric pressure at the surface. They do not do so to such an extent that they alter the net energy cost of evaporation in an amount we would ever be able to measure. Instead they just alter the rate of energy flow through the system from ocean skin upwards by slightly altering the speed of the water cycle.
“Liquid water possesses these exact same characteristics only its opacity to far infrared is complete whereas it’s only partial in greenhouse gases. We should consider liquid water and CO2 both as greenhouse fluids. Technically both are fluids and both are quite capable of producing a greenhouse effect.”
Quite so:
“The Earth is known as the watery planet with 71% of the surface covered by water and in many places to a substantial depth. That water is also (in addition to the atmosphere) involved in maintaining the Earth’s temperature at a higher level than it otherwise would be.
Importantly both the atmosphere AND the oceans delay the incoming solar heat from being radiated out to space. Neither ADD new heat, both receive and store heat from the sun before it leaves the planet again. In both cases water whether in atmosphere or ocean is by far the main component in delaying the passage of heat back to space. In the atmosphere water vapour dwarfs CO2 and anything else as the main greenhouse gas. The oceans are, again, water but in a far denser form. Heat from the oceans has to be processed through the atmosphere before it can leave the planet.”
from here:
http://climaterealists.com/index.php?id=1487&linkbox=true&position=5
“The Hot Water Bottle Effect”
from July 2008
The deepest ocean temperature is just going to reflect if there is ice at the poles (whenever there is sea ice or glaciers, the deep, deep ocean is going to be around 0.0C (range of +2.0C if there is not much ice to -1.0C if there is extensive ice/ice age conditions).
As long as there is permanent ice at the poles, even the mid-level ocean is going to be about 3.0C. The immediate surface ocean might go up and down more in reaction to general surface/atmosphere temperatures but the deep ocean just reflects the weighted average temperature of the coldest, densest ocean water on the planet (the poles) over the last several thousand years.
This also means the deep ocean temperature proxies/drill cores can be used as a proxy for polar temperatures in the past. The Eocene might have been +12.0C at the poles. But polar amplification also means the global temperature average was only +6.0C. Climate scientists often taken advantage of their audience by not pointing out that global temperature change is only half that of polar temperatures. See the Eocene for an example of that as well.
@JohnEggert
I took a look at Curry’s Sky Dragon blog entry. Sure, she’s right that back radiation is real. What she misses is the difference between back radiation being absorbed by liquid water versus sold objects. Greenhouse gases operate by slowing down radiative heat loss. Land surfaces, particularly dry surfaces, lose heat primarily through radiation. The ocean however loses heat primarily through evaporation. Greenhouse gases don’t slow down the rate of evaporative heat loss therefore the insulating property they produce over land is greatly reduced over water.
“The deepest ocean temperature is just going to reflect if there is ice at the poles”
Maybe so, but weren’t we discussing the average global ocean temperature of about 3.9C and not just the deepest ocean temperature ?
The average global ocean temperature will be dependent on net energy flows in and out and in that regard the energy cost of the evaporative process is key.
If the energy cost for a given amount of evaporation changes then so will ocean equilibrium temperature and the only thing in physics that will change that energy cost is atmospheric pressure at the surface.
In theory one could alter ocean equilibrium temperature by changing the amount of evaporation but evaporation will only speed up or slow down by redistributing the surface air pressure systems. That process is a wholly negative response in the atmosphere every time the air temperature tries to diverge from sea surface temperature.
Thus changes in the rate of evaporation are always self limiting as those changes work to return surface air temperatures to match sea surface temperatures.
Thus in practice no change in the ocean bulk average temperature from changes in the rate of evaporation.
One does however see changes in the surface air pressure distribution via changes in the relative sizes and position of the permanent climate zones and that is what we perceive as climate change.
The total system energy content changes barely at all and would not do so until atmospheric pressure changes, or the sun goes to such extremes of variation that it overwhelms the water cycle thermostat.
Hence the relatively stable global temperature despite the faint sun paradox and the regular recovery of the system from asteriod strikes, supervolcanic outbreaks and the coming and going of ice ages.
What a lot of nonsense has been put here about the ocean mass temperature.
Bill Illis gave you a hint of the reason why the ocean is cold.
Not completely correct about the surface temperature.
The surface water is warm because of the SUN. As the water mass is cold because of the lack of the SUN at the Poles.
It’s the SUN….(after the continent distribution on the globe has been considered)!
@Bob Tisdale,
Thanks for the color changes, they work better for me as well.
Stephen Wilde says:
October 25, 2011 at 5:43 am
I agree with the principle that ocean water is like a greenhouse gas on steroids but I totally don’t understand how that’s analogous to a hot water bottle.
Last post (I’m sure I’ll hear a thank god or two!).
Dave Springer. How do you get -18C for the black body temperature of the earth?
Incoming flux from the sun is alleged to be 1360 w/m² (give or take a bit), SB constant is 5.67 X 10^-8, 4 times radiating surface versus absorbing surface, so T^4=1360/(4*(5.67X10^-8)), T=278 K or + 5C for a perfect blackbody radiator/absorber. Incoming solar flux would have to less than 1,000 w/m² for -18C. The -18C value includes albedo or reflectance, which would mean we are not talking about a black body.
JE
Bill Illis says:
October 25, 2011 at 5:48 am
“Climate scientists often taken advantage of their audience by not pointing out that global temperature change is only half that of polar temperatures. See the Eocene for an example of that as well.”
Patently false. The south pole has not warmed up at all. Back to the drawing board, Bill.
“I agree with the principle that ocean water is like a greenhouse gas on steroids but I totally don’t understand how that’s analogous to a hot water bottle.”
It’s as good an analogy as a greenhouse but neither analogy is perfect. A hot water bottle stores energy and releases it over time as do the oceans.
“The surface water is warm because of the SUN. As the water mass is cold because of the lack of the SUN at the Poles”
Correct so far as it goes. However if one were to change the energy value of the latent heat of evaporation by changing surface pressure then the whole mass would still change equilibrium temperature. Lower atmospheric pressure would cool the oceans and higher pressure would warm them.
No atmosphere = no oceans because they would evaporate away to space in a jiffy.
John Eggert says:
October 25, 2011 at 8:25 am
“The -18C value includes albedo or reflectance, which would mean we are not talking about a black body.”
I thought you were referring to the ocean surface as a blackbody not the center of mass of the atmosphere as the blackbody surface. Sorry about the confusion. The ocean surface of course approximates a black body very well but it receives about 30% less incident radiation than the top of the atmosphere. Its blackbody temperature is -18C when you calculate by actual amount of incident radiation it receives. Yet it is far warmer than that. It’s warmer not because of greenhouse gases but because water itself is a greenhouse fluid.
I’m sorry Mr. Tisdale, but your response to Lazyteenager is disingenuous to say the least. Both the title of this post and the caption accompanying figure 1 suggest willful deceit on the part of the NODC. And this is also the idea that numerous commenters have gotten from your post. You’re speaking out of both sides of your mouth, Mr. Tisdale. Please have the decency to either be straightforward in your accusations, or change the title of this piece and any other passage that might allude to fraud, deceit or conspiration, and correct the wrong impression that many commenters here have gotten.
Thank you.
Excellent discussion regarding the enormous potential heat sink capacity of the ocean and how small changes in cold upwelling or surface mixing can cause large surface temperature changes.
The implications of this also provides a mechanism of climate control. It is relatively easy to divert flow or induce currents (which also makes it very dangerous). The ocean’s chill is a resource that is completely untapped by Man. Very large, low energy, circulation pumps enhanced by siphon properties, are “off the shelf”, “in service”, technology and we are already dam builders.
I have no idea, however, how we get around the problem of:
– Those that control the weather/climate… control the world
– How will we ever agree (geographically) on it’s use? Certainly not the U.N., they represent nobody, no-how, no where.
Until we have useful models – we can’t start the debate! GK
Bill Illis says:
October 24, 2011 at 5:07 pm
1.0 Watt/m2 over the entire Earth over 1 year equals 1.61 10^22 joules.
I would suggest you are using the wrong approach. The one Watt over land would be a constant forcing from a black body into the gaseous shell of an open system. At the point radiative or temperature equilibrium, it would be a constant throughput and not a cumulative energy value.
You could notionally use Stefan–Boltzmanns law to calculate the rise needed in the temperature of the black body to give you the one Watt but only if you know the base temperature or radiant value of the black body. This should give you the potential temperature of the gas but the joule value would be dependent on its specific heat capacity.
Rick C says:
……
Maybe somebody can explain to me what mechanism would allow heat to reach 2000 meters from the less than 1 mm skin depth of infrared penetration in less than 11 days….
_____________________
MAGIC! or Schrodinger’s cat is in a playful mood again.
JCL says: “I’m sorry Mr. Tisdale, but your response to Lazyteenager is disingenuous to say the least. Both the title of this post and the caption accompanying figure 1 suggest willful deceit on the part of the NODC. “
The title of my post is “Introduction To The NODC Ocean Heat Content Anomaly Data For Depths Of 0-2000 Meters”:
http://bobtisdale.wordpress.com/2011/10/24/introduction-to-the-nodc-ocean-heat-content-anomaly-data-for-depths-of-0-2000-meters/
Please advise where in that title I “suggest willful deceit on the part of the NODC”?
And I will assume the caption in Figure 1 you’re complaining about is the question “Is The New 0-2000 Meter Dataset Being Introduced To Hide The Flattening Of The 0-700 Meter Data Since 2003?” How in your mind could that question imply “fraud, deceit or conspiration,” as you later write in your comment? It’s the basic question that came to mind when I plotted the 0-700 meter and 0-2000 meter datasets side by side. The one dataset flattens and the other doesn’t. And it’s the basic question that came to mind when I considered the 0-2000 meter dataset is basically source data free from 1000 to 2000 meters prior to the ARGO era.
If you’re not aware, AGW proponents are already playing with and commenting on the NODC 0-2000 meter OHC dataset. For instance, JosHag states in his 20:17 PM on 15 October, 2011 comment on the “Ocean Heat Poised To Come Back And Haunt Us?” post at SkepticalScience, “When you subtract the ocean heat uptake values of the two datasets, you should get an idea in which period the deeper ocean gains more heat than the upper ocean…
http://www.skepticalscience.com/Ocean-Heat-Poised-To-Come-Back-And-Haunt-Us-.html#65446
And of course, his graph shows a recent increase in Heat Uptake. JosHag doesn’t understand that the 0-2000 meter dataset is basically data free at depths of 1000-2000 prior to the ARGO era and that that is the reason he’s getting the results he’s getting.
Further on that thread, Jsquared in his 20:42 PM on 17 October, 2011 comment…
http://www.skepticalscience.com/Ocean-Heat-Poised-To-Come-Back-And-Haunt-Us-.html#65531
…notes, “The heating of the deep ocean after 2001 or so is indeed mostly occurring in the southern ocean, as predicted by the models used by Meehl et al.”
But Jsquared fails to understand that there is little to no data at any depth in the Southern Hemisphere south of 40S prior to the ARGO era. He’s making assumptions that are not supported by data.
Regarding your suggestion that I change the post to satisfy your concerns, I have no intent of altering the content of the post. I do not see where I’ve suggested “fraud, deceit or conspiration” on the part of the NODC.
To me, the NODC did themselves a disservice by posting this dataset before the paper. They have opened the door wide for misinterpretations by the likes of JosHag and Jsquared.
As I wrote in the opening paragraph, “We’ll just have to wait and see how the NODC intends to present this dataset.”
The concept of warm water “downwelling” to the ocean depths needs to be challenged – there seem to be some very strange ideas on this, not least the desperate idea that Trenbeth’s missing heat is winging its way to the depths. Here are my current thoughts on the subject – please take pot-shots as appropriate!
1. Major downwelling that is significant for the thermo-haline circulation (THC) ONLY involves water that is very cold – near freezing, and which has become more saline due to ice formation. This happens only at specific locations – the Norwegian sea in the Arctic, and one or more locations in the Southern Ocean between Australia and Antarctica. ONLY near freezing and super-saline water has the density to propel it to the bottom of the ocean. Warm water – or even not quite freezing water of average salinity – NEVER downwells to the bottom. Ever.
2. The deep ocean layer down to the bottom, which globally has an average depth of about 4 km but is up to 10 km deep in places, should be considered as a separate body of water to upper ocean water, and has a separate system of circulation and currents (the THC); often the surface currents and underlying THC currents are going in different and even opposite directions. They dont mix all that much, only exceptionally at locations and times of upwelling (bottom water visits the top) or downwelling (top water visits the bottom).
3. Movement downwards of warmer water does happen due to turbulent mixing, assisted by various winds, gyres and currents, down possibly to even 1-2000 m. But not to the ocean bottom. Thus downward movement of warmer water should be considered as part of mixing of the upper to mid ocean depths, but it is completely separate from downwelling in the true sense (1).
4. I agree with Bill Illis that – for as long as earth has had an ocean – the bottom water is always at about 0-3C as today, even back in the mesozoic / palaeozoic. This is partly due to the huge gravitational pressure on bottom water. Increasing bottom water temperature would require much more energy to lift the whole water column due to thermal expansion than the energy needed for the temperature change itself. So however warm it is on the surface, the bottom is always 0-3C.
5. The reason that the impossible idea of warm water somehow forcing its way down to the ocean floor displacing cold water of greater density – has caught on, is that it provides a mechanism for climate heat “memory”. For instance one observes a time lag of up to 1000 years between climate warming and CO2 increase, e.g. from the ice cores. Thus the idea of water warmed at the surface descending to the depths to emerge centuries later is appealing. It is also a potential refuge of last resort for CAGW – Trenberth’s missing heat hiding at the ocean bottom to re-emerge years later. But this does not happen.
6. However climate warming at the surface can affect long term ocean circulation in ways other than the impossible storage of warm water at the ocean floor. There is a connection – with time delay – between downwelling and upwelling, so that for instance, surface warming would reduce downwelling, which may eventually (after a delay) cause a reduction in upwelling, and the overal result is more stable stratification globally, less vertical mixing. Change to the pattern and rate of downwelling can also have complex hard-to-predict changes on the THC pattern.
7. If the rate of downwelling changes intermittently, e.g with PDO / AMO phases or solar phases, then the whole deep circulation system might behave like a nonlinear oscillator under periodic forcing. Thus cycles of alternate increased and decreased vertical mixing globally might be the response to periodic changes in downwelling in the previous hundreds or even thousands of years.
Most of this is of course pure conjecture.
No atmosphere = no oceans because they would evaporate away to space in a jiffy.
Dave Springer says:
October 25, 2011 at 8:53 am
John Eggert says:
October 25, 2011 at 8:25 am
“The -18C value includes albedo or reflectance, which would mean we are not talking about a black body.”
I thought you were referring to the ocean surface as a blackbody not the center of mass of the atmosphere as the blackbody surface. Sorry about the confusion. The ocean surface of course approximates a black body very well but it receives about 30% less incident radiation than the top of the atmosphere. Its blackbody temperature is -18C when you calculate by actual amount of incident radiation it receives. Yet it is far warmer than that. It’s warmer not because of greenhouse gases but because water itself is a greenhouse fluid.”
This is so basic, and so poorly understood. Each wavelength of incoming TSI has a different residence time within the atmosphere, land and ocean. This residence time is of course affected by it own inherent properties as well as all of the material it encounters. Only two things can effect the energy content of any system in a radiative balance. Either a change in the input, or a change in the “residence time” of some aspect of those energies within the system.” The longer the “residence time” the greater the energy sink capacity. The greater the energy capacity, the longer it takes for any change to manifest, and in the case of OHC this involves years, not annually. We simply do not know the residence time of the various SWR entering the ocean, therfore we do not know the affect of long term changes in the solar cycle. We do know that the residence time of energy entering the oceans is far longer then the residence time of energy in the atmosphere, therfore any change in the atmosphere (GHG) which reduces SWR entering the oceans may raise the atmosphere temperature, but, over time, cool the oceans.
“For instance one observes a time lag of up to 1000 years between climate warming and CO2 increase, e.g. from the ice cores. Thus the idea of water warmed at the surface descending to the depths to emerge centuries later is appealing. It is also a potential refuge of last resort for CAGW –”
Actually it is potentially fatal for CAGW because it provides a mechanism whereby energy resurfacing from the MWP could contribute to the warming of the tropopshere since the the LIA AND cause changes in CO2 absorption rates by the oceans that could result in a steady rise in atmospheric CO2 as per the Mauna Loa record. The steadiness of that rise despite variations in weather, climate and human CO2 emissions is a conundrum that needs to be addressed.
Such a process would leave little need to propose a human contribution.
It is not necessary for warm water to be advected downward to achieve a measurable effect because the thermal capacity of water is so large compared to that of air. All that would be needed would be for a solar induced warming of the system to introduce small temperature discontinuities along the horizontal route of the THC.
Thus a few hundred years of elevated solar activity could well feed slightly less cold water into the THC and slightly warmer water upwelling some 1000 years or so later.
phlogiston, regarding your October 25, 2011 at 1:23 pm comment, just a thought. Consider that the meridional overturing circulation, the subducting currents, already exist, that they’re already in motion. They have momentum. Wouldn’t it take something catastrophic to stop them?
Bob Tisdale says:
October 25, 2011 at 2:58 am
philip Bradley says: “Infrared penetration is irrelevant. The mechanism is that a warmer atmosphere impedes evaporation and therefore warms the oceans.”
Please supply links to papers that document this using observational data. Your hypothesis sounds very odd to me.
My point was that (increased) downwelling IR heating the top few mm of the oceans is not the mechanism by which the oceans warm.
The mechanism is solar radiation into the oceans, which is then released to the atmosphere primarily by evaporation. Given solar radiation is constant, the oceans warm by impeded heat loss to the atmosphere.
The main factors that effect the rate of evaporation and hence ocean heat loss are air turbulence and temperature gradient.
IR heating at the top of the ocean will have a warming effect, but the primary mechanism is that a reduced temperature gradient will reduce evaporation.
Actually measuring what happens within a few mm of the ocean surface is nigh well impossible.
RC covered this
[Link deleted by mistake. Please re-post. ~dbs, mod.]
Stephen Wilde
Rather than a change in the temperature of upwelling water, I would think it more likely that the rate, timing and maybe locations of upwelling might change.
Possibly both. Wouldn’t it be changing temperature differentials that would cause those other changes?
Bob Tisdale
Yes, thus the MOC and THC etc. really are quasi-permanent features of the earth. However rates of flow and spatial paths can change to some extent presumably.
The subducting downward arm of the MOC is the downwelling in the Norwegian sea.
Damn. Have to prove myself a liar.
phlogiston says:
October 25, 2011 at 1:23 pm
“The concept of warm water “downwelling” to the ocean depths needs to be challenged . . .”
Have you fully accounted for salinity in that comment? Saltier water, such as one gets from a hot ocean, is denser than less salty water, such as occurs where ice is melting. Which density difference is greater? Hot / cold or sweat / salty? This is a question that can be answered to a very high degree of accuracy.
Some other interesting things there. If the only source of heating in the ocean were the atmosphere, your argument (point 4) about mass of the ocean stopping heat transfer would be off on only one account. Convection (“downwelling”) is not the only method of heat transfer. Nor is downwelling the only source of convection. There is also conduction, and as you point out, there are currents of the depths and currents of the shallows. Even if these do not mix, they touch and hence heat will move from hot to cold. The warming by conduction occurs from top to bottom, so the dense thing doesn’t apply. However, the atmosphere is not the only source of heat. The crust itself is a small, almost trivial source of heat. But it isn’t entirely trivial and it is constant. You cannot continually add energy to something without raising the temperature. That heat went somewhere. If it did heat the water, there would be upwelling of heat, resulting in convective heat transfer. So again, we are faced with the question. How can something be warm on one side, warm on the other, cold in the middle, for billions of years?
MartinGAtkins says:
October 25, 2011 at 10:46 am
Bill Illis says:
October 24, 2011 at 5:07 pm
1.0 Watt/m2 over the entire Earth over 1 year equals 1.61 10^22 joules
———————————————
This is more of a definition than a calculation. 1.0 Watt = 1 Joule/second. So it is just how many seconds there are in a year times the square metres of the Earth. It is the generally accepted value.
I’m really just trying to put some context around the OHC figures which are always quoted in 10^22 joules while climate science works in Watts/m2.
The 1.61 10^22 joules just gives a reference so we can go back and forth between the two and tell how much the OHC is supposed to be rising.
Here is another frame of reference:
– 1.61 10^22 joules = 40,497,031,894,556,800,000,000,000,000,000,000,000,000
individual photons of sunlight or 0.4% of the total energy received by the Earth from the Sun in a year.
philip Bradley says:
October 25, 2011 at 3:54 pm
“Given solar radiation is constant, the oceans warm by impeded heat loss to the atmosphere.”
Solar radiation is not constant, it varies considerably, and even more at the surface. Even the GHG, CO2 affects TSI at the surface.
Thanks to Bob Tisdale for another well done, thought provoking analysis of oceanic temperatures. It launched lots of interesting commentary. Some of comments most interesting to me were offered by JeffD (“How much would you think vulcanism plays into the temp of oceans?”) and responses by
John Eggert (“… about 0.2 W/m^2) and
Dave Springer (“… the more indepth calculation is 0.1 W/m^2. The ocean loses about 200 W/m^2 at the surface so a tenth of a watt added at the bottom is still insignificant in comparison.”)
Should not the question of ‘significance’ regarding vulcanism as a subsea heat source be evaluated relative to the alleged/postulated TOA heat transferred to deep water rather than relative to ocean surface heat transfers? I think so. And, assuming JeffD is/was the term “vulcanism” to mean volcanic eruptions I believe the discussion merits expansion to include all forms of geothermal heat releases, including subsea hydrothermal venting, non-eruptive magma and lava emissions, and explosive volcanic blasts.
A source cite is not handy but I seem to recall reading about a 44 TW (10^12 Watts) estimate of Earth’s “heat engine” production from radiogenic (radioactive decay) processes. http://www.sciencemag.org/content/321/5897/1825.abstract suggests “Sub-seafloor hydrothermal convection at mid-ocean ridges transfers 25% of the Earth’s heat flux ….” I read that estimate as applying to ocean ridge hydrothermal convection transfers only (exclusive of vulcanism) and implying hydrothermal transfer of ~11 TW of heat into the oceans. Disregarding “vulcanism”, those estimates imply crustal conductive heat transfer of 33 TW. With oceans covering ~ 70% of earth’s surface, 23.1 TW of that residual 33 TW would transfer into ocean waters. Geothermal heat transfers of 11 TW + 23.1 TW = 34.1 TW in ocean waters is implied or about 77% of the heat generated by earth’s radiogenic “heat engine.” Including consideration of magma and lava emissions (1200°C) would almost surely increase the share of earth’s total geothermal heat flowing into oceans. http://volcano.oregonstate.edu/eruption-rates suggests 3/4 of all magma and lava production occurs along/around mid-oceanic ridges.
With average mid-ocean ridge-crest water depth of ~2,500 meters, it appears plausible that more than 17 TW of geothermal energy flows from the mantle/crust into ocean waters at depths greater than 700 meters on a relatively steady basis. But, there is little reason to presume it is constant or “steady state” heat production or transfer according to http://www.columbia.edu/itc/ldeo/v1011x-1/jcm/Topic3/Topic3.html.
I haven’t done the math to generate an estimate comparable to those provided by John Eggert and Dave Springer but in light of the above believe their estimates could be on the low side due to reliance on too little energy input as well as due to likely focus on too much water (total ocean water volume vs waters deeper than 700 meters).
Solar radiation is not constant, it varies considerably, and even more at the surface. Even the GHG, CO2 affects TSI at the surface.
TSI = Total Solar Irradiance or Total Solar Insolation
I accept that there is not enough variation in TS Irradiance to explain the apparent climate warming.
TS Insolation is a whole other matter and involves multiple factors, including the elephant in the climate room – clouds.
Anyway my intent in using ‘given’ was to avoid a debate about changes in Total Solar Insolation.
The deleted RC is link is
http://www.realclimate.org/index.php/archives/2006/09/why-greenhouse-gases-heat-the-ocean/
RC is generally good on the basic science. They get unreliable when discussing evidence for AGW.
phlogiston says:
“Rather than a change in the temperature of upwelling water, I would think it more likely that the rate, timing and maybe locations of upwelling might change.”
Possibly both. Wouldn’t it be changing temperature differentials that would cause those other changes?
“How can something be warm on one side, warm on the other, cold in the middle, for billions of years?”
Because the net energy cost of evaporation (linked to surface pressure) is so high that after taking evaporation into account the rate of energy loss by the oceans is so large that the equilibrium temperature at the current level of geothermal input from below and solar input from above falls to 3.9C which is apparently the average global ocean temperature.
“IR heating at the top of the ocean will have a warming effect, but the primary mechanism is that a reduced temperature gradient will reduce evaporation.”
Actually the AGW contention (from only one scientists as far as I can tell) is that the warmed molecules at the top of the ocean skin change the temperature gradient from below and therefore inhibit upward energy flow from ocean bulk to ocean skin and thence to air which in theory alters the equilibrium temperature of the oceans via the operation of Fourier’s Law.
I have discussed that very point extensively elsewhere and come to the conclusion that that is not so because the increase in evaporation (a net cooling process) offsets the change in gradient that would otherwise occur.
Furthermore once the increased evaporation rate has used up the downward IR there is no energy left over to add to ocean heat content.
The net effect of downward IR on the background energy flow from ocean to air is therefore zero and GHGs cannot warm the ocean bulk.
Instead the extra energy remains in the air and gets converted to latent form and is then whisked away upward by convection for faster discharge to space.
All one sees is a miniscule change in the speed of the water cycle which pales into insignificance compared to solar and ocean induced changes in the water cycle.
Dave says:
October 25, 2011 at 5:47 pm
Thanks Dave, you are correct I was thinking about all the undersea activity. I know its not a constant but the amount of heat being sinked from all the lava flows, vents has to make some kind of impact. What was crossing my mind is that during increased levels of vulcanism that the up flow of heat generated would bring some of the cold deep water with it and provide some level of mixing. If it does it would seem to be on a small scale.
Being a diver I have personally experienced thermocline and have read the definitions of the effect but it still seems strange to me that the heat from the upper level traps and cannot to any large degree heat the lower layer. If I understand it right the increased density of the colder water makes it sink and the lighter warmer riders on top of it. So gravity is the mediating factor in the effect but still strange that heat will not easily cross this boundary. I know there is a tidal/gravity anomaly that is persistent to the NW of Australia does the thermocline behave the same there? This anomaly can also be seen in the sea level global height map.
John Eggert says:
October 25, 2011 at 4:24 pm
Damn. Have to prove myself a liar.
phlogiston says:
October 25, 2011 at 1:23 pm
“The concept of warm water “downwelling” to the ocean depths needs to be challenged . . .”
Have you fully accounted for salinity in that comment? Saltier water, such as one gets from a hot ocean, is denser than less salty water, such as occurs where ice is melting. Which density difference is greater? Hot / cold or sweat / salty? This is a question that can be answered to a very high degree of accuracy.
The Red Sea is one place where hot super-saline water does exist in packets at the sea bottom – hotter than the water above. So enough salinity can overcome temperature to determine water’s density. But this is the exception that proves the rule.
However, the atmosphere is not the only source of heat. The crust itself is a small, almost trivial source of heat. But it isn’t entirely trivial and it is constant. You cannot continually add energy to something without raising the temperature. That heat went somewhere. If it did heat the water, there would be upwelling of heat, resulting in convective heat transfer. So again, we are faced with the question. How can something be warm on one side, warm on the other, cold in the middle, for billions of years?
Yes there is geothermal input to the oceans. So indeed how can it be that, both in the tropics with surface water temperatures of 30+ C, and at the poles with surface water freezing, abyssal water is always 0-3C? How can near freezing water be sandwitched between warm surface and warmer bottom? The answer is when you have a 4000 m thick layer of a liquid with the extraordinary heat capacity of water, on a planet with gravity of 10 n.kg-1. (Most of the sea floor is cold despite volcanic activity in some places.)
Regarding the contribution of geothermal heating to the ocean heat balance I would recommend this paper as a starting point.
http://www.ocean-sci.net/5/203/2009/os-5-203-2009.pdf
Geothermal heating, diapycnal mixing and the abyssal circulation
J. Emile-Geay 1 and G. Madec 2,*
From the abstract
Geothermal heating and diapycnal mixing are found to interact non-linearly through the
density field, with geothermal heating eroding the deep stratification supporting a downward diffusive flux, while diapycnal mixing acts to map near-surface temperature gradients onto the bottom, thereby altering the density structure that supports a geothermal circulation. For strong vertical mixing rates, geothermal heating enhances the AABW cell by about 15% (2.5 Sv) and heats up the last 2000 m by ∼0.15◦C,reaching a maximum of by 0.3 ◦ C in the deep North Pacific.
Prescribing a realistic spatial distribution of the heat flux acts to enhance this temperature rise at mid-depth and reduce it at great depth, producing a more modest increase in overturning than in the uniform case. In all cases, however, poleward heat transport increases by ∼10% in the Southern Ocean. The three approaches converge to the conclusion that geothermal heating is an important actor of abyssal dynamics, and should no longer be neglected in oceanographic studies.
From the discussion section
The case is hereby made that geothermal heating is an important actor of abyssal dynamics. We recommend its inclusion in every model dealing with the long-term ocean circulation, for it substantially alters bottom water mass characteristics and generates a non-negligible circulation in the present-day climate. Further, recent results by Dutay et al. (2008) confirm its importance in correctly simulating tracer distributions in the deep ocean.
philip Bradley: Your reply excluded the requested papers. An RC link to, assumedly, a field study does not suffice.
wyn palmer
re:
http://pielkeclimatesci.wordpress.com/2011/10/21/my-recent-discussion-with-gavin-schmidt-on-real-climate/
The tenacity with which Gavin clings to the unscientific methodology used to determine the ‘global average temperature’ is quite remarkable.
I suspect that Gavin knows that the methodology is seriously flawed and further he knows that to concede the flaws and move to a more scientific basis will bring the AGW house of cards down.
philip Bradley: Your reply excluded the requested papers. An RC link to, assumedly, a field study does not suffice.
I thought a field study was what you wanted.
Otherwise, The global average SST is 2C to 3C higher than global average surface air temperature. Warm the atmosphere = reduce the temperature gradient and heat transfer is reduced.
This simple fact tends to get lost.
Correction to my above post. NE of Australia.
Philip Bradley says: “Otherwise, The global average SST is 2C to 3C higher than global average surface air temperature.”
Which Marine Air Temperature dataset are you using for your combined Land Plus Marine Air Temperature Data, COADS or MOHMAT? What land surface temperature dataset are you using for your LST data, since the big three land surface temperature datasets are provided in anomalies? Please graph them to show the 2 to 3 deg C difference and identify what datasets you’ve used.
You continued, “Warm the atmosphere = reduce the temperature gradient and heat transfer is reduced.”
Your original statement was that evaporation was reduced. Are you changing your hypothesis?
Also, please plot the Sea Surface and Marine Air Temperature datasets upon which you are basing this assumption and illustrate which temperature dataset, Sea Surface or Marine Air, rises faster–and explain why, based on your assumptions.
The reason I ask, as you may be aware, I’ve dissected the satellite-era Sea Surface Temperature data (the Reynolds OI.v2 SST dataset), and I cannot find any evidence of anthropogenic greenhouse gas warming in that dataset. Volcano-adjusted SST anomalies for 33% of the planet (the East Pacific Ocean [90S-90N, 180-80W] have not risen during that time. And all of the rise since 1982 (the start of that dataset) for the rest of the world can be explained as multiyear responses to ENSO, combined with the additional variability in the North Atlantic caused by the Atlantic Multidecadal Oscillation. It’s actually very easy to see, once you know how ENSO works. Refer to the posts:
http://bobtisdale.wordpress.com/2011/07/26/enso-indices-do-not-represent-the-process-of-enso-or-its-impact-on-global-temperature/
And:
http://bobtisdale.wordpress.com/2011/08/07/supplement-to-enso-indices-do-not-represent-the-process-of-enso-or-its-impact-on-global-temperature/
If the sea surface warming is not a result of AGG, one might conclude the warming of the oceans to depths of 700 meters also cannot be caused by AGG. I was grateful when KNMI added the NODC OHC data (0-700 meters) to its Climate Explorer website a few years ago. It allowed me to illustrate and discuss how the rise in OHC can be due to natural variables as well: ENSO, changes in Sea Level Pressure, and AMO/AMOC. Refer to:
http://bobtisdale.blogspot.com/2009/09/enso-dominates-nodc-ocean-heat-content.html
And:
http://bobtisdale.blogspot.com/2009/12/north-pacific-ocean-heat-content-shift.html
And:
http://bobtisdale.blogspot.com/2009/10/north-atlantic-ocean-heat-content-0-700.html
I had to think about the heating issue of water in a context that my simple mind could understand. Water is not near as good of a heat conductor as I was thinking. A home hot water heater is the simplest analogy that came to my mind. The temperature gradient falls off very fast as the pipe leaves tank.
Is there any known method that would allow a double inversion layer as in heat/cold/heat ? With the heated water being less dense it seems to me that it will always find a way to rise. Are there any studies that shows how the heat generated from the sea floor vents dissipate?
Bob,
If from 1,000 to 2,000 meter dataset is basically “data free” would it not be appropriate to note on your primary chart that prior to year 2000 the OHC 0-2000m curve is simulated. Possibly instead of a solid red curve prior to 2000, using a dashed curve? I think that would make it clearer to the average person that prior to year 2000 the data is questionable (i.e. flaky/flimsy).
Like many others before, great post.
Some amazingly silly nonsense in some of these posts. Tropical lake bottom temperatures give us some idea of what the minimum seasonal temperatures are. In the temperate zones they hang around the T of maximum density, a few degrees above freezing. They sure don’t tell us anything about average surface T.
Paolo and Illis are right. Springer and phlogiston are full of it. And Paleozoic ocean bottoms? Certainly much warmer than now–what does pressure have to do with anything? This thread has devolved into another disgrace to basic physics.
Even swimming pools instruct us–they tend to be colder than the average air temperature even when they’re covered. They tend toward the nightime temperature simply because cold water descends, and warm water–all water–insulates. Some of the skeptics around here give the rest of us a bad name.
–AGF
“Even swimming pools instruct us–they tend to be colder than the average air temperature even when they’re covered. They tend toward the nightime temperature simply because cold water descends”
That doesn’t sound right.
When a strong sun shines into a pool the water near the surface gets warmer than the air above.
At night the air cools faster than the water so the water becomes warmer than the air.
I think AGF is confused because water in a pool FEELS cold even on a sunny day but that is only a matter of percepton because the water in the pool is lower than body temperature and due to the high thermal capacity of water it pulls energy out of the skin faster than does air at an even lower temperature.
That is why one gets hypothermia faster in water than in air of the same (or even lower) temperature.
To put it more clearly: water can only be heated from the bottom up; it can only be cooled from the top down. Polar winters are many orders of magnitude more effective at cooling than earth heat is at warming.
Here is a thermocline by month for the Sea of Galilee (Lake Kinneret): http://www.ilec.or.jp/database/asi/asi-09.html
Notice that at 40 meters T strays little from the minimum surface T. –AGF
Steve, let us count the ways we warm ourselves when drying off with a towel:
1. The towel insulates, like a blanket.
2. The towel removes water, reducing evaporative cooling.
3. The exertion excercises our muscles, warming us.
4. The towel may block the wind, reducing both evaporation and wind chill.
5. The act of drying constitutes friction, warming the skin.
Have I left anything out?
“To put it more clearly: water can only be heated from the bottom up; it can only be cooled from the top down”
Don’t oceans warm at the top when the sun shines on them and cool from the top when the sun is not shining ?
The Sea of Galilee would not have a significant Thermohaline Circulation and so landlocked bodies of water are not a good comparator.
Sure, different frequencies penetrate different depths, and light penetrates deepest, but this radiation can’t heat water any deeper than it can penetrate, whereas conductive cooling can affect the entire ocean, just as bottom heating can. Of course fresh water lakes present a very simple case, but this basic model is obiously lost on some of the commenters. The point I’m trying to make is that average surface T has nothing to do with ocean T in general, as the Sea of Galilee shows nicely. Obviously the deep ocean is warmer than the minimum surface T at the poles, so other factors are at play, including bottom heating and layer mixing.
Bob has some great points, but some people take it a bit too far.
http://itsnotnova.wordpress.com/2011/12/03/the-nova-travesty-cherry-picker-ahoy/