Guest Post by Willis Eschenbach
I previously discussed the question of error bars in oceanic heat content measurements in “Decimals of Precision“. There’s a new study of changes in oceanic heat content, by Levitus et al., called “World Ocean Heat Content And Thermosteric Sea Level Change (0-2000), 1955-2010” (paywalled here). [UPDATE: Available here, h/t Leif Svalgaard] It’s highlighted over at Roger Pielke Senior’s excellent blog , where he shows this graph of the results:
Figure 1. From Levitus 2012. Upper graphs show changes in ocean heat content, in units of 1022 joules. Lower graphs show data coverage.
Now, there’s some oddities in this graph. For one, the data starts at year 1957.5, presumably because each year’s value is actually a centered five-year average … which makes me nervous already, very nervous. Why not show the actual annual data? What are the averages hiding?
But what was of most interest to me are the error bars. To get the heat content figures, they are actually measuring the ocean temperature. Then they are converting that change in temperature into a change in heat content. So to understand the underlying measurements, I’ve converted the graph of the 0-2000 metre ocean heat content shown in Figure 1 back into units of temperature. Figure 2 shows that result.
Figure 2. Graph of ocean heat anomaly 0.-2000 metres from Figure 1, with the units converted to degrees Celsius. Note that the total change over the entire period is 0.09°C, which agrees with the total change reported in their paper.
Here’s the problem I have with this graph. It claims that we know the temperature of the top two kilometres (1.2 miles) of the ocean in 1955-60 with an error of plus or minus one and a half hundredths of a degree C …
It also claims that we currently know the temperature of the top 2 kilometers of the global ocean, which is some 673,423,330,000,000,000 tonnes (673 quadrillion tonnes) of water, with an error of plus or minus two thousandths of a degree C …
I’m sorry, but I’m not buying that. I don’t know how they are calculating their error bars, but that is just not possible. Ask any industrial process engineer. If you want to measure something as small as an Olympic-size swimming pool full of water to the nearest two thousandths of a degree C, you need a fistful of thermometers, one or two would be wildly inadequate for the job. And the top two kilometres of the global ocean is unimaginably huge, with as much volume as 260,700,000,000,000 Olympic-size swimming pools …
So I don’t know where they got their error numbers … but I’m going on record to say that they have greatly underestimated the errors in their calculations.
w.
PS—One final oddity. If the ocean heating is driven by increasing CO2 and increasing surface temperatures as the authors claim, why didn’t the oceans warm in the slightest from about 1978 to 1990, while CO2 was rising and the surface temperature was increasing?
PPS—Bonus question. Suppose we have an Olympic-sized swimming pool, and one perfectly accurate thermometer mounted in one location in the pool. Suppose we take one measurement per day. How long will we have to take daily measurements before we know the temperature of the entire pool full of water to the nearest two thousandths of a degree C?
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How long will we have to take daily measurements before we know the temperature of the entire pool full of water to the nearest two thousandths of a degree C?
Until it has all evaporated, then the temperature of the liquid water in the entire pool will be Null with 100% accuracy, no data, no error.
But but its peer reviewed and paid for. Of course it would be nice to know payment and support details along with the error bars to Thousands of dollars.
paper here: http://www.leif.org/EOS/2012GL051106-pip.pdf
the answer to PPS is NEVER. unless of course you have some how devised an adiabatic pool environment.
James Annan found some gross maths errors in Levitus et al 2000. Once he pointed out the maths error, Levitus et al’s corresponding author stopped corresponding with him…
I don’t trust any OHC figures prior to ARGO and I don’t trust the manipulation of ARGO data after 2007 either.
I am 52.31847295482937529573648254482% confident in the results. GK
put another way- it looks to me that the gross energy content of the ocean is on the order of 10^27 J? so we are looking at changes somewhere around 0.01% to 0.001%? please
PPS answer(s)
Outdoor pool: Never, each new day brings different ambient conditions.
Indoor pool in a tightly climate controlled environment: 500,000 days
So the oceans have warmed about 0.1C over the past 57 years but the Earth has warmed by 0.8C since 1979. Whats wrong with that picture, especially since the oceans cover 70% of the Earth’s surface and constitute 98+% of the heat sinking capacity. I don’t believe it.
PPPS: How much CO2 will be outgassed from the oceans based on the presumed 0.1C temperature increase of the oceans?
Bill
This at least is possible and no contradiction. Ocean currents and therby connected heat transfer and overturn occurs on all timescales in the ocean. These variations may conceivably be due to heat moving in or out into/from deeper ocean layers.
Howver and regarding the ‘accurate measuring’ problem, a more viable method to determine (estimate) changes in in total ocean heat content would be through measuring sea level changes accurately. And this can be done at the surface, and with less probes (‘thermometers’) than in the swimming pool /the oceans, since gravity does not change over the time scales considered here.
Thermal heat expansion of ocean water is ~independent of water temperature, and thus changes in heat content and total volume match each other well. The contamination there is from melting land ice, and possibly a little from changing water content of cultivated land areas. Both these, however, should be easier to estimate/measure than 2000m ocean heat content using thermometers.
Inhuman claims of accuracy is a requirement of the job.
Climategate Email 0700.txt
K Hutter added that politicians accused scientists of a high signal to noise ratio; scientists must make sure that they come up with stronger signals. The time-frame for science and politics is very different; politicians need instant information, but scientific results take a long time
And stop insulting the work of other scientists Willis – Climategate Email 4693.txt teaches us:-
Maybe it is an illusion or prejudice on my part,
but somehow I am not convinced that the “truth” is always worth
reaching if it is at the cost of damaged personal relationships….
Deep sea thermal vents were not even discovered until 1977. Just sayin’.
And how many measuring devices were extant during this period that measured columns from 0 to 2000 meters and at what sampling frequency? Today our wide cast devices only meaure to 700 meters. So when and where did the other 1300 meters of measurement come from and at what percent coverage? To put it mildly, BULL HOCKEY! [ or.. water hockey (stick)]
Are they actually trying to claim that after about 1994, they have 100% of the ocean measured?
Whether they are right or wrong I don’t think that they are claiming that. They are claiming to measure the average heat content over a five year period. (It is because they are taking the average that it makes more sense to think in terms of heat content that temperature.) Maybe their error bars are too small. But the error bars on an average will be smaller than the error bars on an individual measurement. An intuition that starts by thinking about a point measurement in a larger body or over a short period of time is unlikely to be correct. What is needed is analysis, not simple incredulity.
Willis: A free draft of the Levitus et al (2012) paper is available through the NODC website:
http://data.nodc.noaa.gov/woa/PUBLICATIONS/grlheat12.pdf
Regards
Climate science needs something like the ISO 9000 quality control standards used by industry.
REPLY: Yep, I argued for this back in 2008:
http://wattsupwiththat.com/2008/09/23/iso-8000-data-quality-something-climate-science-could-benefit-from/
-Anthony
The numbers would appear to indicate the error lies in their estimate of ocean coverage
How did they achieve 100% data coverage at 700 meters starting in 1994? How did coverage at 2000 meters peak in 1994?
What exactly is their definition 100% coverage? Is it one reading per cubic meter per second, or one reading per cubic mile per year? Or is 100% coverage one reading per 1000 cubic miles per decade?
What is the volume of water measured and the number of readings over time, and how random is the sample?
If the measurements are taken from ships they are not at all random because shipping lanes are not random, they are determined by geography and weather patterns. There are large areas of the oceans where commercial shipping never travels, and other areas where shipping is highly concentrated.
Question #2
Answer
You will never know the temperature of the pool to within two thousandths of a degree C. All you will know is the temperature at that particular spot, to within the accuracy of your thermometer. The pools that I have been in have warm and cold spots.
When Warmistas promulgate their cargo-cult ‘science’,
you’re supposed to genuflect and vote to outlaw carbon dioxide.
Error-finding critiques are only for ‘deniers’, not for Warmista Scripture.
When a Warmista claims accuracy of 1 part per trillion, then accept it!
Have faith in science and shut up! Don’t scrutinize, don’t doubt, don’t even look!
G. Karst says:
April 23, 2012 at 7:30 am
I am 52.31847295482937529573648254482% confident in the results. GK
============================================
And it’s a well-established fact that 76.38% of all statistics are made up on the spot
Thank you for your analysis – I’m going to show this to my teenage daughters as an example of how what some scientists present as “settled science” can be demolished in several paragraphs by other scientists; ie in minefields we cannot afford to passively “be informed” but must consider different views.
Willis, I agree completely; having spent 15 years with a Fortune 50 Aerospace company as the senior process/quality engineer for the division, and also as a past Chairman of the American Society for Quality. You’ve just encapsulated everything I see wrong about the entire AGW meme. Thank you. 🙂
Leif provides a link to the paper (Thanks!), that includes this scarey bit”
“If this heat were instantly transferred to the lower 10 km of the global atmosphere it would result in a volume mean warming of this atmospheric layer by approximately 36°C (65° F).”
Then they admit this can’t and won’t happen. I wonder whose idea it was to make this calculation and why? Why not calculate how many vaporized climate scientists can dance on the head of a pin? Equally useful.
You don’t have to be a climate expert to see how badly the paper has been reviewed.
The legend for the y-coordinate in Figure 1 should read “Heat content ANOMALY”
From a process engineering standpoint, it is impossible to get such high precision.
I work at a bakery, where we make about a million lbs of bread each week (seasonally averaged). We have a machine called a proof box. It is a room with about the same internal volume as an olympic sized swimming pool. The bread moves through this room on a continuous conveyor line. We have both wet and dry bulb thermometers placed throughout the interior, and we run a device called a mole through periodically to callibrate our climate controls. The climate controls inside our proof box are state of the art. There is a direct connection between our ability to control that environment precicely and our quality/profitability. Bread that doesn’t rise properly ends up going in the pig feed trailer. When money is at stake, you can bet your left leg that every effort is made to get it right. I can tell you that in a fluid such as air or water, convection can lead to very uneven temperature profiles. The temperature you read at any given location may be totally unrepresentitive of the temperature just a few feet away, and no given set of temperature/humidity readings can ever be assumed to be representative of the area as a whole. We have seen faulty trends of increase and/or decrease many times due to the quirky ways air can circulate inside the box and/or problems with the instruments.
As an added note: Taking two readings seperated by some space and assuming that the area between them has a value averaged between the two measurements is insane.