This is a reply and extension to Pat Frank’s “Earth Abides” post (sorry, couldn’t resist) which appeared here recently. The post features an intriguing interpretation of the temperature record to deduce climate sensitivity to CO2. I thought I would try to recreate it and see where it took me. First I got the HadSST records from http://www.cru.uea.ac.uk/cru/data/temperature/.
I generally prefer to use sea-surface temperatures when looking at global trends for several reasons:
- they have a lower variance, indicating a better stability to short-term perturbations
- the surface water temperature is measured directly, eliminating some of the definitional issues of surface air temperature
- SST’s are free of siting issues, UHI, land use, and other local human climate effects
- The seas are 70% of Earth’s surface and its major heat reservoir. Temperatures can go up and down on land like a wagging tail, but the oceans are the dog.
So let’s take the SST record and fit a sinusoid to it. However, a linear fit to the secular rise simply can’t be right. It would retrodict an ice age right at the peak of the Roman Empire. Since things in nature are much more often cyclical, I tried fitting another sinusoid to the secular rise, using all the HadSST data back to 1850:
Here we have the data as dots, decadal smoothing in blue, and the fitted sum of cosines in red. (Decadal smoothing means that I convolved the data with a Gaussian with a 5-year standard deviation.) The red curve is simply the sum of two cosines, one of period 62.7 years, the other 259.9. Just how good a match is it for the data? Ignoring intra-decadal variability (weather, not climate!), let’s plot the decadally-smoothed residual:
Something very unusual happened around 1950 — that’s nearly an 8-sigma excursion. And I haven’t the slightest clue what it was. (There was a major mode shift in the PDO about that time; it was also the era of atmospheric nuclear weapon testing … and there was probably a drop in the number of pirates.) If you look at the actual data you’ll see that 1945 marks the only really drastic discontinuity in the entire record — so I feel reasonably comfortable saying that something unusual happened then. Given that the fit was so good outside the “1950 notch”, I did the fit treating the notch as an outlier (yellow line) for an even better fit (especially to recent temperatures). (That means, of course, that the model isn’t just the fit but the fit with an exception for the notch.) The red lines are one standard deviation, the magenta two. But outside of the notch, this model — a tiny one, 6 parameters — fits the decadal average SST to within 0.05 degrees for 160 years.
Here are the variances, again with the notch taken out (We take the notch out because it makes all the series correlated, so the variances wouldn’t sum. Since we explicitly say the model can’t explain the notch, we’ll concentrate on where it does match the data.):
| Raw SST data | 0.0687 |
| Model fit curves | 0.0534 |
| Residual to fit | 0.0153 |
| Data – smoothed (decadal variability) | 0.0145 |
| Smoothed – fit (model error) | 0.000513 |
In other words, decadal variability (weather!) accounts for 21% of the variance of the raw temperature series, the model accounts for 78%, leaving about 1% unaccounted for. (There’s still a tiny amount of correlation.)
But this kind of messes up the notion that there was a V-shaped piecewise linear structure to the residual across the twentieth century: the data much more clearly show a straight line with a dip than falling and rising linear trends. Yet Frank’s graph looked a lot more like the trends — what happened?
The key to the puzzle is that his data were (or included?) land temperatures, the CRUtemp data. Let’s plot that too, also as a residual to our fit curve:
Lo and behold, there really is a linear rise above the sinusoid in the land data — which isn’t there in the SST data. In other words, the divergence since 1950 is more a land-water difference than a CO2-no CO2 one. Sorry to rain on the parade, but I can’t really buy the climate sensitivity deduction. As mentioned, there are several possible explanations for the difference. We can add another one, even assuming the land temperature measurements are perfectly accurate: cloud feedbacks may operate differently over land and ocean.
I think you have the 2nd and 3rd graphs switched.
REPLY: Edit error in loading graphs – fixed and thanks for pointing it out – Anthony
There was non-stop war with all requisite air and surface bombardments from 1939 to the early 1950’s followed by the atmospheric “nukular” testing. Is what you are seeing perhaps the lagged effect of the non-stop conflagration?
The only way I can make sense out of this is to assume that the last two graphs were transposed.
REPLY: Edit error in loading graphs – fixed and thanks for pointing it out – Anthony
On the 1945 discontinuity:
http://climateaudit.org/2007/03/18/the-team-and-pearl-harbor/
http://www.realclimate.org/index.php/archives/2008/06/of-buckets-and-blogs/
If you run the 5 year gaussian smoother by itself without the applying the model first, it will absorb both the 259.9y and 62.7y low frequency signals represented by the model, and you’ll probably get the rsultant smoother to explain 78+21=99% of the variability.
Further, if you intend on using the model to apply beyond the range of the data, you’d need something more to justify extrapolating from the 160y data range of the to the rest of the 259.9y period of half of your model.
Discrete Cosine Transformation is a great data compression technique, but I’m not sure much inference about causality can built from the first few wavelets or their residuals.
I am a bit puzzled about your last graph. I am assuming it is temperature anomaly on the x. Is that Fahrenheit or Celsius? Would help if you could include dimensions/ If it is Celsius, it does not make sense to my own measurements of 0.018 degrees C warming per annum since 1974 / measured by linear regression, see
http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming
Something very unusual happened around 1950 — that’s nearly an 8-sigma excursion. And I haven’t the slightest clue what it was. (There was a major mode shift in the PDO about that time; it was also the era of atmospheric nuclear weapon testing … and there was probably a drop in the number of pirates.) If you look at the actual data you’ll see that 1945 marks the only really drastic discontinuity in the entire record — so I feel reasonably comfortable saying that something unusual happened then.
J Storrs Hall
Nothing unusual happened arround 1950, if you look at proper data records for real temperatures, rather than the dubious (& irrational) global SST.
If there was anything unusual in the 20th century is the winter warming 1900-1930, while other seasons are left lagging behind , while the other seasons are left lagging behind, then the sudden drop 1930 – late1940 while the rest continued on the upward slope.
Sorry forgot the link to the graph
http://www.vukcevic.talktalk.net/CET-NAP.htm
I believe we have a big problem with understanding the mechanisms of temperature rises and falls on Earth because we take too large a time-frame and location view. For example, if you look to find the big temp rises that lead to Hansen’s fears, you have to look outside the contiguous US, as the temps haven’t risen since 1996. The same is elsewhere – sometimes the area is cooler now than before. To cut to the chase, for the global temperature rise of concern, you have to include the Arctic. The Arctic is the only place with large numbers.
I looked at the SST on a longitude basis and a year-to-year basis. If you line the records up you get a y-axis of location and an x-axis of time. The variations in the record are temperature. In geology and geophysics we do this, though the y-axis is depth and the x-axis is location. The variations are lithology or fluid content changes. What you get geologically is how formations rise, fall and change over a depositional area. What you get with the same display style for the SST is how heat moves through the system along longitude through time.
The analysis is not easy, no more easy than it is for a geologist or geophysicist to interpret the changes in his “graphs” (we call them cross-sections or seimsic lines). But gross changes are visible to anyone who doesn’t need a white cane.
You could do the same with latitude changes vs time, obviously. The work would come down to finding which area shows the greatest concordance, determining the pattern and then fitting in the noisier or more complicated areas. Clearly heat travels from the equator up through the Arctic (and Southern) Ocean; how and when that heat moves determines very significant changes we see.
There is so much to see now that all this data is available. It is overwhelming. A person needs to be paid to do it or, like the gentlemen-scientists of the 19th, to be self-sufficient on their estates AND lack TV and video game distractions. (A family looked after by nannies and servants helped them, too.)
Dave X: Yep. I would expect to see the 60-year mode outside the data range; the 260 one, not so much.
HenryP: all x-axes are date, all y-axes are delta temperature in celsius
Zeke: note there is a matching dip in land temps, meaning it was probably physical and not (entirely) measurement problems
I enjoyed your article very much. I especially liked one statement which proves beyond the shadow of a doubt that you have the instincts of a scientist. It is: “We can add another one, even assuming the land temperature measurements are perfectly accurate: cloud feedbacks may operate differently over land and ocean.” I say “fie” on anyone who says Earth has an albedo. There are many varied albedos with many different effects. Unfortunately, climate science has not yet shown itself capable of undertaking studies of them.
It is interesting, and the post that preceeded this too. Hard to explain the divergence though with anything but wild speculation, arguments could be made for and against greenhouse as the culprit. The close sychronicity of previous years would seem to rule out a delay. Also greenhouse warming isn’t new, it’s just said to be enhanced and is present in those previous years. I take it a sea temperature does mean the sea i.e. the water, though a surface temperature is really air temperature at the surface, perhaps the two aren’t linearly connected for a changing greenhouse forcing? Wild speculation….
“First I got the HadSST records from http://www.cru.uea.ac.uk/cru/data/temperature/.”
========================
Weren’t the records from 1945 into the early 70s mal-adjusted due to the “bucket” issue?
http://climateaudit.org/2008/06/01/did-canada-switch-from-engine-inlets-in-1926-back-to-buckets/
Also, somewhere I seem to recall Mr. McIntyre posting an off-hand comment that by a simplistic back-of-the-envelope type undoing of the bucket adjustment, the correlation with Solar improved to approx 80%.
In that second link above, there’s also a nice graph from Thompson et al 2008 comparing SST measurements to proportional UK and US shipping registry, and how the SST correlates to which nation ships were flagged under.
Something very unusual happened around 1950 — that’s nearly an 8-sigma excursion. And I haven’t the slightest clue what it was.
That’s when I came to America.
Does this “model” have any predictive skill whatsoever?
I think not at all.
Correlation does not equal causation.
Oh and why don’t you use the term “convolved Gaussian kernel” as that sounds so techy?
When all that techy term really means is a moving average using a bell curve.
With only half a bell curve populating the start/end of the smoothed time series.
So all smothing functions have end effects, if the low pass filter is carried out to the actual ends of the higher frequency time series, as you have done, no getting around that one, as we have no idea of what the unknown past/future time series was or will be.
Do love that presistence of the ~60 year cycle though, kind of like claiming that Earth’s climate runs in clockwork like fashion, sort of like placing the Earth at the center of the universe and what all.
Your treatment is more akin to astrology than it is to the scientific method.
Nuff said.
If the ≈40% rise in CO2 had a measurable effect on temperature, then current temperatures would be accelerating above trend, no? But they are not. The planet is still warming on the same trend line from the LIA. Anomalies occur, but they always revert to the mean.
Further, the current very mild warming cycle [0.7° – 0.8°C over the past century and a half] is indistinguishable from numerous similar [and often greater and more rapid] warming spikes throughout the Holocene, when CO2 remained low.
Certainly if CO2 caused any more than minuscule warming, temperatures would be rising geometrically above trend. But they are not. Observed temperature rises are fully explained by natural variability, and facts such as the failure of accelerating thermal expansion of the oceans, and numerous other failed predictions by the climate alarmist camp, should make every reasonable scientist question the basic AGW hypothesis – which still remains an evidence-free assumption.
In theory the nuclear testing could have temporarily warmed the stratosphere to push the jets equatorward or make them wave about more meridionally for increased global cloudiness and albedo with reduced solar input to the oceans.
I’ve no idea whether the data supports that though.
Found it….
I expect that he’s done followup since then…so this may well not reflect his current conclusions.
If the last graph is Celsius
there must be a mistake somewhere
Most people (including Anthony Watts) have reported a value of 0.015 degrees C/ annum warming for the last 4 decades
I reported 0.018
http://www.letterdash.com/HenryP/henrys-pool-table-on-global-warming
This includes more stations than currently shown there in the file…
There is no UHIE at sea.
gdn: A high sensitivity to solar is required because all they examine is the TSI directly.
No assesment is made of the Svensmark affect.
No assesment is made of the fact that not all wavelengths change equally during the solar cycle.
Basically, they are looking for an excuse to dismiss anything that isn’t spelled “CO2” as a factor in climate change.
http://wattsupwiththat.com/2011/06/06/earth-fire-air-and-water/#comment-674784
Three great cherry picks.
The first shows several long term time series of temperatures with NO discernible ~60 cycle whatsoever. Go figure.
The second shows a single location, at the top of the Greenland ice sheet, like at 10,000 ft above sea level, as if this were some kind of a true representation of the global temperature time series over the Holocene. And a proxy time series no less, I thought you people abhored paleo reconstructions. Go figure.
The third proports to show the aforementioned ~60 cycle + linear trend, I wonder what the R^2 is on that particular one, surely not even the 0.78 claimed at here. Smooth any time series enough and you’ll get any R^2 you desire, doesn’t make it real or suggest any predictive skill whatsoever. A Clockwork Orange. Go figure.
gdn says:
June 6, 2011 at 9:03 am
“First I got the HadSST records from http://www.cru.uea.ac.uk/cru/data/temperature/.”
========================
Weren’t the records from 1945 into the early 70s mal-adjusted due to the “bucket” issue?
http://climateaudit.org/2008/06/01/did-canada-switch-from-engine-inlets-in-1926-back-to-buckets/
http://climateaudit.org/2008/05/31/lost-at-sea-the-search-party/
///////////////////////////////////////////////
Interesting post. As far as I know, shortly after the introduction of the diesel engine, data entered into the ship’s logs is taken from the engine inlet manifold. Likewise when a ship reports to weather routing agencies (such as Oceanroutes and the like), the data the ship provides to these agencies is that extracted from the ship’s logs, ie., engine inlet manifold temperature.
The depth at which the cooling water is extracted depends on the size, design and configuration of the vessel and in this I include whether the vessel is fully laden or only partially laden or sailing in ballast. That said on deep water crossings, most ships are operated fully laden (for obvious profit reasons), and one nay therefore consider that the inlet manifold temperature is that drawn from about 7 to 13 metres below the surface.
I have pointed out on several occassions that ship’s logs (and hence the data they provide to weather routing agencies) represents typically water temperature drawn at about 10 m below sea level and thus ships are if anything underrecording sea surface temperature and one needs to adjust their temperatures upwards not downwards.
Additionally, whilst I am not saying that this is a wide spread practice, some ships may be deliberately under recording sea temperatures. A number of products carried (Veg Oils, some chemicals) need to be heated during the voyage and the shipowner in effect gets paid for this service. It may therefore be in the interest of the shipowner to say that the sea temperature was so low that heat was required when in practice no heat may have been required or applied because ambient sea temperature was sufficient to keep the cargo warm withiut using bunker fuel for heating purposes (eg in the Indian Ocean, the Gulf, some parts of the Pacific etc). Thus once again, the ship’s logs may be recording a lower sea temperature than the true and proper sea surface temperature.
It therefore appears that the proposed adjustments by the ‘Team’ is the wrong way around. I do not know whether this is out of ignorance not knowing how ship’s record their data, or whether it is a deliberate attempt to ‘cool’ down the oceans post 1940s so that the ‘Team’ can argue that there has been more warming between the 1940s and the introducrion of ARGO.
EFS_junior is arguing with everything just for the sake of argument; I’ve smoked out a crank. He says:
“I thought you people abhored paleo reconstructions.”
First, we are not ‘you people,’ we are mostly scientific skeptics – the only honest kind of scientist. And junior’s statement is, not surprisingly, wrong. Ice core data is real world data. It is the paleo treemometer reconstructions that are on shaky ground. As for the misinformation claiming that ice cores do not show a global correlation… wrong again. Both hemispheres correlate closely in temperature fluctuations.
In fact, AGW remains an evidence-free assumption. Junior doesn’t like it, and neither does he try to refute my basic argument: that the trend line from the LIA remains intact, and there has been no accelerated warming attributable to increased CO2 over natural variability. CO2 may cause minuscule warming, but it is so insignificant that it is unmeasurable. That’s why folks are still arguing over sensitivity.
Ask yourself this simple question. Why does “Climate Science” add “science” to its name? Does Physics, Astronomy, Meteorology, Chemistry, Mathematics, Biology, Medicine? Why is climate science unique? Because Climate Science is no more a science than the People’s Democratic Republic is a democracy.
Start with the phrases “the science is settled” or “the evidence is incontrovertible”. Climate science is unique in this regard among all the sciences. In no other branch of science is the science “settled” or the evidence “incontrovertible”. This is strong evidence that Climate Science is not science at all. If it was, then why is it unique as compared to all other branches of science?
The stones. Bring me the stones.
“No assesment is made of the fact that not all wavelengths change equally during the solar cycle.”
Which completely ignores the photoelectric effect, for which Einstein won the Nobel prize in Physics in 1921. The energy of a photon is not related to its intensity. It is related to is wavelength.
Think of it this way. We are going to shoot you. With a 22 caliber bullet. One we will shoot from a straw using human breath, the other from a gun. Both will be shot from a distance of 1 foot at a rate of 1 bullet per second.
It makes no difference if we fire the bullets from a gun or a straw as to the number of bullets that hit you. That is the intensity of the bullets. The TSI. However, if makes a huge difference whether the bullets are from a gun or a straw as to their energy level.
Now, consider your body temperature. Even if we double or tripple the intensity of the bullets fired from the straw, your body temperature is not likely to change very much. However, if we vary the energy level of the bullets, and fire them from a gun rather than the straw, your body temperature is likely to vary a great deal.
The same goes even if you are firing the bullets into say water, though the direction of temperature change is likely to be reversed. The same intensity of bullets – 1 per second – will have a much greater warming effect on the water temperature if the bullets are fired from a gun (higher energy) than from a straw (lower energy).
Climate Science totally ignores this when they talk about TSI. Thus, Climate Science is non Science. Climate Nonsense.
@ferd berple
“Climate Science is non Science. Climate Nonsense.”
We could call it Climate Séance from now 🙂
ferd berple says:
June 6, 2011 at 11:50 am
Ask yourself this simple question. Why does “Climate Science” add “science” to its name? Does Physics, Astronomy, Meteorology, Chemistry, Mathematics, Biology, Medicine? Why is climate science unique?
I’ve heard of the big bang Theory but I never heard the term AGW Theory. I don’t think they use the word Theory either.
Does UHI explain most, if not all, of the linear rise in land temps since? Or do you need Hansen’s post 2000 “adjustments”? We already know GISS plots from 1998 & 2008 so significant changes: cooling of the 1920-1950 period and warming of the 1990-2000 period.
Bill
ferd berple says:
June 6, 2011 at 12:19 pm
Pretty sure leif knows enough about this..
Where do the two time periods come from (i.e., 62.7 and 259.9 years)? If they come from a physical theory then I think you might have something with this. If from the data then I’m not sure what this says but I don’t think it has predictive capability.
Just like ‘Social Science’, and ‘Political Science’, neither sciences in any strict sense. Once upon a time there was Climatology. What happened to it?
/Mr Lynn
CLIMATE OSCILLATION
(Mathematics is the science of patterns)
Study of the annual global mean temperature anomaly (GMTA) shows the following pattern
1) A 30-years long alternate cooling and warming oscillation of 0.6 deg C and
2) A 30-years warming of 0.18 deg C
This pattern can be validated using the following observed data
Year=>GMTA (deg C)
1880=>-0.22
1910=>-0.6
1940=>0.1
1970=>-0.3
2000=>0.5
http://bit.ly/fizsCE
We start with the GMTA of –0.22 deg C for 1880.
GMTA for 1910 (1880 to 1910 cooling) => -0.22 – 0.6 + 0.18 => -0.64 deg C
GMTA for 1940 (1910 to 1940 warming) => -0.64 + 0.6 + 0.18 => 0.14 deg C
GMTA for 1970 (1940 to 1970 cooling) => 0.14 – 0.6 + 0.18 => -0.28 deg C
GMTA for 2000 (1970 to 2000 warming) => -0.28 + 0.6 + 0.18 => 0.50 deg C
GMTA for 2030 (2000 to 2030 cooling) => 0.50 – 0.6 + 0.18 => 0.08 deg C
Comparison of simple model and observed data
Year=>GMTA (Observed) => GMAT (Model)
1880=>-0.22=>-0.22
1910=>-0.6=>-0.64
1940=>0.1=>0.14
1970=>-0.3=>-0.28
2000=>0.5=>0.5
The above comparison shows excellent agreement between model and observed data.
Conclusion: Based on 130 years of observed data, the annual global mean temperature anomaly is cyclic with alternate 30-years warming and cooling of 0.6 deg C, in addition to an overall warming of 0.6 deg C per century.
Pay no attention to 1950. It was not a glitch in the Matrix. Move along now. Nothing to see here.
Imagine yourself to be an extradimensional physicist. You’ve managed to access a locus of electrical energy in our dimension (wall outlet) but only by very indirect means. You manage to establish that there is an amazingly stable periodicity to the signal (60Hz). After oberving it for a while, you are reasonably confident in predicting the magnitude of the signal at any time for the indefinite future. You’ll probably add a lot of caveats, but simple observation leads to reasonable prediction, even without understanding all the nuts and bolts of the process.
The only thing we lack is, perhaps, a sufficiently long record to bolster our confidence. But I’ll take “uncertain reality” over “fantasy model” any day.
From 194-45 a lot of cities burnt and a lot of oil went into the Atlantic, the North Atlantic especially, and also the Pacific.
The half life of the remains of Hamburg, Dresden, Tokyo, e.t.c. would have been a year to two years.
The oil on water would have stopped evaporation and would have slowed heat transfer.
Just add another frequency or two into the mix, and you can cover the “anomalous” period, too. How about plotting a PSD, so you can see the frequencies where the significant peaks occur directly?
I have often wondered if the SST anomaly in the 1940’s couldn’t simply been due to the fact that most ships were traveling in convoys 1939-45. Ships in convoys typically were organized into columns, which means that most SST measurements would have been of water that had been churned up by several ships, mixing cooler deep water with surface water.
Has anybody looked at the geographical spread of the anomaly? Convoys were not used in the South Atlantic and most of the Indian Ocean.
Numerological cherry-picking.
Curve-fitting of this nature unconstrained by any physical theory to define the frequency of the curves is arbitary and extremely dependent on the vageries of the data.
For instance, if the data is taken from the 1950s, starting at the 6 sigma ‘anomaly’ it would probably be possible to accurately follow the curve with two different frequencies and amplitudes of cosine curve.
In fact small changes in the data would lead to a very large number of possible cosine ‘fits’. But it is unclear this mathematical manipulation would have any meaning or implications for the CAUSE of the warming. You may be matrching inhomogenities in the data caused by changes in measurement method; bucket/inlet/satellite.
Using satellite data on sea level rise is probably the best source of measurement for the actual physical changes that have ocurred globally. The sea level rise is an unambigous reflection of the extra energy that has been absorbed by the climate system over the past decades.
@- Smokey
“Ice core data is real world data. It is the paleo treemometer reconstructions that are on shaky ground. As for the misinformation claiming that ice cores do not show a global correlation… wrong again. Both hemispheres correlate closely in temperature fluctuations.”
Well there are quite a lot of ‘skeptics’ who doubt the ice-core data citing Jaworski(?) and possible errors in CO2 diffusion, pressure leaching etc.
But the other thing is that the North and South polar data do NOT “correlate closely”, except in as much as the Holocene record shows an antiphase relationship, with warming in the Antarctic accompanied by cooling in the Arctic and vica-versa.
depts.washington.edu/isolab/papers/SteigAlley.pdf
“Comparison of climate records from Antarctic and Greenland ice cores shows that the two regions respond asynchronously during millennial-scale climate changes. The apparent out-of-phase relationship between the records has been described as a climate “seesaw” in which cooling in the Northern Hemisphere is balanced by warm-ing in the Southern Hemisphere.”
Izen,
You believe your eyes are lying to you? Obviously there is strong correlation between the hemispheres. Here’s another view of Vostok, EPICA and GISP-2. Obviously they’re in phase with each other.
The alarmist contingent will go to any lengths to try and prove that white is black, evil is good, down is up, and in-phase is out of phase. *sheesh* Cognitive dissonance in action. When is the flying saucer due?
Reliance on UEA. CRU SSIs is a No-No!
I spent some 17 years recording and reporting weather on Merchant Ships, as used by the UEA.CRU.
Their Premisses for obtaining Global Temperatures ( particularly SSTs) and their 1850 -present graph are at best laughable.
Only the World’s major sea lanes have any reliable record of SSTs.There is no record covering almost 50 % of the Oceans for most of the period.
We always recorded the temperatures to the nearest whole degree F. Working out corrections of half a degree is therefore useless.
@-Smokey says:
June 7, 2011 at 7:57 am
“You believe your eyes are lying to you? Obviously there is strong correlation between the hemispheres. Here’s another view of Vostok, EPICA and GISP-2. Obviously they’re in phase with each other. ”
I believe my eyes…
I especially believe that my eyes are incapable of seeing a ~500 year anti-phase relationship between the N and S polar ice cores when the graph is such low resolution that 5000 years is the minimum division.
Try looking at the raw data, or a graph which resolves the ice-cores to less than thousand year data-points, then the ‘antiphase’ or contrary warming/cooling can be seen by everyone but the dogmatically purblind.
Izen,
That’s funny, coming from someone every bit as coginitive dissonance-afflicted as one of Harold Camping’s true believer followers.
If you can post a graph contradicting the graphs I posted, showing a temperature peak in one hemisphere overlaid by a temperature trough in the opposite hemisphere, I’ll start to pay attention. Until then, not so much.
izen says:
June 7, 2011 at 6:57 am
“Curve-fitting of this nature unconstrained by any physical theory to define the frequency of the curves is arbitary and extremely dependent on the vageries of the data.”
Which is why I stated above a PSD should be used to nail down the frequencies to be used in the fit. You don’t have to have a full blown physical theory. But, one does need some reason for picking the frequencies one uses.
If someone will tell me where to get the data, I will give you the frequencies.
Smokey says:
June 7, 2011 at 9:01 am
“If you can post a graph contradicting the graphs I posted, showing a temperature peak in one hemisphere overlaid by a temperature trough in the opposite hemisphere, I’ll start to pay attention. Until then, not so much.”
web.mit.edu/~phuybers/www/Doc/Synchronize.pdf
The graph you want is on page 7.
Izen says:
“The graph you want is on page 7.”
No, that’s the graph you wanted, and probably the best you could come up with. And it still does not contradict what I posted earlier.
Here is another graph showing correlation between the hemispheres.
And I’m still waiting for you to post evidence showing global damage from CO2. Because if there isn’t any harm… then CO2 is harmless, and the central pillar of the wild-eyed alarmist contingent comes crashing down.
RE: tty: (June 7, 2011 at 12:21 am)
“I have often wondered if the SST anomaly in the 1940′s couldn’t simply been due to the fact that most ships were traveling in convoys 1939-45.”
I believe I read a similar explanation somewhere except it said during World War II shipping was diverted out of the usual sea-lanes due to blockades and the threat of submarine attack. This changed the actual region where these measurements were made.
J Stohrs, you wrote, “I generally prefer to use sea-surface temperatures when looking at global trends for several reasons: they have a lower variance, indicating a better stability to short-term perturbations
the surface water temperature is measured directly, eliminating some of the definitional issues of surface air temperature…”
The calculated variance of SSTs is not indicative of the accuracy of the measurements, which is almost certainly no better than about (+/-)1 C. So, use of SSTs rather than surface air temperatures doesn’t get you much. Further, bucket SSTs, which constitute more than half the 20th century record, come nowhere near even that accuracy. So, definitional issues aside, using SSTs doesn’t improve accuracy.
In other news, we are, after all, interested in global average surface air temperature. As the land surface is 30% of the global surface, it seems fitting to include measurements taken there.
This, “Temperatures can go up and down on land like a wagging tail, but the oceans are the dog.” isn’t entirely true either. Oceans do moderate coastal air temperatures, but internal continental temperatures are determined by, among other things, topology. I’ve fit the GISS global average land-station temperatures alone, and the oscillatory part, which I take to indicate world ocean cycles, puts about (+/-)0.1 C in the land surface anomalies. It’s true that the oceans dominate climate inertia, but the analysis is about short term (centennial) fluctuations. The effect of ocean thermal inertia is relatively low-frequency.
You wrote, “However, a linear fit to the secular rise simply can’t be right. It would retrodict an ice age right at the peak of the Roman Empire.” This imposes an incorrect inference on my analysis. It was obviously never meant to be predictive or retrodictive. It was meant to assess the trend between 1880-2010, when industrial CO2 is supposed to be influencing global air temp. To reject the linear part of the fit, because it gives absurd pseudo-predictions at long times, is analytical opportunism. It’s the same mistake, in fact, that Tamino has made. He used it to open the door for analysis, which made use of irrelevant models.
My analysis isn’t a theory of Earth’s climate. It’s an empirical analysis — data-based, in other words — looking for evidence of perturbation in a bounded data set. No more than that was ever represented. Rejection on the basis of an ice-age pseudo-hindcast for the Roman Empire is to abuse a bounded model.
Your third Figure shows that land surface air has warmed more than SST during the 20th century, and you reject the sensitivity analysis on that basis. But let’s remember that the sensitivity is about the relatively short term response of surface air temperature to additional CO2, not the sensitivity of SST. The inertia of the oceans requires a much longer term thermal response. So, it’s no surprise that ocean surface temperatures show lower intensity changes than land air temperatures.
Your first Figure, by the way, shows that you gave equal credence to SSTs measured prior to 1880, when there are very few measurements. The structure of your model appears to depend on the apparent rise in SST between 1855 and 1880. The reliability of temperatures measured during this time — land or SST — are very poor, which is one reason I began my analysis at 1880. You might want to try again starting from 1880 and see whether you get the same fit.
Pat: A very valid point about the linear fit and period of validity. I withdraw my remark about retrodiction; it was ill-considered. As I mentioned in my follow-up post, your linear + 60-year oscillation is an excellent fit for the 20th century.
The main problem with land temps for attribution is that there are so many potential confounding factors, which using SSTs finesses. It also seems likely, and this is just a guess, that there are substantively different dynamics as well.
HadSST coverage goes from 20ish in 1850 to 30ish in 1880. (Percent of the globe, not just the oceans.) You’re right that the record is less complete and less precise the farther back one goes, but the record such as it is agrees with other sources that the 1800s may have been something of a plateau.
None of this impacts what I take to be the point of both our posts, that CO2 didn’t cause the majority of the 20th century rise. Of course, it sure would be nice to know what did!
J Storrs, thanks very much for your generous reply. It’s in the spirit of science and appreciated.
I’ve consulted again, D. E. Parker, et al. (2000) “Climate Observations — The Instrumental Record” Space Sci. Rev. 94, 309-320. According to their Figure 1 land surface coverage in 1850 was about 5%, rising to about 10% by 1880 and 25% by 1900. Sea surface coverage was about 8% in 1850, rising to about 16% in 1880 and 30% in 1900.
There is a similar analysis for land surface stations in J. Hansen, et al. (1999) “GISS analysis of surface temperature change” JGR 104(D24), 30997-31022. But Hansen rests his coverage on his 1987 correlation analysis, so that that anywhere within 1200 km of any given station is covered. By his lights, in 1860, 5% of the southern hemisphere and 30% of the northern hemisphere were covered; by 1880, it’s 10% and 50%, and by 1900, 30% and 70%. These numbers are necessarily generous.
With respect, I still think that the 1850-1880 SST and global anomalies are unreliable.
“Lo and behold, there really is a linear rise above the sinusoid in the land data — which isn’t there in the SST data.”
No , what you see here is what you have already noted but forget about: land temps show more variation.
What the post 1950 section shows is a similar rise to what you have in sea data but bigger, a larger variation of the same nature.
To make any comparison you need to do the same fitting process for the land data and compare the two. Simply fitting to sea data and then noting that land is different is just stating the obvious. Much of what you are arbitrarily calling a “linear rise” is simply a question of a scaling difference.
The closeness of the fit with the two cosine terms is remarkable though you need to be careful when your data period is only about half a cycle. Lots of things bend around in a similar way to half a cycle of sine a wave but the fit is very good.
Could you post the complete function of those cosines rather than just the period?
It would also be interesting if you would explain what you used to do the fits. Just hard work by hand or some fitting algorithm?
How are you filling the end of the gaussian filtered data? You should loose the first and last ten years when doing any kind of averaging since the data is incomplete. How are you padding to get a result over the full period?
Pat: Thank you in turn; it’s appreciated. The coverage figures I mentioned were from the same data files as the temps, from http://www.cru.uea.ac.uk/cru/data/temperature/. They *claim* the 1850’s are accurate to 0.2, but frankly I don’t believe them … so we may as well let it drop; the existence of the 1890 knee isn’t particularly important to either of our arguments.
J. Simpson: I fit the function
p[0]*cos(2*pi/p[1]*x+p[2]) + p[3]*cos(2*pi/p[4]*x+p[5]) + p[6]
where p is a parameter vector and x is the vector of times (just year numbers)
to the temperatures using scientific python’s scipy.optimize.leastsq optimizer
(see http://docs.scipy.org/doc/scipy/reference/generated/scipy.optimize.leastsq.html)
The resulting parameters p are [ -1.41458960e-01, 6.27587010e+01, -1.93192077e+03,
-2.91801347e-01, 2.60917034e+02, -1.88646701e+03, -8.18030465e-02]
This tells us that the cosines are period 62.7 with a minimum at 1931.9, and period 260.9 with a minimum at 1886.
(The numbers are slightly off those above since I didn’t bother to take out the notch for this reply!)
For a quick and easy gaussian endpoint straightener, divide your convolved series by the result of convolving a series of 1s with the same (normalized) gaussian.
J Storrs, about error, CRU and now UK Met implicitly claim that all measurement errors are random and cancel out in their averages. The only real errors they acknowledge are sparsity of coverage and methodological and instrumental changes. The claim of otherwise random errors does not stand up to examination (pdf download). It’s my very considered view that the global air temperature anomaly series is climatologically useless, including SST.
Capture Conc: DEICERS from Heavy Duty DESALTERS & thereby GROW more ICEMASESS in POLES & HIMALAYAS. That could be lead to AIR-CONDITIONING OF MOTHER EARTH
ferd berple says: June 6, 2011 at 11:50 am
“Why does “Climate Science” add “science” to its name? “
I’m chuckling because Tim Ball says when he got his degree the field was called “Geography”. He was studying temperature records before some of these alarmist “scientists” were born.
Excellent question why they are using phrases like “the science is settled” – don’t other fields just debate their science?
Gore, Suzuki and the IPCC say that the “science” of climate change is “settled”. Let’s think about this:
1. Science or Art?
Science determines parameters and their interconnections, ultimately arriving at “predictions” that make or break the theory that binds observations and results together in a causitive way. Climate “science” works towards “scenarios” or “projections”; Pachauri and others vigorously deny that they create predictions. So their “climate science” is not science, but an analytical type of art. Climate scientists get a sense of how things are, only, and feel their way forward with that gut understanding.
2. Settled or not?
In 1990 the IPCC had a range of scenarios higher than the 2007 IPCC report. In 1990 the study was relatively new, at least with its CO2 as prime driver, so it is reasonable that there would be adjustments to their scenarios in 17 years. However, in 2007 the science is said to be “settled”, and certain to more than 95%. If that were the case, then the scenarios would have been reduced to a result, albeit with an error range. That has not happened. We still have a catastrophic and a virtually nothing different from a continued recovery from the LIA. That means that the climate scientists still haven’t determined what the prime controlling parameters are and what the power of each is. If CO2 were determined to have a 3.75 W/m2 power with a 3.0X water vapour multiplier, then we would be told that in 2025 it WILL be X, and in 2100 it WILL be Y. But this does not yet happen: the scenarios given in 2007 by the IPCC are still as vague and multi-resulting as before. So the science also isn’t “settled”
It takes little thought to see that CAGW is based not yet on science and not yet on anything settled to a 95% certainty. Scenarios that describe a world in 39 years (2050) from what we had yesterday to an ecological disaster that drowns a billion people world wide in multi-meter sea rises and starves to death millions more in continent sized famines are so different that it is hard to understand anyone with the thinking ability of a well-trained chimpanze to believe the climate scientist understands why things happen and what they are going to do even in the near term. Belief beggars the mind, or perhaps impoverishes the mind is a closer concept.
Think of this: if Newton had said he understood the principles of gravity, and that the principles were “settled”, and he would throw a ball into the air and could be certain that it would go higher for a while and then either fly away into space or fall down again some time later, but was going with a fall-down-later scenario with a “later” time frame of 30 seconds to 5 minutes, would we be honouring Newton today?
Dunno if anyone is still following this, but Hadley have revised the SST record in a way that takes out the “notch” — see http://climateaudit.org/2011/07/11/more-misrepresentations-from-realclimate/