Guest post by Willis Eschenbach
Bob Tisdale has discussed a variety of issues with the hemispheric and basis-by-basin Levitus summary of the ARGO data in his excellent post here on WUWT. I wanted to take a larger look at at the global ocean data, to provide it with some context. After following a variety of blind paths and dry holes, I arrived at Figure 1. This shows the Levitus data, along with several datasets for both the sea surface temperature (SST) and the land surface air temperatures.
Figure 1. Three land surface air temperature datasets, three ocean surface temperature datasets, and two measures of the deeper ocean. Datasets from KNMI, except the Levitus ocean data. Levitus data have been converted from ocean heat content values to temperature values.
Unfortunately, we only have pentadal (5-year centered average) data for the deeper ocean layer from 1955, no annual data for the deeper layer is available before 2005. So I have shown the other data as pentadal averages as well, so that they can be compared directly. Now, I have no profound conclusions from this, but there are some curiosities about these results.
The most obvious oddity involves the sea surface temperature data. Two of the datasets, the ERSST and the HadISST, are quite similar, but are offset over much of their length by an amount that varies in an odd stepwise fashion. In particular, they diverge significantly in the period 1997-2001. They have the same small peaks and valleys, but the land is going up while the sea temperature is dropping. Figure 2 shows this in more detail:
Figure 2. Sea surface temperatures (SSTs) from three different sources. The vertical axis scale is different from Figure 1.
On the other hand, Figure 2 also shows that the ICOADS dataset runs almost exactly in parallel with the HadISST data up until 1997, when it shifts gears and goes up to agree with the ERSST dataset.
I have absolutely no idea what happened in 1997, or in earlier periods, which allowed the three datasets to vary so much. Always more questions than answers.
The next oddity involves the changes in the land and ocean surface temperatures. Figure 3 is like Figure 1 but leaves out the sub-surface temperatures:
Figure 3. Three land surface air temperature and three ocean surface temperature datasets.
The oddity here is two-fold: what happened around 1977 or so, and what happened around 2002 or so? From 1977 on, after twenty years with no significant land or sea temperature change, both land and sea temperatures start to rise. In addition, the land temperature rises much more rapidly than the SST. Then around 1998, SSTs start to level off, and they peak in 2002 and start to fall. The land temperatures start falling shortly thereafter. Why, on all counts?
Now, I don’t know the answer to these questions either. However, in this modern world there’s a term called a “WAG”, which means a wild-assed guess. However, scientists don’t provide those. Instead, there is a refined version called a “SWAG”, or a scientific wild-assed guess.
So here’s my SWAG about what we’re seeing here. I think at least some of this is the effect of the Pacific Decadal Oscillation, or PDO.
The PDO is a large-scale reorganization of the flow of the North Pacific Ocean. I think that, like other large-scale patterns such as the El Nino/La Nina alterations, these all function to regulate the temperature. It is obvious that one of the two major patterns (positive or negative PDO) must be more efficient than the other one at cooling the planet. The transfer of heat via the oceans from the equator to the poles is one of the two major pathways by which the tropics moves heat (the other is via the atmosphere). One of the two PDO states must be better at cooling the planet.
I hypothesize that this alteration between PDO states is one of the ways by which the planet maintains such a regular temperature. Unfortunately, I have no idea how to support that hypothesis using observational data.
A final oddity is the decoupling of the land temperatures from the ocean temperatures. Figure 4 shows a longer version of the same data, this time extending back to the 1870’s:
Figure 4. Long-term land air temperature and sea surface temperature records, expressed as an anomaly around the 1900-1980 average.
The oddity to me in Figure 4 is that since about 1974, the land temperatures have been rising much faster than the sea surface temperatures. The SST records and the land temperature records run quite close to each other up until about 1975 or so, but after that land temperatures have been rising much more quickly, while the sea surface temperatures (and to a greater extent the sub-surface temperatures) have not followed suit.
Once again, I’m out of explanations for the decoupling of the temperatures. Clearly it’s not CO2. Urban heat islands? Aerosols reducing the clouds over the land? I have no idea. All suggestions welcome. That’s the beauty of settled science, there are always unexplained questions to
Best regards to everyone,
w.
THE DATA
Levitus provides two different global pentadal datasets. One covers the layer from 0 to 700 m depth, and the other covers a thicker layer, from 0 to 2000 m depth. I wanted to see what was happening in the “missing link”, which is the data covering the deeper layer, from 700m to 2000m depth.
The good news is that since we are dealing in oceanic heat content, the heat content of the lower layer is simply the difference between the two datasets.
My spreadsheet with the results is here.
Willis Eschenbach says: “I don’t trust any of the datasets back much beyond 1900, and the CruTEM dataset doesn’t even start until 1896. So I’d be very reluctant to say anything about that pre-1900 period.”
I don’t trust the early data either, but CRUTEM4 data extends all the way the back to 1850. At the KNMI Climate Explorer, just below the coordinates is a “demand at least” ‘x’% of the data” field. The only reason you’re losing the early data is the 30% default setting on that field. Set it to 1 or zero and you’ll get all of the data. Of course, you have to keep in mind how little data there is, but it’s there.
Willis Eschenbach says: “So how can the recent land increase be due to “a worldwide warming of the oceans” as your citation claims? That doesn’t make sense.”
Please clarify whether “recent” is after 1997 or after the 1970s–thinking of annual or monthly data. That is, sea surface temperatures flattened after 1997 but land surface air temperatures did not. Just trying to limit the time period to what you want to discuss.
Regards
PS the ‘linear trend’ would be the same as taking the average of my rate of change plot. In view of the ups and downs in that data, how relevant to you feel the arbitrary decadal periods you chose are and how good a choice are they as a period over which to take a mean?
That’s a rhetorical question, I’m sure you get my point.
😉
http://climategrog.wordpress.com/?attachment_id=219
PPS, taking the three ‘bumps’ since 1975 ( which seems to be like a neutral point in the curve) I’d say all three plot lines are about even. Noting of course that BEST has been scaled down by a factor of two. So yes, land changing twice as quick as sea.
However, this does not seem atypical of the whole pre-war period 1860-1945 either though that is closer to mean of zero.
The point is that the more rapid warming of the later period seems to be in line with land being twice as volatile and is not a special effect or a “decoupling”.
Willis says: “The subsurface oceans have been warming fairly steadily since about 1900.”
The NODC OHC data you’ve presented starts in 1955 (or 1957 for the pentadal data), so your statement confuses me. But I recall a recent paper that extended the 0-300 meter data back to 1900 and if memory serves, it also had the warming from the mid-1970s to present, and the flat or cooling period from the early 1940s to the mid-1970s, and an early warming period up to the mid-1940s.
Please clarify.
[My error, moving too fast. I meant 1957. Good catch, thanks. -w.]
William Astley says:
May 6, 2013 at 9:13 am
1) Low level clouds have a higher albedo than cirrus clouds and hence reflect more sunlight off into space which explains why an increase in low level clouds cools the planet while an increase in high level clouds warms the planet.
So when sun bathing why do I feel cooler when a high level cloud drifts across the sun?
I may reveal my ignorance by asking this question, but wouldn’t land temps (which are air temps about 4-6 feet off the ground, right?) warming faster than ocean surface temps be a possible result of CO2-based warming? I understand that down-welling lR is unlikely to have much direct heating impact on the ocean, but it should have an impact on air, right? So, land (air) temps increasing faster than ocean (water) temps post 1970 sounds consistent with the AGW hypothesis. I’m agnostic on the AGW hypothesis — I’m just trying to understand how this data might be interpreted.
What further confuses me about the terms “ocean” and “land” temps terminology is that I should think the discussion would be about “air” temps (over land, over water, and over all) and “ocean” temps.
If I’m really confused here (quite likely), help me get un-confused. Thanks.
Willis: I bought an IR thermometer while in AZ during APRIL. I took it with me as I would travel up and down the dry river bed trail near my Mother’s double wide…A length of about 15 miles up and down. I’d “shoot” walls, buildings, ground, sky…and PLANTS. What I found MOST interesting was that I could find certain objects or areas to observe and they would match the ambient, shaded thermometer measurements fairly accurately. AS SOON as you got anywhere near a solar exposed surface, ZING….10 to 20 F higher than ambient air. HOWEVER, the GREENERY in the dry river bed, ALWAYS measured 10 to 15 F LOWER than the ambient temp. STRONG IR absorbers I will admit. But brought up some interesting thoughts about surface TEMP measurements, placement of instrumentation, local IR balances, etc. I’m more and MORE dubious of the validity of concept of “average temperature” . I think it is a completely BOGUS number with no real significance.
Most of the land temps have been “corrected” in the warming direction. Early 20th century temps have been adjusted in the cool direction and post 1945 temps have been gradually adjusted in the warming direction. Steven Goddard (and others) have sites showing this.
Uncorrected land temperature records for the 20th century show no significant warming globally.
http://www.woodfortrees.org/plot/best/scale:1/plot/rss-land
Shows a realistic view of the land data. The satellite data are plotted on a second line showing that the “BEST” data are basically fiction.
There are old sources of data that show 1930s temps were warmer than current temps.
The entire AGW story is not about temperatures, it is about scientific fraud due to politics.
BTW nice post by Peter Axlac
I grabbed 0.5 as a quick SWAG that seemed to match up the land and sea data. It is also roughly the ration of the specific heat capacities of the two (dependant upon how wet your ‘land’ is).
Now rate of change of temp is a measure of power. So land showing twice the rate of change compared to ocean temps would be about right for how the two would respond to the same power input ( or “forcing” in climatology jargon ).
Some further thought may reveal why this ratio does not seem to be the same during the cooling period 1945-1975 when it seems closer to 1:1.
Bob Tisdale says:
May 6, 2013 at 10:29 am
My error, moving too fast, posting on a previous break. I meant 1957. Good catch, Bob, thanks.
w.
In reply to
Kelvin Vaughan says:
May 6, 2013 at 10:43 am
William Astley says:
May 6, 2013 at 9:13 am
1) Low level clouds have a higher albedo than cirrus clouds and hence reflect more sunlight off into space which explains why an increase in low level clouds cools the planet while an increase in high level clouds warms the planet.
So when sun bathing why do I feel cooler when a high level cloud drifts across the sun?
William:
All clouds are high from the perspective of a person on the surface of the planet. It is likely difficult to determine just by looking at the cloud to determine its height.
The cloud which makes it cold when you are sun bathing is a low level cloud.
Attached is a picture of a cirrus cloud.
http://ww2010.atmos.uiuc.edu/%28Gh%29/guides/mtr/cld/cldtyp/hgh/crs.rxml
What you are probably thinking of is a stratus cloud.
http://nenes.eas.gatech.edu/Cloud/Clouds.pdf
This is an interesting review paper for those who are interested in the global electric circuit and how it affects cloud formation and climate. As noted, how the sun modulates planetary cloud is more complicated than GCR is high, more clouds. This paper also explains why there are specific regions that are more affected by solar magnetic cycle changes.
http://www.utdallas.edu/physics/faculty/tinsley/Role%20of%20Global%20Circuit.pdf
The role of the global electric circuit in solar and internal forcing of clouds and climate
Reports of a variety of short-term meteorological responses to changes in the global electric circuit associated with a set of disparate inputs are analyzed. The meteorological responses consist of changes in cloud cover, atmospheric temperature, pressure, or dynamics. All
of these are found to be responding to changes in a key linking agent, that of the downward current density, Jz, that flows from the ionosphere through the troposphere to the surface (ocean and land). As it flows through layer clouds, Jz generates space charge in conductivity
gradients at the upper and lower boundaries, and this electrical charge is capable of affecting the microphysical interactions between droplets and both ice-forming nuclei and condensation nuclei.
Four short-term inputs to the global circuit are due to solar activity and consist of (1) Forbush decreases of the galactic cosmic ray flux; (2) solar energetic particle events; (3) relativistic electron precipitation changes; and (4) polar cap ionospheric convection potential
changes. One input that is internal to the global circuit consists of (5) global ionospheric potential changes due to changes in the current output of the highly electrified clouds (mainly deep convective clouds at low latitudes) that act as generators for the circuit.
The observed short-term meteorological responses to these five inputs are of small amplitude but high statistical significance for repeated Jz changes of order 5% for low latitudes increasing to 25–30% at high latitudes. On the timescales of multidecadal solar minima, such as the Maunder minimum, changes in tropospheric dynamics and climate related to Jz are also larger at high latitudes, and correlate with the lower energy component (1 GeV) of the cosmic ray flux increasing by as much as a factor of two relative to present values.
Also, there are comparable cosmic ray flux changes and climate responses on millennial timescales. The persistence of the longer-term Jz changes for many decades to many centuries would produce an integrated effect on climate that could dominate over short-term weather
and climate variations, and explain the observed correlations. Thus, we propose that mechanisms responding to Jz are a candidate for explanations of sun–weather–climate correlations on multidecadal to millenial timescales, as well as on the day-to-day timescales analyzed here.
‘I grabbed 0.5 as a quick SWAG that seemed to match up the land and sea data. It is also roughly the ration of the specific heat capacities of the two (dependant upon how wet your ‘land’ is).
Now rate of change of temp is a measure of power. So land showing twice the rate of change compared to ocean temps would be about right for how the two would respond to the same power input ( or “forcing” in climatology jargon ).
Some further thought may reveal why this ratio does not seem to be the same during the cooling period 1945-1975 when it seems closer to 1:1.”
I believe over time it comes out to 1.6:1 and yes its related to the specific heat capacities.
Somewhere around here I have a presentation on this and interestingly enough climate models replicate this system metric
I think it has been demonstrated that the surface instrument temperature record has about 0.5 degrees C of warming biases built into it. If you back out the warming biases the divergence disappears. Isn’t that the most likely explanation?
Since 1975, the increase of forcing due to Co2 is around one watt per square meter. This is equivalent to around 2600 kW per square mile or 3500 horse-powers per square mile. The energy consumption in the few square miles around a station could easily match the increase due to Co2. And we don’t even talk about the snow melting on the pavement when it is -5C outside.
RACookPE1978 says:
May 5, 2013 at 8:56 pm
“Willis: I’m surprised you missed one very fundamental difference between the land-based record since 1970, and the sea-temperatures since 1970: CO2 itself IS a part of the increase in land temperature change because of albedo: greater plant growth earlier in the season over larger land areas WILL darken the plant, and that lower albdeo WILL tend to heat up the air masses flowing over the land. Look at desert (rocky) land thermometers? have they gone up as much a wetter, more plant-friendly areas? If EVERY plant on the face of the planet is growing 15 to 27% faster, greener, higher, taller, wider and more brushy, is not less solar energy reflecting back from previous light-colored rocks, dirt, and grassland?”
Vegetation does not get hotter than bare rock just because it is ‘darker’. It is common knowledge among glider pilots that woods and water will NOT give you ANY lift compared to open fields, drained land and hard man made surfaces. Heat will be stored in woods and lakes but this will provide only very week lift at the end of the day once the sun has weakened and the heat given off by surrounding areas has dropped off and only for a short period. I have never ever felt a leaf or any vegetation that is hot to the touch as opposed to walking bare foot on open sand (light in colour), tarmac (dark in colour). In addition the worlds hottest temperatures have been recorded in deserts, not jungles, and in the case of Death Valley there are areas of salt, which is white!
I speak from my own experience either looking for that lift, which means heat, or trying to get to that ice cream without shoes.
Albedo is not a useful measure when an objects thermal characteristics are not taken into to consideration but my guess is that is the quality of the data fed into climate models.
‘murrayv says:
May 6, 2013 at 1:06 pm
I think it has been demonstrated that the surface instrument temperature record has about 0.5 degrees C of warming biases built into it. If you back out the warming biases the divergence disappears. Isn’t that the most likely explanation?”
No see UAH
I looked into this a year or two ago.
I blame Russians, in late 60s and the early 70s there was cold war etc, science was preoccupied with the Jams Hansen’s promoting of the oncoming ‘ice age’; that meant a vary bad scenario for the Soviets, so all of their official reports were showing higher temperature rise than rest of the known ‘universe’, so the proletariat would be reassured.
http://www.vukcevic.talktalk.net/69-71.htm
Do I have any proof that temperatures were doctored?
No, but nature isn’t schizophrenic either. 🙂
http://journals.ametsoc.org/doi/abs/10.1175/2011JCLI3893.1?journalCode=clim
https://ams.confex.com/ams/19Fluid17Middle/webprogram/Paper226726.html
http://onlinelibrary.wiley.com/doi/10.1029/2007GL029755/abstract
WIllis
IMHO – Increased urbanization which goes hand in hand with increased food production, both meat and grain. Growing cities need water which must be drawn from somewhere nearby (consider the Colorado river and Owens lake) and food production needs both drained land and water at the same time. From the 1970s onward there has been an increase in grain and meet production as better agricultural methods and techniques have been found. The term UHI is limiting and encourages an incomplete view. On needs to not just look out the window but go out side and observe otherwise the lazy person will consider UHI is a phenomena that stops at the city limits.
Land that is open to the sky will dry out quicker than that covered in vegetation. Once dried out it will warm up even quicker. Land drainage and water extraction has only increased since the 1960s.
Meanwhile, back at the ranch.
http://www.telegraph.co.uk/topics/weather/10040040/Mystery-fog-ruins-Bank-Holiday-break-for-thousands-of-beachgoers-as-it-engulfs-south-coast.html
Greg Goodman says:
May 6, 2013 at 10:16 am
I put them out as numerical support for what I can see without numbers. This is that the trends diverge around 1970 or so.
I said exactly what I did and why, which was because all I had was pentadal sub-surface data. If you prefer a gaussian average, which doesn’t invert anything, here you go:
This shows the annual data, along with the gaussian average, for the period of overlap of the four datasets.
As you can see, the choice of smoothing methods makes little difference. The oddity is still the differing trends of the land and ocean records around 1970. How come?
w.
‘As you can see, the choice of smoothing methods makes little difference. The oddity is still the differing trends of the land and ocean records around 1970. How come?”
see the papers I linked. the topic is land ocean constrast. there is a bunch of work on it.
here
http://www.inscc.utah.edu/~reichler/6030/presentations/Chris_OceanLand.pdf
I’m still looking for the workshop video on this topic that I posted a long time ago here at WUWT
But the paper above covers some of the issues
UAH and RSS have much less differential between Land and Ocean temperature trends than the above trends show..
Land is increasing faster than the Ocean by only 0.06C per decade in UAH and 0.08C per decade in RSS. They are also very similar over the time period.
Why it would be more than double these values in BEST, Hadcrut, etc. over the same time period, I don’t know. (Well it is probably from the adjustments and UHI I imagine).
http://s3.postimg.org/rtgo1oqzn/UAH_RSS_Land_Ocean_Differential.png
Bill Illis says:
May 6, 2013 at 4:35 pm
UAH and RSS have much less differential between Land and Ocean temperature trends than the above trends show..
Land is increasing faster than the Ocean by only 0.06C per decade in UAH and 0.08C per decade in RSS. They are also very similar over the time period.
###############
From will’s chart it looks as though the land (at the surface) is warming .16C faster than
the ocean. At the troposphere where there is no UHI, we see the differential as .07C/decade (UAH and RSS). we leaves about .09C/decde of warming differential to explain.
Lets call that 0.1C just to make it easy.
This differential could be due to.
A) some process to be defined.
B) microsite bias
C) UHI bias.
My take away from this is that we have a good first order estimate of the upper limit of the combination of UHI bias and microsite bias. Assume that A is zero ( until somebody steps forward to explain the difference) and we are left with B+C being less than 0.1C per decade.
This is important for folks to recognize because a bias this small will be and has been very difficult to detect in a non controversial manner. In our UHI study, for example, the 2 sigma value was around .2C decade. Basically, the UHI bias is hard to detect for S/N reasons.’
UHi and microsite real? yup. Easy to detect given all the other drivers? nope. Zeke has managed to find something around this order of magnitude (lessthan .01C) in the US and together we found something around .05/decade world wide, unpublished so FWIW.
Steven Mosher says:
May 6, 2013 at 3:34 pm
Thanks, Steven. I’ve looked at all the papers you linked, I think. There were four of them. None of them (as far as I could see) addresses the issue of the change in land minus ocean starting in ~ 1970. Prior to that, overall the two moved roughly in concert.
After that, however, the land has gone up much more than the ocean. Not one of your citations addressed that … so I’m still in mystery.
Let me add that all of them contain far too many model results, and far too little observations. For example, the abstract to one of them says:
I’m sorry, but my graph of the differences above shows nothing of the sort … and nobody’s come along to say my results are wrong. Let me give it again:
There is no “time-invariant” relationship there as they claim. Indeed, it is precisely the CHANGE in the relationship that is of interest. But they bypass that question entirely, roll right on past looking at the observations, and immediately fire up the good old computer model and start discussing model results … and regarding model results?
Frankly, Steven, I don’t give a damn.
Models are of little use until we understand the actual observations and the phenomena. Let’s not get ahead of ourselves here. Observations and theory first, and then once the theory is established, THEN the models can help us TEST the theory.
But they cannot understand the reasons for the change for us, we have to do that ourselves.
Now, you’ve claimed that this issue has been discussed in the literature. But sadly, I find nothing in any of your citations that discuss this at all. Do you have a citation to a discussion what happened in the 1970s? That’s the oddity I pointed out.
Thanks for all the ideas,
w.