Guest Post by Willis Eschenbach
Like Jason, I proceed into the unknown with my look at the Argo data, and will post random notes as I voyage.
Come, my friends, 'Tis not too late to seek a newer world. Push off, and sitting well in order smite The sounding furrows; for my purpose holds To sail beyond the sunset, and the baths Of all the western stars, until I die.
I have no great insights at this point, just some interesting results. Thanks to a commenter who pointed me to where to get the Argo data in one block. It’s at the Asia-Pacific Data-Research Center.
I downloaded it, and I’ve looked first at the file containing the surface data. It’s where I swim, so it’s the most interesting data to me. Figure 1 shows all Argo measurements of the ocean surface temperature taken to date.
Figure 1. All Argo ocean surface temperature data. There have been 696,872 Argo measurements to date of the ocean surface temperature.
So far, so good. The results look real, which is always good to see, it means I’ve graphed them up properly. You can see the warm ocean along the coast of Europe, for example. But there is one curiosity about the Argo data.
Here’s the oddity. I took the data arranged by latitude as shown in Figure 2. I averaged it by 1° latitude bands, and then took an area adjusted average to give a global mean. The mean is 19.7°C ± 0.02 (95% CI).
Figure 2. All Argo ocean temperatures, sorted by latitude. NOTE: several people commented correctly below that I had not included the variation in ocean area by latitude band in the calculations. They are correct, I was wrong, and the actual corrected 60N-60S average is slightly higher, at 19.9°C.
Note that there is an obvious upper limit to the ocean temperatures, the “flat-top” on the graph at just above 30°C. No matter how much incoming solar there is, the ocean doesn’t get any warmer than that. This provides a “cap” on how hot the ocean can get. Above that temperature, any extra incoming energy is converted to latent and sensible heat, rather than warming the surface.
But I digress, that part’s just interesting. It’s not the curiosity.
The curiosity is the other ocean data sets give the following values for the average ocean surface temperature 2000-2011:
Hadley Center HadISST1 60N – 60S: 20.5°C ± 0.02°C (95%CI)
Reynolds Optimally Interpolated SST 60N – 60S: 20.4°C ± 0.02°C (95%CI)
NCDC Extended SST 60N – 60S: 20.3°C ± 0.02°C (95%CI)
The curiosity is that the Argo average ocean surface temperature data is significantly cooler than the other datasets, half to three-quarters of a degree …
Always more to learn. I do love real data. Look how much colder and more uniform the Southern Ocean is than the northern oceans, for example. Fascinating stuff.
Best to everyone,
[UPDATE]
The data I used is available at the website listed above, identified as “Near-real time Argo profile data interpolated on standard levels”. It’s the largest file on this page, 895 Mb, titled “Argo_TS.tar”.
The info sheet detailing the arrangement of the data is here.
It’s a tarball containing all of the depth files, one for each layer. The one I used was the zero depth file, “Argo_TS_0000.dat”. I downloaded them all, because I wanted the full set. If you only want surface temps you can download just that one file.
To read it in once it was downloaded (in the “R” computer language), I used:
depthcolumns=c("Longitude", "Latitude", "Level", "Depth", "Julian", "Temperature", "Salinity", "Potential Temperature", "Potential Density", "Dynamic Depth Anomaly", "Spiciness", "Extrapolation", "Error Temperature", "Error Salinity", "Error Potential Temperature", "Error Potential Density", "Error Dynamic Depth Anomaly", "Error Spiciness", "Ocean Code", "Region Code", "Argo Float ID", "Cycle Number", "Dynamic Depth", "Dynamic Depth-2")
depthwidths=c(9, 9, 3, 7, 10, 9, 9, 9, 9, 9, 9, 2, 11, 11, 11, 11, 11, 11, 2, 3, 8, 4, 9, 9)
depthinfo0=read.fwf("/Users/willis/Argo_TS/Argo_TS_0000.dat",depthwidths, col.names=depthcolumns)
You’ll need to change the filepath in the final line to wherever you have put the “Argo_TS_0000.dat” file.
w.
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ugh, very late, forgive the typos.
Real data is the last thing you can find now.
I’m curious about the area adjusted average calculation. I take that as meaning the average of all samples within a given band is calculated as a start. As bands are not all of equal area (equator the largest, outer most smallest) each band’s average contributes to the global mean in proportion to its fraction of the total area.
But, those bands contain land mass (each different) within them which needs to be subtracted from their raw area (sea + land). Is this accounted for?
@Willis Certainly there are areas which are very coherent. But nature loves edges, and way out in the middle of the ocean, no land in sight, you’ll come on a current line. On one side of that line may be warmer blue water, and on the other side of that line may be colder, greener water … not coherent in any sense of the word.
What you describe seems to me the ocean equivalent of “weather.” On land it involves the interfaces of great 3D air bodies rolling past each other as we groundlings experience only a 2D edge of it. A sailor with a thermometer is seeing the weather of the ocean as great 3D bodies water negotiate their passing and mixing.
I remember camping in a canyon below a plateau, the night peaceful and quiet. Then you first hear a great rushing of wind for many seconds while all is still around you. Then a 50 mph gust blows your tent over and is gone 20 seconds later. In 3D a great horizontal “rotor” spins up at the canyon rim, and it moves down the slope much slower than its spinning body. A fast wind moving slowly.
JJ;
the non-overlap of 95% confidence levels indicates, IMO, two things: the bands are too narrow (i.e., cofidence is overstated), and the entire median estimate is improperly or incompetently derived.
Such forgiving banding is characteristic of the soft pseudo-sciences, in any case. No self-respecting physicist would get within several sigma of them.
Did you get your data from here ?
http://www.usgodae.org/argo/argo.html
If not, why ?
go to the Argo home page at the U of San Diego, and use their link(s) to get data.
It’s a very nice analysis, Willis! Still, I don’t think that these are paradoxes or contradictions that you’ve observed. See e.g. this article for some comments of mine:
http://motls.blogspot.com/2012/02/willis-eschenbach-and-argo-on-warmest.html
“Mike says:
February 9, 2012 at 6:27 pm
Latitude graph looks too cold on the North side. There aren’t any waters at 40 degrees north under 3 degrees, and you even have some hovering around zero.”
There are at least two such areas: the Black Sea and the waters around Korea, the Vladivostok Area and Hokkaido. These areas even have fairly extensive sea-ice in winter.
Also the argument that missing shallow areas explain the temperature anomaly ignores the fact that there are extensive areas of shallow cold seas between 60 S and 60 N as well: The Baltic, The North Sea, the shallows around Ireland and New Foundland, most of Hudson Bay, most of the Sea of Okhotsk and the shallows off Patagonia just to mention the most important ones.
Wikipedia says
Argo data result errors
During 2006, the Argo Network was thought to have shown a declining trend in ocean temperatures. In February 2007, the author of the paper (Josh Willis) discovered that there were problems with the data used for the analysis. Many references exist to the uncorrected data results despite Josh Willis’ published correction in 2008: many articles and arguments still use and promote the uncorrected data results from 2006.
Wiki’s a bit coy about the reason for, and the nature of, the “corrections” – but, reading around, it seems they were made to bring the Argo results more in line with previously modeled data.
Are the data you’re using really “raw” data Willis – or have they been “rationalised” in line with the well established principles of climatology?
DocMartyn says:
February 9, 2012 at 6:47 pm
according to your figure the Mediterranean is about the same as the North Sea and North Atlantic.That is, as the English say, bollocks.
The Gulf stream is also missing…
====================================
We’re clearly looking at different maps – by my geography the North Sea is the bit “just to the right” of the British Isles and is all white – presumably unmeasured as it’s too shallow – compared with a beautiful yellowy-red for the Med. The North Altantic shows slightly cooler than the Med (in gold rather than yellow), presumably thanks to the apparently missing Gulf Stream – which in reality is clearly visible as a yellow-gold triangle running from Iberia to the Eastern seaboard to North West of Scotland and providing significantly warmer temperature than for any other oceans at the same latitude.
This graph
http://www.vukcevic.talktalk.net/AOT.htm
may look a bit of a clutter, but it does tell the importance the ocean currents play in distribution of temperatures, at least in the Atlantic Ocean.
Philip Bradley said:
February 9, 2012 at 5:45 pm
“The flat top of ocean surface temperatures in the tropics is interesting. The atmospheric temperature above the ocean surface is what controls the transfer of heat from the oceans to the atmosphere. And this says to me that there is a limit to atmospheric tropical temperatures. Release more heat from the oceans and all that happens is it gets transmitted to space faster.”
I’ve long thought that since the thermal capacity of the oceans dwarfs that of the atmosphere, any TSI variation (both rises and falls) would be mopped up largely by the oceans. But the flat cap tells us that beyond 30C additional Joules go to latent heat of evaporation. To coin a phrase, Warmer Water Wreaks Wetter Weather. This must be very familiar territory to meteorologists! More water vapour leads to more clouds leading to higher albedo and – hey presto – we have a negative feedback loop regulating the climate. Which shouldn’t surprise us for a planet with a 4500 million year track record.
Apocalypse postponed. As the Beatles sang, “Li li li li life goes on” – the denialist #@ur momisugly$£#’s!
The cooler, more-evenly distributed temperatures of the SH (as a whole) could be attributed to them simply being larger and less obstructed by land masses. It takes less energy to generate and to maintain currents with less obstruction.
Take into account where those currents happen and where the SH absorbs nett solar energy which is subsequently distributed by the currents. It is a “chaotic” system governed largely by uncertain boundary conditions. By definition; impossible to calculate. But if you hold your hand out to government reciting preferred dogma, you’ll get funding for super-computers to draw help pretty pictures which are related more to an imaginary universe created from assumptions than to the real world.
Re: Ian H
That was me. Willis also came up with about the same figures. That ballpark estimate is based on Argo missing 5% of the surface area between 60S and 60N. Here is a formula you can use to come up with your own ballpark figures
Ta = 60/P + 19.7
Ta is the average temperature of the missing area and P is the percentage of missing area. So if Argo misses 2% then the average of this 2% would have to be 49.7C to make the overall average 20.3C. With 5% its 31.7C and so on.
Perhaps you could give us your ballpark figure for how much of the oceans between 60S and 60N Argo misses? We will then know what the average temperature of this area needs to be in order for Argo to match other datasets.
Dear Willis
SST is used as a proxy for “global warming” . Given its weight of 71%, there is no global warming without increase in SST.
I’m wondering for a long time how big the impact of ocean currents can be on global average SST. Would you be able to analyse this on the basis of the Argo data?
rgds
Fascinating but I have a quibble. The Mediterranean which has no upwelling currents and thus time to develop a warm upper layer has the same temperature profile as the west coast of southern Africa, where there is a cold upwelling due to the prevailing southeasterly wind. Swimming in the Mediterranean is enjoyable and can be prolonged whereas the South Atlantic coast is usually shocking for all but the hardiest.
Hey Willis, have you checked your area averaging algorithm? If you got the weighting wrong (e.g. same weighting to 1×1 ° near the pole and near the equator) then you could have overweighted the cooler polar temperatures.
Lubos, if your theory about maximum solar heating was true, then the width of the plateau would co-incide with the area that gets overhead heating, i.e. the tropics, but looking at figure 2 you see – exactly that!
“LJ Hills says:
February 10, 2012 at 1:43 am
Fascinating but I have a quibble. The Mediterranean which has no upwelling currents and thus time to develop a warm upper layer has the same temperature profile as the west coast of southern Africa, where there is a cold upwelling due to the prevailing southeasterly wind. Swimming in the Mediterranean is enjoyable and can be prolonged whereas the South Atlantic coast is usually shocking for all but the hardiest.”
The SST in the Mediterranean varies much more strongly with the seasons than in the Benguela Current even though the annual average may be similar. In winter bathing in the Mediterranean can be very bracing:
http://magicseaweed.com/msw-surf-charts2.php?chart=83&res=750&type=sst&starttime=
> I averaged it by 1° latitude bands, and then took an area adjusted average to give a global mean
Assuming you mean that you averaged all the floats in a given latitude band together, that would be a problem, since there is clearly structure in longitude; you’ll have biased your numbers by float-count-density.
You need to average into lat-lon boxes to start with, to have any hope of getting the right answer. And you might need to do it year-to-year too, since there will be interannual variations.
“Note that there is an obvious upper limit to the ocean temperatures, the “flat-top” on the graph at just above 30°C. No matter how much incoming solar there is, the ocean doesn’t get any warmer than that. This provides a “cap” on how hot the ocean can get. Above that temperature, any extra incoming energy is converted to latent and sensible heat, rather than warming the surface.”
That’s wrong. There is no scientific basis for such a statement. Might I suggest you consider the earth is tilted and the latitude of the ocean perpendicular to the sun varies by an amount suspiciously close to the size of your plateau 😉
I wondered about it too, I know the area and wouldn’t swim around the Cape..
http://capeinfo.com/where-two-oceans-meet
http://www.capetourism.co.za/index.php?option=com_content&view=article&id=108&Itemid=155
Using pink for colder water (12°C) than green (16°C) seems a bit perverse, map on the second link.
The Cape seawater is cold so surfers wear +5mm thick wetsuits to enjoy the water. Both coastlines have very powerful currents – due caution and care must be taken. The sea in False Bay in summer often reaches 22 °C (72 °F) due to the strong south easter wind blowing the warm Agulhas into False Bay. Whereas on the Atlantic beaches the same wind pulls the warm surface water away from the coast, and this is replaced by very cold water from great depths, usually 6 – 14 °C (45 – 57 °F – light pink area), also known as “upwelled” water, which is rich in nutrients and usually clear and blue.
Why a maximum temperature? I suspect that if one would write out the simultaneous set of kinetic equations (heat in from the sun, heat out by evaporation, conduction, convection, conversion to latent heat, etc.) there would be an asymptotic steady state equilibrium temperature that is somewhat insensitive to fluctuations of the inputs/outputs. And that temp is (empirically) 19.7C. If the AGW world thought more in terms of first, second, third order kinetics and gave up on the erroneous linear projections (zeroeth order kinetics), they’d be better at predicting reality.
Here’s another of those random thoughts i get now and again.
Would a ‘land based’ set of Argo floats give a sensible reading of temperature? In the same way that the ocean is a great big integrator/averager of temperature, so would be the land. (I got that from the current excitement here in the UK for so-called Ground Source Heat Pumps (GSHP) as a ‘green’ and eco-friendly way to heat your house.) They are supposedly much better than Air Source Heat Pumps because the temperature just a few feet underground, anywhere in the world, tends to ‘pretty constant’. It certainly is clear how 3ft of dirt would average out the surface temperature and hopefully provide a true average of what went on on the surface. Day/night variations and even weekly/monthly changes would be pretty well smeared out.
But, burying thermometers is not especially a good idea, not least the practicality of reading them.
So its a pretty duff idea.
But but but, howzabout taking a leaf again from the GSHP idea and using a loop of pipe buried in the ground at 3,4 or 5 feet below the surface and circulating water through it.
Still not good, even more work than just burying the thermometer.
But but but, almost every house, home dwelling, shop and factory in the world that has a supply of tapwater, is connected to a pipe, containing water, at exactly those sort of depths. Simply turn on the tap, let it run a few moments then measure its temp. We could have millions of underground Argo floats reporting data with days from all around the world wherever anyone is connected to a public water supply. Plus, they probably only need to do one reading aper week (at most) to return a perfectly averaged measurement of the local temperature – what is the ‘Time Constant’ of dirt? Once a month might suffice. Time of day, sunny, windy,rainy, jet engines, air cons would be all pretty well irrelevant, in the same way as it is for the Argos.
What do reckon?
PS Local conditions here yesterday were..
Hi= 1.9C at 20:35 GMT
Lo- -.0.8C at 01:09
Slight freezing rain in the morning.Foggy otherwise.
Temp of cold water tap =+5.0C at GMT when I could be bothered.
PPS I cannot be the first to think about this – what’s the catch?