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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AncientOfDays says:
February 9, 2012 at 4:49 pm
Right. You think I quoted it, but I didn’t know it was from “Ulysses” by Tennyson. I memorized it in high school, my friend, I’ve known it’s by the guy with the comma in his name for fifty years.
You get a full point for recognizing the poem, but you lose a point for making foolish assumptions.
w.
@Doug Proctor at 4:48 pm:
Your 2)b) point is not correctly stated, Doug. The “fuzz” is not “error/accuracy limits”. It is real data. There is nothing erroneous about it. Yes, they are somewhat “outliers”, but they really only represent what the continental coastlines are doing to the currents.
StuartMcL says:
February 9, 2012 at 7:49 pm
“Mark James says:
Aren’t we getting a little worked up here over 1/2 – 3/4 of one degree?
—————————————————————————————
But isn’t that the about the same size as the whole warming over the 20th Century that everyone is so worried about?”
Yes Stuart, those numbers are in line with what the earth has actually experienced on average over the 20th century, but it is far from what the warmists promise us is actually happening or is about to happen, which is why I don’t think it makes a dent in their wild assertions and lies. It’s just not enough of a difference.
Ian H says:
February 9, 2012 at 4:54 pm
That could be it, Ian. My problem is, my bad number detector says there likely isn’t enough shallow areas to do it. Lemme think about it. If I look at Figure 1, I’d say the white areas by the coasts are less than 10% of the total ocean area for sure. Lets call it 5%.
The ARGO data is maybe half or more of a degree cooler than the others. So if that is to be compensated for by 5% of the surface, that 5% would have to be ten degrees C (18°F) warmer at all locations than the surrounding ocean …
Nope. Not happening, and even half of that is not happening. As a seaman I can tell you that there is nowhere near that kind of surface temperature rise just because the ocean bottom has shoaled from a kilometre deep to half a kilometre deep. You do get a slight warming in very shallow water (less than ten metres or so) right alongshore, but it rarely extends further seawards than the five fathom (10 m) depth line, and usually not even that deep.
So no, the idea is good, but the proportions are wrong.
Thanks, interesting thought,
w.
Best Thread Title … Ever.
Besides the “fuzz” as Doug at 4:48pm calls it, my attention is drawn to the DOWNward block of data in the SH between 0° and 30°. It is a clear demarcation at the Equator between NH and SH.
I’ve spent time in Peru, at high and low elevations, and I KNOW that this coolness does exist, well within the tropics and within the SH Hadley cell. I looked at that as being from the Humboldt Current, but that looks like more data points than just off the Peruvian/Ecuadorian coast would produce.
Anybody got any ideas what that downward bulge is all about?
little polyp says:
February 9, 2012 at 5:03 pm
Yes, it is the method that I used to calculate the average. It’s called area-averaging. It uses the cosine of the mid-latitude of each latitude band to adjust (weight) the average of each latitude band so that it is adjusted for the fact that different latitude bands have different areas.
w.
Anthony, I like your approach to this.
IMHO, the first thing one should do with any dataset is to plot it ALL out, to see if there are any obvious errors in what you are doing – but also to have a basis/foundation from which to view the subsets – NH/SH, summer/winter, etc.
Willis –
Hey, Duded, I like that using the cosine thing. It makes perfect sense.
Steve Garcia
Also, Willis, I mistakenly put in Anthony in the post at 9:17pm.
It should have been addressed to you.
Crazy Brave Robert of Ottawa
and if the Noah’s Arks and the Salty’s don’t get you then the sea wasps might and make sure you don’t step on a stone fish – that is a really painful way to die. ( It is no accident that I live in Tasmania )
Philip Bradley says:
February 9, 2012 at 5:45 pm
Exactly. At that point, increased forcing merely makes the waterwheel spin faster, moving more water aloft and back down again, and pumping more energy to the poles to be rejected to space.
w.
Mike says:
February 9, 2012 at 6:27 pm
I just report them. That’s what Argo said.
w.
@Doug Cotton at 8:38 pm:
Good observation, Doug.
Willis –
Doug Cotton makes a good, reasonable point at 8:38. Have you the capacity to look at the satellite data for 60N-60S and only the oceans?
Steve Garcia
Mark James says:
February 9, 2012 at 7:06 pm
Bear in mind that Hansen claims we can measure not just the surface but the top mile of the ocean to 0.004°C per year … I’m just trying to understand what the real numbers and the real errors are like here. I’m not “worked up”, I find it interesting.
w.
I am not sure you meant anomaly in that sense, as Fig1 deals in absolutes, but with the La Nina pattern still there causing westward movement of warm shallow water past the Indonesian flow through, there is still plenty of 30plus water there.
http://www.bom.gov.au/products/IDY00007.shtml
richard verney says:
February 9, 2012 at 7:38 pm
Hey, before taking a stand, take a look. At Figure 2. Yes, there are occasional 34 degree readings. But obviously, they are not common at all.
The existence of a maximum ocean temperature has been known for some years. It is not hard and fast, obviously. But look at Figure 2, Richard. That’s real data. How often does it go above about 31°C?
Hang on … OK, here’s the numbers. There are 696,872 Argo surface temperature measurements in the dataset. By one degree interval above 28°C we have the following numbers of measurements:
28° – 29°: 62618
29° – 30°: 48374
30* – 31°: 9033
31* – 32°: 567
32* – 33°: 103
33° – 34°: 24
w.
Greg Cavanagh says:
February 9, 2012 at 7:55 pm
Here’s my description of what I did, from the head post:
w.
What are you doing Willis? This is a comparison of the temperature of shallow water to nearby deep ocean. What has that got to do with anything. I never claimed that shallowness made water warm. Please don’t bring out the straw man.
Your claim is irrelevant because the geographic distribution of unsampled shallow areas is very uneven. Look at it. The bulk of the unsampled area is in the tropics. There is a huge area around Malaysia – Indonesia – North Australia. Read the comments. You’ve got divers talking of diving in 30C water in Darwin, and mariners commenting on commonly seeing high water temperatures in that region – up to 34C. There is another big white area in the Carribean. Do you reckon the water might be warm there too? Quite likely.
Someone earlier (sorry I’ve have to scan back to see who) did a ballpark estimate that the temperature of the unsampled bits would need to be around 30C to make up for the difference. For the part of the world we are talking about that temperature is high for sure, but it was only a ballpark estimate and this isn’t out of the ballpark.
Hansen’t number may be “precise”, but by comparing it with the other datasets, it doesn’t appear to be “accurate”. There can be quite a difference, of course.
It makes my head ache thinking what it would take to apply geostatistics to this set of data, but quite often a headache resolves into a procedure–.
One of the biggest bugaboos in comparing results from different datasets from the same “urn” is that seldom is the “sample support” equivalent. To normalize them for comparitive purposes can take horendous effort, if it can be done at all. Pierre Gy is one of the experts in the field of sampling theory, sampling practice, heterogeneity, sampling correctness, and statistical process control. Indeed, he has a book out with approximately that title.
steven mosher says:
February 9, 2012 at 8:06 pm
Indeed it is an interesting question.
The spatial coherence is greatly underestimated by the color scheme, which groups together the data in 3° bands. The ocean is far from spatially coherent.
I have a huge advantage in this discussion in that I’ve fished commercially for albacore. The albacore are very sensitive to the temperature. So when you fish albacore, you drive around the ocean day after day, watching the thermometer and trying to find the water of the right temperature. So I’m very familiar with the vagaries of ocean temperatures.
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.
Anyhow, that’s what I’m looking at is the actual data.
Thanks,
w.
Blade says:
February 9, 2012 at 9:14 pm
Thanks, glad someone liked it.
w.
AncientOfDays says: “Not Jason, but “Ulysses” by Tennyson. Both Greeks though. You get 1/2 a point.”
So was Aristotle Onassis. Zero points.
Willis, the flat part of the graph in the tropics is an illustration and support of a paper going back to 1979 on why the T is limited in the tropics, and is furthermore indicative of how the percentage of increasing energy going into evaporation, latent heat, and convection increases, verses the energy going into T.
This is also supportive of additional LWIR in the tropics mostly going into increeeased evaporation and convection, what with LWIR being absorbe at the surface. Whereas a much larger percentage of increase in solar induced SWR would penetrate far below the surface and have a far longer residence time.
Your comment about the cooler SH was likewise curious indeeed. The SH recieves 7% more insolation in it’s summer, yet apparently that absorbed heat is transfeered north?