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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Willis – “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 … ”
Let’s accept your figures for a moment. The 5% doesn’t have to be 10C warmer than the immediately surrounding ocean, it has to be 10C warmer than the global average for it to have the effect on the global average that would resolve the discrepancy.
If you look at the areas which are shallow – mainly around Indonesia and the Caribbean – then these areas are near where the temperatures are above 27C (the red colour on your colour bar). So that’s pretty close to your ballpark estimate of 10C warmer than the global average.
A way to resolve this would be to subsample the HadISST/Reynolds data by leaving out the data for Indonesia and other shallow sea areas and see how that affects the global average they produce. Also, of course, directly plotting the spatial differences.
It could be that there’s a measurement bias in terms of what the Argo floats define as being the surface, bearing in mind that when they take their measurements they are drifting up from colder temperatures below, and one would assume some sort of lag would be involved while the instrumentation warms up.
Of course, some corrections were applied to remove the artifacts. Somehow I doubt that that those corrections would be the case – you would have to correlate original
John says:
February 10, 2012 at 4:39 am
“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.
=================================
John, I will look for the link but a paper was published in 1979 about this, and it has only been supported since. No, it is not absolute, but likely close for any increase in LWIR, because that energy is absorbed at the very top of the ocean. For certain the rate of evaporation to energy (T) increase is not linear, and as you approach these T, ever more of the energy does go into evaporation. I think some studies indicated three times more W/V increase then the models indicated. A higher percentage of SWR certainly does go below the surface.
“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.”
Don’t icebergs drift down to these latitudes?
This also raises another point in my mind: How, in practice, do the floats actually distribute themselves over time in the vicinity of coasts, islands, icebergs etc? Flotsam and jetsam doesn’t distribute itself uniformly, and the currents won’t help it to either. So even within a grid cell we would expect major heterogeneities. More so at land-ocean interfaces.
…and my contribution…
Post hoc, Argo propter hoc.
Interesting.
If ice-covered areas are excluded. by all sea surface methods, then does the average temperature go up if the sea-ice covers a larger area?
What, exactly, is meant by “average sea-temperature” anyway? Is it surface, at some depth x, and what counts as “sea” ? How is the average computed? If you use satellite data, does cloud cover affect the reading? Doe that mean that satellite data gives a higher average reading, since (presumably) cloud cover would lower sea temperatures? If you are measuring just surface temps, then storms would have a localized mixing effect, and skew data.
When you are trying to measure tenths of a degree, lots can go wrong.
Willis Eschenbach says: February 9, 2012 at 9:44 pm
//////////////////////////////////////////////////////////
Willis
Thank you for getting back to me. Engaging in debate is the cornerstone upon which science is properly conducted. You appear not to have understood the limited point that I made. I comment further.
1. First, my observation was limited solely to your assertion that “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..” I made no wider observations on your wider analysis. In particular, I made no comment upon whether the higher sea surface temperatures observed by me would, if properly incorporated into your analysis, have a significant effect on your assessed average temperature of 19.7degC.
2. Second, your quoted assertion either states, or at any rate implies, that the process of evaporation and convection and conduction (the latent and sensible heat therein involved) puts an upper cap on sea surface temperature AND that that cap is placed at 30degC.
3. Third, I would not disagree that there is an upper cap at which surface sea temperature can obtain. I would accept that the process set out in your assertion plays a part in that cap. However, that process is not the only process in play, and I suspect it is not the dominant process. In particular, surface temperature is kept low because of the amount of solar irradiance penetrating the oceans (angle of incident, wavelength absorption varying with depth, cloudiness etc), ocean currents distributing the warm near surface temperatures to other areas and ocean mixing whereby near surface temperature is overturned with cooler water coming from lower depths. All these processes in which I include yours (and no doubt others as well), act to put a cap on surface temperature.
4. Fourth, I merely join issue with the assertion “No matter how much incoming solar there is, the ocean doesn’t get any warmer than [30degC]…Above that temperature, any extra incoming energy is converted to latent and sensible heat, rather than warming the surface” My joining of issue with your asserted cap of 30degC was based on REAL DATA and on a lot of REAL DATA. As I observed, I have reviewed thousands of ships logs which contain many hundreds of thousands of recorded entries based upon empirical observation. This is REAL empirical data, yet you seek to infer by your comment when you refer me to figure 2 and state: “That’s real data” that the data to which I refer is not real data and implicitly should not be given the same weight.
5. Fifth, you then at the end of your response set out a summary of the ARGO data reviewed by you. This summary suggests that nearly 10,000 points/sets of data show a temperature exceeding 30degC. That alone, would indicate that even based upon the data that you yourself have reviewed your assertion of a 30degC cap for surface sea temperature cannot be correct.
6. Sixth, as other commentators have pointed out, ARGO does not sample relatively shallow waters. These shallow oceans not sampled are likely to contain a significant area where warm surface temperatures are experienced. A point that you have conceded but countered with the observation that in the overall scheme of things the area involved is not particularly significant. You might be correct on that caveat, but my point is twofold, first that it would have added to the near 10,000 data samples you set out in your summary and second, the cap on ocean temperatures is a physical process not dependent upon the number of data samples taken. It does not matter that only about 10,000 out of about 700,000 data sets show a temperature exceeding 30degC. Misquoting Einstein, I only need to show one data set that contradicts your assertion of there being a 30deg C cap to prove your assertion wrong. On your own evidence there are nearly 10,000 sets of data establishing the incorrectness of your assertion!
7. Seventh, it is clear that not only on your own evidence (the near 10,000 data sets you referred to) as well as my own personal experience based upon the examination of hundreds of thousands of ship log entries that your assertion that there is a cap of 30deg C on sea surface temperature is wrong.
8. Eighth, since you have had some involvement in commercial shipping, you may well know that commercial shipping frequently employs the services of weather routing agencies. There are many such agencies such as Oceanroutes, Marincom just to name a couple. Ships all over the world will report their position and weather data to these weather routing agencies. These weather routing agencies compile a data base of observational data from 1000s of ocean going ships. They also utilize satellite weather imaging and of course, traditional weather charts. Based upon all this data, they give routing advice to ships utilizing their services. So when I say that I have reviewed thousands of ships logs, although I did not mention it, I have additionally reviewed thousands of reports compiled by these weather routing agencies such reports making use of observational data not only from the ship in question but also from other ships in the near vicinity (the logs of which I might not have reviewed). I have also reviewed numerous charts from leading hydrographic institutions which set out details of sea surface temperature and others sea temperatures at various depths. For your information, you might like to look at http://www.wriwx.com/yacht/seaweather.php which gives an indication of the type of information given to Masters of ocean vessels from which you will note that the “BASIC PACKAGE: Includes all data available in Lite Package, plus Coastal Zone and High Seas/Offshore Forecasts, .WRI Heavy Weather Summaries, WRI Port/City ForecastsTropical Cyclone Tracker, 6 hourly Forecast Charts through 48 hours for:- Wind Direction/Speed- Sea and Swell Height/Directions/Periods- SEA SURFACE TEMPERATURES – Precipitation- Sea Level Pressure- Visibility Forecast data coverage includes North and Central America.” (my emphasis).
9. Ninth, I also have other empirical observational data upon which to base my view that 30deg C is not the upper cap of sea surface temperature. In the summer my swimming pool regularly gets up to 35 to 36 degC in mid/late July to mid August, and when there is a particularly hot summer it has reached 38 or even 39 degC. During the height of summer, there is much evaporation and yet this evaporation does not restrict the pool temperature to 30degC. This too suggests that the latent heat involved in evaporation etc does not place a cap of 30degC on surface temperature of water bodies.
10. Tenth, my comment regarding 34degC temperatures is limited solely to your assertion that there is effectively a 30degC cap on surface sea temperature due to evaporation etc. When I say that a temperature of up to 34degC is commonly observed, I am not seeking to suggest that this extends to all oceans and all seas. I am merely making the point that a temperature of around 34degC is not seen merely once in a blue moon, but rather that it will be seen regularly at various locations (albeit this may be a limited number of locations) such that it is not an outlier but is in fact a characteristic of the surface temperature of the ocean at that point.
Sorry for the length of this post. The point you raised as to what temperature the sea surface is capped at and why that is so is not of relevance to your analysis of the ARGO data but I feel obliged to explain why a remain of the firm view that your assertion in that regard is not correct. I do this mainly because, I consider that understanding the oceans is the key to understanding global warming and how the climate behaves and I am of the view that unless the oceans are significantly warming there can be no cAGW come what may.
“Ian H says:
February 9, 2012 at 4:54 pm
Argo doesn’t measure shallow areas”
That would explain the absence of data for the North Sea.
So shallow that fishing boats often snag their nets on the stumps of ancient trees, swamped by post glacial sea level rise and a tsunami which washed away what remained of the landbridge between Britain and mainland Europe.
The same nets also dredge up human manufactured artifacts such as flint tools.
I wonder if the Flood myths are a folk memory of this catastrophic rise in seal levels?
Willis, can you provide the precise URL of the data set plotted here? Thx, Steve Mc
Water vapor-pressure rises exponentially with temperature, so it certainly wouldn’t surprise me to learn that this puts an effective ceiling on ocean surface temperatures.
John says: February 10, 2012 at 4:39 am
//////////////////////////////////////////////////////////////////////////////////////////////
John
You are correct. The quoted assertion made by Willis is incorrect.
You may like to see my posts of February 9, 2012 at 7:38 pm and February 9, 2012 at 7:49 pm wherein I point out that temperatures of 34degC are commonly to be observed. There is not a cap of 30degC imposed upon surface sea temperature, I can categorically confirm that from the copious amounts of empirical observation that I have personally reviewed.
I would not disagree that by necessity there will be a cap on surface temperature that can be achieved. The mechanism suggested by Willis for a cap to surface temperature existing is in my opinion a valid mechanism but not the only mechanism at play.
I have written to Willis further expanding upon my views. This response is presently tied up in the moderating process.
Willis –
Considering how shallow Argo Buoys operate, it is quite surprising that so many white areas are shown in Figure 1. The western Gulf of Mexico – what is that all about? And did Indonesia bar them from locating them in her waters?
@tty 12:15 am:
tty, looking at Figure 1, it appears the Argo data has all those covered, except it looks like Ireland does not have any Argo buoys in the colder waters you mention.
@M.A.Vukcevic 1:20 am:
“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.”
Looking at the ocean current map at your link, I am always aggravated when ocean current maps short-circuit or completely leave out the Gulf of Mexico. That slow circulation within its basin is the source of the heat in the Gulf Stream, and yet most ocean current maps pretend that doesn’t even exist. This is espacially true of the THC maps – and I suspect that that is because the Gulf current’s heat runs counter to their argument that the N Atlantic is somehow ‘sucking’ the water north, which is a patently ridiculous idea. Suction can only happen in a closed system, else leaks drop the static pressure to zero mighty quickly. Positive pressure (such as the water coming out of the Gulf), on the other hand, can push water. That outflowing water then gets redirected by the coriolis effect and the shape of the American east coast to the north and the east. In Willis’ Figure 1, notice the red in the western Atlantic extends considerably more N than the eastern Atlantic or any other area in the Atlantic or Pacific. According to THC that is due to suction. Poppycock.
willis
“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.”
interesting question is how can you know that? think about it.
assume two measurement locations 100km apart. both at 28C. what does it mean to say there is spatial coherence?
I don’t dispute the rise in temperature is non-linear. However, I think the idea of a cap at 30oC is wrong and “any extra incoming energy is converted to latent and sensible heat, rather than warming the surface.” If the intensity of the sun increased I’d expect maximum surface temperatures to increase.
The Earth is tilted at about 23o this means during the Northern hemisphere summer the sun is most intense at around 23o north and during the Southern hemisphere summer the sun is most intense about 23o south. I’d suggest the reason for the plateau is because over this range at some point during the year it’s subject to the maximum intensity of the sun and this heats up the ocean to around 30oC. Obviously there is a lot more going on but the presence of a plateau is in my opinion much more likely to be due to the changing of the seasons.
I don’t know how to do superscript but they should be degrees and not o’s.
[Most web writers here just use either deg C, or just C – with the degrees symbol implied. Robt]
Pete in Cumbria UK says:
February 10, 2012 at 4:59 am
Excellent idea from a climatological POV. Problem is it would put Phil Jones, poor old Harry and many others out of work and it would cost a few millions to implement world wide. We obviously can’t afford to spend those millions when we need to spend trillions to save the world. An additional problem is it might not tell us what our lords and masters want to hear.
John said @ur momisugly February 10, 2012 at 10:15 am
Robt, John was wanting degrees for lat. & long, not temp. On the PC, hold down Alt and type 0176 on the numeric keypad (not the numbers on the top row). Let go the Alt key.
[Thank you. Robt]
[On a Mac it’s opt+shift+8 and on a PC it’s: *& deg ;* (with no spaces or asterisks.) WordPress doesn’t support sub- or superscripts. ~dbs]
feet2thefire says:
February 10, 2012 at 9:49 am
“tty, looking at Figure 1, it appears the Argo data has all those covered, except it looks like Ireland does not have any Argo buoys in the colder waters you mention.”
And your comment suggests that you are not very good at geography.Figure 1 clearly shows that Argo has zero coverage in the areas i mentioned.
tty –
Shallow areas around Ireland? To the south? SE? E? Those aren’t shallow, even if they are white.
To the west, it is covered. Between Ireland and Wales, there is the Isle of Man, and to the south are the Scilly Isles. The Isle of Man has palm trees, and the Scilly Isles is famous for growing tropical plants by the millions, so you can’t be talking about those areas as being colder water.
My geography is just fine, thank you.
John says:
February 10, 2012 at 10:13 am
I don’t dispute the rise in temperature is non-linear. However, I think the idea of a cap at 30oC is wrong and “any extra incoming energy is converted to latent and sensible heat, rather than warming the surface.” If the intensity of the sun increased I’d expect maximum surface temperatures to increase.
The Earth is tilted at about 23o this means during the Northern hemisphere summer the sun is most intense at around 23o north and during the Southern hemisphere summer the sun is most intense about 23o south. I’d suggest the reason for the plateau is because over this range at some point during the year it’s subject to the maximum intensity of the sun and this heats up the ocean to around 30oC. Obviously there is a lot more going on but the presence of a plateau is in my opinion much more likely to be due to the changing of the seasons.
============================================
I agree that the effect is not 100% I am somewhere between Willis and Richard Verney on this. For LWIR it may be close to 100%, as the energy is 100% absorbed in the top ocean layer. For SW solar radiation I accept that the limit is less defined as this input is absorbed over the third demension of depth. The problem with Richard’s pool is it cannot produce clouds, another limitation.
@John 10:13 am:
John, either you are missing something or I am. The Argo temps Willis has used are not summer readings – they are ALL the data, summer and winter, and, I suppose, everything in between. It has nothing to do with the tilt in summer in the NH or SH.
Also, Willis isn’t saying there is a cap, as much as he sees that the data flattens out at about 30-31C and he is noting that it is a real curiosity. It isn’t something Willis put into it; it is just in the data. Therefore it is as real as the data. WHY it is so he isn’t really speculating, because he knows this exercise is just a ‘let’s look and see what this shows” kind of thing.
At the same time, yes, it does appear that some mechanism must be occurring to limit the “All-Argo” temps at that level. Right now anything anyone says is just a guess, maybe an informed guess, but still just a guess.
Several folks have pointed out that I neglected to include the percentage of ocean area in my calculation of the average shown in Figure 2. They are correct. I have recalculated the average including the weighting by percentage of ocean in each latitudinal band. I find the corrected average to be 19.9 instead of 19.7 … I’ve noted that in the head post. It doesn’t solve the puzzle.
w.
Steve McIntyre says:
February 10, 2012 at 8:31 am
Sorry for the lack of detail. It’s 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”
To read it in once it was downloaded, 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)As you know but others might not, you’ll need to change the filepath in the final line to wherever you have put the “Argo_TS_0000.dat” file.
All the best, I’ve added this info to the head post.
w.
Re; feet2thefire
Between Ireland and Wales there is the Irish Sea. The Isle of man is North and slightly West of Wales and approximately 40 miles from Whitehaven in Cumbria. The Isles of Scilly are just off the coast of Cornwall (about 20-25miles) in the Celtic Sea.
The Isle of Man might have palm trees (I have no idea) but if they exist they are not native. The average maximum temperature for the Isle of Man, in the height of summer (July, August), is 17C. Not exactly a tropical paradise. The Isles of Scilly fair a little better with and average of 19C, but again, it isn’t exactly a tropical paradise.
David says:
February 9, 2012 at 10:35 pm
I know, as I said in the head post the knowledge of a limiting mechanism keeping SSTs below about 30-31°C is not new. People think I make this stuff up. Here’s just one study of the phenomenon, emphasis mine
w.
John, Windoze?
° copy and paste from character map.
Or numeric keyboard Alt+0176
°
http://wattsupwiththat.com/test-2/