From the University of California – San Diego Scripps Institute, you gotta love the subheading in this PR. I didn’t know robots could travel back in time. Gosh, I learn something new every day. Apparently 300 soundings done by the HMS Challenger between 1872-1876 are enough to establish a “new global baseline” for the last century. The temperature rise is pretty much what we’d expect from LIA recovery. Though, for an outfit that hauls Titanic Chicken of the Sea debate ducker James Cameron to the bottom of the deepest ocean trench, I’d take this PR with a grain of sea salt, especially since it provides no supporting graphics or documentation. I’d sure like to see how the distribution of those 300 sounding looks. – Anthony
New comparison of ocean temperatures reveals rise over the last century
Ocean robots used in Scripps-led study that traces ocean warming to late 19th century
A new study contrasting ocean temperature readings of the 1870s with temperatures of the modern seas reveals an upward trend of global ocean warming spanning at least 100 years.
The research led by Scripps Institution of Oceanography at UC San Diego physical oceanographer Dean Roemmich shows a .33-degree Celsius (.59-degree Fahrenheit) average increase in the upper portions of the ocean to 700 meters (2,300 feet) depth. The increase was largest at the ocean surface, .59-degree Celsius (1.1-degree Fahrenheit), decreasing to .12-degree Celsius (.22-degree Fahrenheit) at 900 meters (2,950 feet) depth.
The report is the first global comparison of temperature between the historic voyage of HMS Challenger (1872-1876) and modern data obtained by ocean-probing robots now continuously reporting temperatures via the global Argo program. Scientists have previously determined that nearly 90 percent of the excess heat added to Earth’s climate system since the 1960s has been stored in the oceans. The new study, published in the April 1 advance online edition of Nature Climate Change and coauthored by John Gould of the United Kingdom-based National Oceanography Centre and John Gilson of Scripps Oceanography, pushes the ocean warming trend back much earlier.
“The significance of the study is not only that we see a temperature difference that indicates warming on a global scale, but that the magnitude of the temperature change since the 1870s is twice that observed over the past 50 years,” said Roemmich, co-chairman of the International Argo Steering Team. “This implies that the time scale for the warming of the ocean is not just the last 50 years but at least the last 100 years.”
Although the Challenger data set covers only some 300 temperature soundings (measurements from the sea surface down to the deep ocean) around the world, the information sets a baseline for temperature change in the world’s oceans, which are now sampled continuously through Argo’s unprecedented global coverage. Nearly 3,500 free-drifting profiling Argo floats each collect a temperature profile every 10 days.
Roemmich believes the new findings, a piece of a larger puzzle of understanding the earth’s climate, help scientists to understand the longer record of sea-level rise, because the expansion of seawater due to warming is a significant contributor to rising sea level. Moreover, the 100-year timescale of ocean warming implies that the Earth’s climate system as a whole has been gaining heat for at least that long.
Launched in 2000, the Argo program collects more than 100,000 temperature-salinity profiles per year across the world’s oceans. To date, more than 1,000 research papers have been published using Argo’s data set.
The Nature Climate Change study was supported by U.S. Argo through NOAA.
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Actually, there is a way to make this data useful.
Pick a time frame…..150 years, 160 years….etc.
Exactly, on the anniversary, of when the original data was taken, take another reading using the same instrumentation etc. Then use a calibrated XBT to see what the bias is.
Use the same XBT and thermometer for each location.
That way you will cut the error bars per location, and be able to calibrate the temp differential.
The results would be very interesting to read and digest.
Willis Eschenbach says:
April 2, 2012 at 5:13 pm
=====================================================
About 10 years or so ago I copied a text file of the record highs and lows for each day from 1900 on for my area from the national weather service. I copied them into an Excel spreadsheet and sorted by year. I don’t remember the exact numbers but over 60% of the record highs were before 1950 and about the same percentage of record lows were after 1950.
Now, I realize that my “analysis” of those 700+ numbers alone doesn’t say much about global temperatures over the last 100 years. Why do some give such weight to HMS Challenger’s 300 numbers? At least mine were from the same location.
Don, you’re either very funny or rather myopic. Most of us believe that the global temperature of the Earth has gone through a long series of increases and decreases. The periods of decreased global temperature often result in ice ages. One of these was the Little Ice Age. At the conclusion of the Little Ice Age, global temperatures began to once again increase, consistent with the long-term temperature cycle of the Earth. I would think that it’s a fairly self-evident statement to say that at the conclusion of a global cold period, global temperatures would be expected to increase (just as at the conclusion of a global warm period, the current time, we can expect global temperatures to decrease).
None of that has anything whatever to do with some arbitrary equilibrium temperature, which I suppose you threw in there for your own purposes. Would you care to explain those purposes?
A bit off topic, but it seems to me that during the 18th and 19th centuries, the RN was a major scientific research organization as well as a military force. Was this true of other navies of the time, as well?
Love me some data!!! Lunatics getting worked up over things that mean absolutely nothing.
Sure more data is good….. assuming people know how to properly apply, interpret, and relay the information. If this nuanced climatology has taught us anything, it’s taught us that the assumption, more often than not, isn’t valid.
Worse, because we’ve been shown exactly how invalid this madness is, even if there were to be some valid knowledge to be express, there is no trust. None…. nade….. zippo…… zilch.
Sure, I play the game like the rest of us, but, we all know this is just a game. Look at Curry’s post about SST’s…… it’s crap. It has all been crap. It’s so far down the crap line you can’t plunge it back up! Have some one tell me what the temps were in 1910. It is a lie and they are liars. Not just a lier,but a #$@ur momisugly#@ur momisugly#@ur momisugly# lier. Next we need to throw in an algorithm which creates dynamic and ever changing historical record. This is important, because we can then base our decisions on some vapid information, which we absolutely know will change. Which, isn’t that bad…. at least it is continuous, as opposed to the one that gives us updated versions when the data sets move beyond what they deem as acceptable. And, they’ll base that on some imaginary temps just like the dynamic temp data set.
Data is good? No it isn’t. Not until we rid ourselves of the #%^@ur momisugly#%@ur momisugly#$% liars. Until then that’s just information to be manipulated to tell a story one way or the other.
Error bars or not, how does one generate more digits of precision in the output than one has in the input? Even if it were physically possible to determine temperature (ca 1870) to 0.1 degree (which seems doubtful) the “data sets” are routinely published to 0.001 degree! Pure rubbish! The entire discussion above has no scientific value! I think significant digits are taught at about the seventh grade level!
Further problems …
Why didn’t they use the modern reversing thermometer, you ask? It wasn’t invented until 1874. Because of the importance of the Expedition, they were shipped out to meet the expedition. They were first used on 28 February 1875 … two years plus into the expedition.
The new thermometer is the Negretti and Zambra thermometer, 1874 model. It is shown in 1874 here.
Note that even then, it is missing two very important components shown in the next thermometer down on the page, which were added in 1878, viz:
So we likely don’t even have a consistent record throughout, unless they kept using the Miller-Casella thermometers. That would be some interesting data.
But more likely, after a few comparisons they switched to the better, simpler, more accurate gear. So what we have is a two-year record from a non-pressure compensated min-max thermometer. And we also have a one-year plus record from a non-pressure compensated reversing thermometer that doesn’t break the mercury column …
A correction to my earlier post—I thought they had not crossed their own trail, but the did do that more than once. See here for an animation of the ship’s trail.
w.
What was the temperature of the air at the surface (.01-6.0 Ft.+/-), the wind speed and the humidity reading at each location of the 300 readings? What was the method of “taking” the temp. and what was the delay between the time the device was brought to the surface and the “reading”? What was the exact location and how was the depth of the device controlled (currents? waves?) and determined? Didn’t we all just discuss the potential for errors within the “modern” ARGO system? And now “we” are comparing IT to an even less accurate method/system???
What impresses me the most is the perseverance and courage of the scientists on board Challenger. That was no luxury cruise they went on. Any data they brought back should be greatly appreciated by us today.
Dave Dodd says:
April 2, 2012 at 6:42 pm
“Error bars or not, how does one generate more digits of precision in the output than one has in the input? Even if it were physically possible to determine temperature (ca 1870) to 0.1 degree (which seems doubtful) the “data sets” are routinely published to 0.001 degree! Pure rubbish! The entire discussion above has no scientific value! I think significant digits are taught at about the seventh grade level!”
You can improve your precision given that you have a large number of measurements, but it’s difficult.
http://www.mso.anu.edu.au/pfrancis/ObsTech/Stats2.pdf
Hansen and Schmidt have thrown out three quarters of the thermometers in the 90ies saying “We simply had more data then we needed”.
No scientist would say that. Ever.
Don says:
April 2, 2012 at 5:30 pm
”
“The temperature rise is pretty much what we’d expect from LIA recovery”
What a truly remarkable sentence. What is “LIA recovery”?”
The warming that was to be expected after the end of Maunder and Dalton minimum.
” Who is the “we” who expects this recovery? Do you really believe that there is some equilibrium climate state to which the climate “recovers” after a perturbation? If so, what physical mechanisms determine what this equilibrium temperature is?”
Depends on what you define as the “normal” state of the sun.
” What, indeed, is it? Are we there yet?”
We were at the maximum and are on the way down.
” If not, when will we get there? How will you know when we get there?”
2007 Polar sea ice minimum.
“What is the rise that you would expect from this so-called “LIA recovery”?”
It’s already over.
And again from my previous query: If the 1874 device can only be read to (at best) 1 degree of accuracy, how can the following be valid? The error bar is +/- 1 degree (NOT +/- 0.0x degree) as their results indicate, or am I missing something? I was taught, integer value in MUST be rounded to integer value out (even if converting C to F) despite the 6 or 12 digits after the decimal your calculator might show.
“The research led by Scripps Institution of Oceanography at UC San Diego physical oceanographer Dean Roemmich shows a .33-degree Celsius (.59-degree Fahrenheit) average increase in the upper portions of the ocean to 700 meters (2,300 feet) depth. The increase was largest at the ocean surface, .59-degree Celsius (1.1-degree Fahrenheit), decreasing to .12-degree Celsius (.22-degree Fahrenheit) at 900 meters (2,950 feet) depth.”
I agree with Steven Mosher (12.14 pm)that publication of these old data is a very good thing. Perhaps the conclusions drawn are not as valid as the author’s claim but that is their interpretation of the data. Of course, others may have a different interpretation. This next comment on Steven Mosher’s post of 12.11 pm is picky. He states “data is a good thing”. As data is the plural a more correct phrase is ” Data are good things”
DirkH says:
April 2, 2012 at 8:16 pm
OK Read and understood your pdf link and agree with it. 300 random data points hardly seem to fill the bill of “a large number ” of measurements, no matter how they’re weighed.. I’m an old slide-rule guy–we had to WORK for our decimal points! I stand pat that the knowledge and reasoning imparted by my old Physics teacher in HS, is probably more useful that a single tree 🙂 Regards…
Lol kind of funny if you question data from 200 years ago from being inaccurate why dont you have any problems with current data collections installed on footpaths and near exhaust vents.
To be really meaningful this data would have to be adjusted for all the errors that you’ve mentioned. Perhaps our good friends at CRU could do it for us. (tee hee).
Steve Mosher:
There is a pretty consistent relationship between the change in temps over land and those in the ocean. That’s just physics.
The consistent relationship is that the ocean temps lead the air temps by several months. Just the data tells us that.
Getting the physics donkey to stop pushing the AGW cart is another issue.
Now that “This Paper” has “found a baseline”. Mark my words. The next “paper” will have us believe they have “found” the missing ocean “heat”.
There’s surely no need for any analysis of this data until Hansen has ‘adjusted’ it to show negligible warming until 1950.
Apparently 300 soundings done by
theHMS ChallengerThe would be appropriate before USS but not before HMS, unless you are refering to something pertaining to the ship e.g. the HMS Challenger expedition.
I would be interest to see a matching of Argo data with the Challanger data ie taken from an ARGO bouy closest to the position of a Challenger reading and at the same time of the year then comparing comparitive depth data. I dont know what methodology was used in the study, but there are ocean temp. readings in plenty from Cooks Voyages onwards available in ships journals mainly surface temps. but again it would be interesting to repeat the same sampling using the same equipment used in the original recordings along with modern equipment in the same locations, the results would be usefull.
So how did they prevent the thermometer warming up as it rose through the warmer temperatures?
From a purely historical perspective, I think this is a good thing. I would love to see a study of this data as it compares to any adjacent land temps (if possible). Like Steve Mosher eluded to, anything is better than nothing. I love to read old farmer diaries that give a glimpse into past weather events. The same goes for old ship records. Whether these old bouy records are precise is another thing entirely.
The best source on the scientific results of the voyage of HMS Challenger is the pdf of the original report at the internet archive:
“The instrument used for almost all the observations made on board the Challenger,
was Six’s thermometer with a double bulb, of the pattern made by Mr. Casella for deep-sea work, and generally known as the Miller- Casella thermometer.”
“During the course of the voyage, it became evident that the thermometers
as supplied were wanting both in delicacy and in accuracy.
It is true that the great source of error had been removed by the application of the
secondary bulb, so that the indications were practically unaffected by pressure, but when
it had been found that the great bulk of the ocean water is at a low and nearly uniform
temperature at great depths, it became of importance to be able to distinguish accurately
fractions of a degree. With the thermometers supplied this was impossible, because
they were so short for the range of temperature they had to show, that the length
occupied by one degree could not easily have been subdivided beyond a quarter, even if
the scale had been engraved on the stem, and it was impossible to attain even that degree
of accuracy with certainty when the scale was on a slip of glass at the side of the stem, and about a quarter of an inch away from the index, the position of which had to be determined
in reference to it. In order to remedy this defect, Professor Wyville Thomson
ordered two thermometers to be sent out specially constructed to show low temperatures
with accuracy.
“During the course of the voyage Messrs. Negretti & Zambra patented an instrument
which promised to fulfil the conditions required of a thermometer for isolated observations.
Staff-Commander Tizard made an extensive series of experiments with it under various
conditions…
“It was found in practice that the propeller being arrested, after it had turned over the thermometer, brought such a strain on the cogwheel W as to twist it off the spindle and cause its loss. This defect was remedied by Mr. Ferguson, the Chief Engineer of the Challenger, who
applied an ingenious apparatus…Several thermometers for use in the apparatus were forwarded from time to time. A great number were found broken when they reached the ship, owing either to imperfect packing or negligence in the transport, but a sufficient number arrived in safety to admit of their having a fair trial.
“The first time they were used was in the Sulu Sea, where the minimum temperature is
reached at a depth of 400 fathoms, and it was thought a good opportunity to try whether
the water at greater depths exceeded this temperature.”
The report includes charts of temp readings as well as comparing the Miller-Casella with the Negretti and Zambra with locations, dates, depths and readings.
http://ia700404.us.archive.org/1/items/p1reportonscient01chaluoft/p1reportonscient01chaluoft_bw.pdf
It’s too bad that this data is being used in a quantitative comparison to ARGO measurements. If it had simply been presented as a qualitative assessment of the Challenger data, with the conclusion that 300 measurements taken with 19th century equipment inferred a deep ocean temperature consistent with modern instruments, it would have been interesting. As a baseline to establish a century long trend is complete nonsense.
If Challenger really did produce a credible, accurate measurement of the global ocean heat content using only ropes, weights and thermometers, can we get our money back for all those wildly complex and expensive Argo floats?