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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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.
Why was it to be expected? Why didn’t it keep getting colder? Why didn’t it stay as cold as it was?
” 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.
That doesn’t answer any of the questions.
” What, indeed, is it? Are we there yet?”
We were at the maximum and are on the way down.
What determined this maximum? Why would we be “on the way down”? When will this decline that you believe has begun stop? Why won’t it stay warm? Why won’t it get warmer still? What are the physical mechanisms that determine this?
” If not, when will we get there? How will you know when we get there?”
2007 Polar sea ice minimum.
And did you predict that in advance or are you just conveniently picking a single piece of data that you think might support your belief?
“What is the rise that you would expect from this so-called “LIA recovery”?”
It’s already over.
You’ve failed to offer any substantive physically meaningful justification for that claim.
Camburn says:
April 2, 2012 at 5:56 pm
Expendable bathythermographs are not very accurate; good enough for government work (ships/submarines) but not accurate enough for scientific work. They are probably less accurate at determining their depth than a calculated ‘thermometric depth’ using 2 thermometers.
(Citations available if required)
P. Solar says:
April 2, 2012 at 2:11 pm
http://judithcurry.com/2012/03/15/on-the-adjustments-to-the-hadsst3-data-set-2/
Note that all of Australia’s high temperature records were set in the 1940s, during the WWII drought:
Question – does anyone know how many of those American warships which returned the anomalous temperature readings during the war years were based in the western Pacific?
“…As in the Federation drought, dry conditions were more or less endemic during the period 1937 through 1945 over eastern Australia….”
Christy et al reprted in Jan 2001 (I believe it was Geophysical Research Letters) that ocean water Temperatures, and Ocean air Temperatures (near surface for both) are NOT the same, nor are they correlated. So ocean lower troposphere Temperatures cannot be recovered from early ocean water temperature based data going back 150 years or more. Well that’s only 70+ % of the earth surface missing from the historical records; well not counting the land areas, that aren’t sampled either.
So 300 new samples are going to be a big help ? Well I think not.
P. Solar says:
April 2, 2012 at 2:11 pm
Another interesting article at Judith Curry’s site on HadSST and magic bucket syndrome.
http://judithcurry.com/2012/03/15/on-the-adjustments-to-the-hadsst3-data-set-2/
see fig 1a and fig 1b
Note that all of Australia’s high temperature records were set in the 1940s, during the WWII drought:
Question – does anyone know how many of those American warships which returned the anomalous temperature readings during the war years were based in the western Pacific?
“…As in the Federation drought, dry conditions were more or less endemic during the period 1937 through 1945 over eastern Australia….”
“”””” Steve Mosher:
There is a pretty consistent relationship between the change in temps over land and those in the ocean. That’s just physics. “””””
Well ocean currents are at most a few knots, while ocean wind speeds can differ from that by orders of magnitude.
So why now does Physics tell us how the land responds to ocean or verse vicea ? I don’t see why air Temperatures over land in air that was earlier over some piece of ocean thousands of miles away, would in any way reflect heat stored in the ocean.
“”””” Ian of Fremantle says:
April 2, 2012 at 8:55 pm
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” “””””
A more pertinent question is :- When is data really data, and not simply noise.
What experimenters record is “samples”. Those samples are NOT data, unless all the rules of sampled data systems are complied with; mostly the Nyquist sampling theorem. And even the average of such samples is unreliable, for just small deviations from the Nyquist criterion; just a factor of two undersampling will do it.
@ur momisugly Don,
You obviously need to bone up on the basics of climate a LOT more so you can ask meaningful questions. You complain about not getting meaningful ANSWERS, but that has a lot to do with your questions not being meaningful in the first place.
One immensely key thing about climate that you seem to miss is that although it is a pretty darn chaotic system, it tends to be very cyclical in nature and we do have at least some understanding of the duration and sign of some of the cycles. Some cycles induce a positive sign to the “temperature anomaly” whereas other cycles induce a negative sign to the “temperature anomaly”. If there wasn’t a number we could at least CONSIDER as being “NORMAL” then calculating anomalies would be meaningless.
At any rate, the Roman Optimum, (also known as the Roman MAXIMUM) was darn warm, maybe even warmer than the “Medieval Warm Period (Medieval Maximum)”. The Dalton and Maunder MINIMUMS were pretty darn cold.
So my recommendation would be that first you do enough research to realize that there is plenty of evidence that climate is cyclical in nature and that when it gets too warm or too cold it has a tendency to return to a midpoint of the cycle after the perturbations. That cyclical midpoint is not necessarily the same temperature that it was a Billion years ago, but for the entire time that intelligent man has been on the planet, it HAS been about the same temperature, with cyclical up and down fluctuations, some more significant than others (and several that have been more significant than our current “warming”.
Once you have done enough research to convince yourself of the cyclical nature of the climate system, then you can probably begin to ask meaningful questions.
“Why isn’t the earth a constant ball of ice?” and “Why doesn’t the earth heat up uncontrollably and become like Venus?” are interesting questions, to be sure, but they have been answered adequately by a few hundred years of physics research already and you need to have that basis in order to ask questions which will elicit answers which you will find “meaningful”.
“Possible 19th Century La Nina events have been identified in: 1872-74, 1875-76,”
http://sites.google.com/site/medievalwarmperiod/Home/historic-el-nino-events