There has been a lot of discussion lately about the accuracy of measuring Sea Surface Temperatures prompted by a new study from Phil Jones from the University of East Anglia and Director of UEA’s Climatic Research Unit. The measurement issue for sea surface temperatures that Dr. Jones is studying was recently showcased in an article in the UK Independent.
I’m going to present the article here first, and then we’ll talk about how sea surface temperatures have been measured, and what sorts of issues the changes between cloth buckets, metal buckets, and engine inlets actually entails.
At first glance, I see this issue raised by Phil Jones as not being well thought through, and ignoring the measurement environment actuality, instead focusing on the change in bucket types as being “absolute”. I think it has a lot of grey area, and a lot of potential errors that haven’t been considered. I’ll cover those in the next part, but for now please read the article and let me know what you think.
Case against climate change discredited by study
By Steve Connor, Science Editor
Thursday, 29 May 2008
A difference in the way British and American ships measured the temperature of the ocean during the 1940s may explain why the world appeared to undergo a period of sudden cooling immediately after the Second World War.
Scientists believe they can now explain an anomaly in the global temperature record for the twentieth century, which has been used by climate change skeptics to undermine the link between rising temperatures and increases in atmospheric carbon dioxide.
The record for sea-surface temperatures shows a sudden fall after 1945, which appeared to go against the general trend for rising global average temperatures during the past century.
Skeptics have argued it supports the idea that rising temperatures have more to do with increased solar activity – sunspots – than increasing levels of man-made carbon dioxide exacerbating the greenhouse effect.
However, an international team of scientists has investigated the raw data from the period. They found a sudden increase from 1945 onwards in the proportion of global measurements taken by British ships relative to American ships.
The scientists point out that the British measurements were taken by throwing canvas buckets over the side and hauling water up to the deck for temperatures to be measured by immersing a thermometer for several minutes, which would result in a slightly cooler record because of evaporation from the bucket.
The preferred American method was to take the temperature of the water sucked in by intake pipes to cool the ships’ engines. Those records would be slightly warmer than the actual temperature of the sea because of the heat from the ship, the scientists said.
Taking into account the difference in the way of measuring sea-surface temperatures, and the sudden increase in the proportion of British ships taking the measurements after the war, the result was an artificial lowering of the global average temperature by about 0.2C, said Professor Phil Jones of the University of East Anglia in Norwich.
“It occurred in the period of the 1940s when the number of observations of sea-surface temperature were markedly fewer than either before or after that period and most of the measurements were made by British and American ships. This made the apparent anomaly more pronounced,” Professor Jones said.
The study, published in the journal Nature, found that the global average temperatures in the late 1940s stayed roughly the same rather than falling. David Thompson of Colorado State University, the team’s leader, said a drop was, in effect, an artifact rather than a real observation.
“I was surprised to see the drop so clearly in the filtered data, and working in partnership with others, realized it couldn’t be natural,” Dr Thompson said.
Although the initial drop was significant, it did not last. By the 1960s, many other nations began taking ship-borne measurements of ocean temperature, minimizing the discrepancy.
Professor Jones said that the study lends support to the idea that a period of global cooling occurred later during the mid-twentieth century as a result of sulphate aerosols being released during the 1950s with the rise of industrial output. These sulphates tended to cut sunlight, counteracting global warming caused by rising carbon dioxide.
“This finding supports the sulphates argument, because it was bit hard to explain how they could cause the period of cooling from 1945, when industrial production was still relatively low,” Professor Jones said.
A similar problem could be occurring now with the move from ship-borne measurements to those from unmanned buoys, which tend to produce slightly lower records. This could explain why global average temperatures in recent years have leveled off.
FYI: According to the American Meteorological Society:
bucket thermometer—A water-temperature thermometer provided with an insulated container around the bulb.
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Phillip_B:
Thanks for answering. So, I’m not reading that wrong. They are actually taking water temps and using it as a proxie for air temp.
That being said, did they measure water temp. exactly 5 ft. below the water at the same location over many years? Seems to me if air temp. was taken then “proxied back, (if that’s a phrase), that would have better attributes then water temp. At least then one could time, date, location, etc. stamp the measurement and adjust accordingly. If one were trying to measure the ocean heat content, measuring water temps would make sense to me. But you can get such rapid changes in air temp. and for intent and purpose zero change in water temp. over the relatively short term, to use water temp. as a proxie to air temp. just sounds “fishy” to me.
Again, thanks for answering.
I don’t think there is any way that ships could have surveyed water temperatures over a large enough extent of the oceans over the years to have a viable plot of water temperature vs. time. I wonder if they are examining the calibration data for those devices that made the readings?
Evidently, climate change means not only changes in the future, but changes in the past.
Eppure, si rinfresca
The key point in all this is that the “scientists” made a wild-assed guess without any factual support in adjusting the data. They just made it up! Why in the world would anyone put any credence in the work of such people? If this is what passes for real science, all scientists are in for a serious collision with reality. Voters won’t pay for this kind of garbage forever. If making up wild-ass guesses isn’t standard procedure for scientists, then the real scientists better start actively getting in front of exposing the frauds. Otherwise, they are going to get tarred with the same brush when the backlash comes.
Sea water and the water vapor in the adjacent air is already in equilibrium. I sincerely doubt that they have taken the water high enough that the bucket needed to evaporate to reequilibrate.
But, water temperatures are mild compared to air temperatures. So as they wait for a reading, the water should be cooling in winter or heating in the summer. In the latter case, evaporation is a secondary response, slowing down the heating.
These people seem to have invented a new form of refrigeration. Take a large body of water, pull up a bucket of it, and the water in the bucket magically cools itself.
There is one other graphic at the House of Hansen which is noteworthy. This is the temperature history of the (lower 48) United States. This was a favorite of John Daily because the United Sates had the best network of surface stations on the planet, as made as they are.
http://data.giss.nasa.gov/gistemp/graphs/Fig.D.lrg.gif
As reported at Climate Audit and this website, Dr. Hansen and gone to great lengths to make “homogeneity adjustment” to this data so that it would yield the desired results. I am going to be very interested to see what the data for 2008 shows on this graphic.
Mike
Steamboat Jack:
During his brief stint in the USN back in the ’80’s my friend remarked how darn cold the hull was even down next to the boilers.
This publish-or-perish data half-bakery looks awfully desperate to me. Anything to clean up unexplained anomalies, it’s like rectifying the Ptolemaic system with epicycles. That Newton was just as guilty of cramming epicycles into his celestial model just goes to demonstrate how tempting such chicanery is. Sometimes some phenomena are best left unexplained until better science can address current perturbations. And some data are best left as mysteries never to be solved.
Bob Tisdale,
Bob, this is excellent work. http://bobtisdale.blogspot.com/2008/05/will-corrections-to-global-temperature.html
Could you also show the trend lines without the PDO scaling factor?
It might be a 2nd project, but if the point of this exercise is in seeing what trend line is left after all the noise is canceled from the various other natural sources, it’d lend to a hierarchical linear regression that’d leave us with the CO2 signal. Other efforts I’ve seen leave a very marginal effect (Jan Janssens has a similar effort on his website).
Solar forcing would have increased ocean temperatures, el Nino & AMO+ magnitudes over the past century until about 1990-1995, when the sun started dimming again. I would assume then that PDO & AMO magnitudes could be phase adjusted. Perhaps it’s feasible to, in a stepped fashion, de-noise the solar impact on the troposphere, PDO & AMO which in turn would provide their own subtractive phase adjustments against the general trend. PDO & AMO perturbations put back into the solar column would leave CO2 or other factors in the PDO & AMO column, etc.
I’m guessing the remaining trend line would leave noise from two remaining factors: Aerosols (which in fact cause a net warming — see Ramanathan & Carmichael, 2008), soot deposition in the Arctic (19 percent of all AGW since 1850) and CO2 (with its natural effect Temperature = Temperature0 + ln(1 + 1.2x + 0.005x^2 + 0.0000014x^3) ).
I have *yet* to see a warmist explicate the contributory phase adjustments on the various climate factors.
It may also be notable that the ionosphere contributes terawatts of energy into the global environment, potentially stronger at the poles.
This looks too much like, “the data doesn’t fit the model, therefore, the data must be wrong.” Now, I’ll grant you that the data might be flawed, but in light of recently observed repeated tweaking of data that doesn’t conform to models, this latest episode looks suspicious. An honest scientist would be hitting the models as well to find their flaws. And while the above graph shows some smoothing, it still shows that some cooling happened during that period up to the mid-70’s.
The models might attain a degree of credibility if they could forecast such long-lived phenomena as the decadel oscillations in the Atlantic, Arctic, and Pacific Oceans. They must also show the impact of solar activity on climate and not make the unwarranted assumption that because we’ve experienced a certain similar though varying level of solar activity over past century, that such activity will continue into the future. This assumption is sure to haunt the modelers in coming decades as solar activity declines to levels not seen in over a century.
Warming somehow becuase cooler is jsut wrong to even suggest let alone put on a official AGW graph.
I’m getting confused here. The modelers have spent the last decade telling us how great the match between model output and historic temperature trends have been. Now we see a substantial change to about 20 years of the historic record, and we are being told that this change dramatically improves the match between the historic record and the output of the models.
If the match was already great, how come there was need of a substantial improvement?
These people seem to have invented a new form of refrigeration. Take a large body of water, pull up a bucket of it, and the water in the bucket magically cools itself.
They’re canvas buckets. Here in Australia we used to put water in a canvas bag and hang it in the breeze. It would cool very rapidly. The stronger the wind, the quicker the cool. If there was a breeze at sea, or if the ship was traveling (I read that they often were for these bucket hauls – hard on the arms!), then the water in the canvas bucket would start cooling the moment it broke the surface. How fast I don’t know, but I know that water in canvas cools pretty damned quick.
I see from the graph that the peak difference is 0.2C. They kept the thermometer in for three minutes – that’s after hauling the bucket out of the water, so let’s say the bucket was getting sea breeze for 3 and a half minutes. Doesn’t sound too far fetched to me that this resulted in a measurable drop. How much capacity did they have?
The article’s pretty vague on the terminology. ‘Global temperature’? Is that ocean temps, land and ocean, surface temps?
It’s rarely useful to haggle over the science in a newspaper article.
Hey, my memory works!
http://en.wikipedia.org/wiki/Coolgardie_safe
The contraption there at wikipedia is pretty fancy. The ones I’ve seen are just the canvas bag hanging in the shade. It would cool to pretty chilly even on scorching days if there was a bit of a breeze. First time I saw one and had a drink from it, it did seem like magic.
If you have a canvas bag of the right weave, a thermomoeter and a low spinning fan, you could do your own experiment right now. Take the temperature of the water (whatever volume they used to pull up the side of the boat) from a solid container, transfer to canvas bag, turn on the fan (move it to a distance you think would be an average wind-speed for a boat at sea, allowing for traveling speed etc), stick the thermometer back in for three and a half minutes and see if there’s a difference. You’d want to approximate the shape and size of the canvas bucket, too. If it’s thin, the water cools more quickly.