Washington Post Headline: “Worlds fish have been moving to cooler waters for decades, study finds”

This is an addition to the post Fishy Temperature Proxy by Anthony Watts.


A new paper about fish migration patterns from 1970 to 2006 is getting some attention by the press. My Figure 1 is Figure 2 from Cheung et al (2013). Click it to enlarge it.

Figure 1 Cheung et al Figure 2

Figure 1

As usual, global warming enthusiasts in the press overlook some basic issues—like the sea surface temperatures for the Indian and Pacific Oceans from pole to pole haven’t warmed in 19+ years, and the Atlantic data show little warming for more than a decade. Further, the tropical Indian and Pacific sea surface temperatures haven’t warmed since 1986. It’s therefore difficult to make claims like “more evidence of a rapidly warming planet”, but that doesn’t stop proponents of hypothetical human-induced global warming.


Anthony Watts presented the press release for the paper Cheung et al (2013) Signature of ocean warming in global fisheries catch in the WattsUpWithThat post Fishy Temperature Proxy. And ClimateDepot’s Marc Morano alerted me earlier in the day to Lenny Bernstein’s May 15th article in the Washington Post. See “Worlds fish have been moving to cooler waters for decades, study finds”. The first two paragraphs of Bernstein’s article read (my boldface):

Fish and other sea life have been moving toward Earth’s poles in search of cooler waters, part of a worldwide, decades-long migration documented for the first time by a study released Wednesday.

The research, published in the journal Nature, provides more evidence of a rapidly warming planet and has broad repercussions for fish harvests around the globe.

Rapidly warming planet? Maybe the author of the Washington Post article should check sea surface temperature data before making nonsensical comments.

The University of British Columbia press release for the Cheung et al (2013) paper is titled “Fish thermometer” reveals long-standing, global impact of climate change. The opening two paragraphs of the press release provide a good overview of the paper:

Climate change has been impacting global fisheries for the past four decades by driving species towards cooler, deeper waters, according to University of British Columbia scientists.

In a Nature study published this week, UBC researchers used temperature preferences of fish and other marine species as a sort of “thermometer” to assess effects of climate change on the worlds oceans between 1970 and 2006.

I found no explanation in the paper about why they ended the study period in 2006 for a paper published in 2013 or, phrased another way, why they overlooked the most recent 6 years of sea surface temperature data. That aside…


As noted in the introduction, the sea surface temperature anomalies of the Indian and Pacific Oceans from pole to pole (90S-90N, 20E-70W) haven’t warmed in 19 years. See Figure 2. The sea surface temperature anomalies for this major portion of the global oceans obviously warmed during the study period, 1970 to 2006, but they show no warming if the data is extended to current times and if we start the trend analysis in January 1994. In other words, the sea surface temperature data for about 70% of the surface of the global oceans provide no indication of warming for almost 2 decades.

Figure 2

Figure 2

That leaves us with the Atlantic data. It also shows warming from 1970 through 2006, but if we examine the data from January 2002 to January 2013, the trend has been remarkably flat—which suggests a possible slowdown in the warming rate of the sea surface temperatures in the Atlantic, too. It’s a little early to tell there, though, because there have been similar decadal slowdowns in the rate of warming in the Atlantic since 1970. It’s only a matter of time there, though. Eventually, the Atlantic Multidecadal Oscillation will cause the sea surface temperatures in the North Atlantic to peak, flatten and then start to cool—as it has for hundreds if not thousands of years. See NOAA’s FAQ webpage about the AMO.

Figure 3

Figure 3

The press release provides a link to a Pew Charitable Trusts – Environmental Initiatives overview of Cheung et al (2013). There they state (my boldface):

The authors found that, except in the tropics, catch composition in most ecosystems slowly changed to include more warm-water species and fewer cool-water species. In the tropics, the catch followed a similar pattern from 1970 to 1980 and then stabilized, likely because there are no species with high enough temperature preferences to replace those that declined. Statistical models showed that the increase in warm-water species was significantly related to increasing ocean temperatures.

What they forgot to tell you was that the sea surface temperatures of the tropical Indian and Pacific Oceans (24S-24N, 35E-80W) warmed drastically in response to the 1976 Pacific Climate Shift, see Figure 4, and then have remained relatively flat since then. In fact, the sea surface temperatures of the tropical Indian and Pacific Oceans show no warming since 1986, or for more than 2 ½ decades.

Figure 4

Figure 4

So where’s the “rapidly warming planet”?


Usually, peer-reviewed papers identify what datasets were used in the study. This courtesy appears to have been overlooked in Cheung et al (2013). Figure 2 in Cheung et al (2013) suggests a sea surface temperature dataset that has been infilled, because the trend analysis maps in their Figure 2 show data in the high latitudes of the Southern Hemisphere. And they also refer to the Hadley Centre’s sea surface temperature climatology in the paper. But for sea surface temperatures, Cheung et al (2013) don’t cite the expected Rayner et al (2003) for HADISST. They cite Belkin (2009) Rapid warming of large marine ecosystems, which cites Rayner et al (2003).


The Cheung et al (2013) paper hasn’t yet received the normal end-of-the-world-as-we-know-it hype from the alarmist blogs Climate Progress and SkepticalScience. It’s still a little early, though. Give Climate Progress and SkepticalScience a little while before they join the Washington Post, where Lenny Bernstein elected to make the claim of a “rapidly warming planet”. As so often happens, claims about warming sea surface temperatures are not supported by sea surface temperature data.

And of course, ocean heat content and satellite-era sea surface temperature data indicate the oceans warmed naturally. If this topic is new to you, refer to the illustrated essay “The Manmade Global Warming Challenge” [42MB].

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May 16, 2013 7:15 pm

Sorry Bob. As soon as I read the “Journal”, no need to carry on. I could write their peer-reviewed propoganda in my sleep.

May 16, 2013 7:28 pm

Fish populations are an interesting subject. There has definitely been some serious over-fishing, especially by the former Soviet Union back in the 1950-1980 period, and the damage they did to fish stocks, (and to the sea bottom, in places,) caused a derangement of the ecosystem, and that system still seems out of kilter, using the standards of “how the fishing used to be.”
I don’t think the “experts” understand what exactly is going on. Considering a single female codfish lays 4 million eggs, the codfish population off the coast of New England seemingly ought to have bounced back swiftly, but it has remained unchanged, even when they cut back on how many fish are allowed to be netted, more and more.
The deranged ecosystem likely has some species which thrived when the population of codfish shrank, and in some ways replaced the codfish’s niche in the ecosystem. Also there may be some tiny critter that just loves codfish eggs, which is thriving in the warm AMO. Or perhaps one of a multitude of other factors are involved.
In any case the ecosystem is in a state of flux and transition, and using it for any sort of proxies seems fraught with danger. Proxies require a stability which is utterly lacking in the oceanic ecosystem at all times, and especially now.
For example, every La Nina leads to rich up-welling off the coast of Peru, and fish populations boom. However sometimes the big boom is in the anchovies population, and sometimes it is the sardines. They haven’t figured out why it is one fish one time, and another fish another time. A mystery is involved, and the mystery occurred even back in colonial times, when no over-fishing was involved.
I love mysteries, but mysteries make lousy proxies.

May 16, 2013 7:49 pm

I second the motion:
“I love mysteries, but mysteries make lousy proxies.”
Just a flawed paper and an even more flawed ‘peer-review!’

Rud Istvan
May 16, 2013 7:49 pm

Much is fishy here. But not how cold nutrient rich upwelling bottom dwelling waters increase fish food supplies which then (unbelievable science!) attract fish. That, after all, is how South American fishermen came to name El Niño (when it doesn’t happen).
This discussion including of the paper seems to be, to quote the Bard, Much Ado About Nothing.

Tom J
May 16, 2013 7:58 pm

Let us take a look at who Mr. William Cheung is. According to his biography:
‘William is an Assistant Professor at the UBC Fisheries Centre since 2011. William obtained a BSc. (Biology) in 1998, and subsequently a M.Phil. in 2001 from the University of Hong Kong. After working in WWF Hong Kong for two years, he moved to Vancouver and completed his PhD in Resource Management and Environmental Studies in the UBC Fisheries Centre in 2007. He then worked as a postdoctoral fellow in the Sea Around Us project for two years. From 2009 to 2011, he was Lecturer in Marine Ecosystem Services in the School of Environmental Sciences, University of East Anglia in the UK.’
What the foregoing leads me to believe is that he doesn’t know diddly-squat about fish. For some not very surprising reason I see positively nothing in his academic description that even remotely alludes to the idea he might possibly be an ichthyologist. Did I just say there wasn’t a very surprising reason not to expect him to have ichthyologist hiding somewhere in his résumé? Could it be because he was a lecturer in Marine Ecosystem Services in the School of Environmental Sciences, University of … East Anglia? My, my that university gets around. And it sure seems to house, feed, and caress an exclusive club. And the more I see of this tight knit bunch I realize that none of them are genuine specialists in the areas they attempt to bamboozle us.

A Crooks
May 16, 2013 8:31 pm

I’m confused here. Why would fish move to cooler waters? If they liked cooler waters they could have all swum to the poles during the Devonian and just stayed there. Wouldn’t they move to waters of the same temperature? In which case why not just show the changes in water temperature and be done with it?

May 16, 2013 8:36 pm

Following up on Tom J’s comment, my experience is, if you want to identify a fish, best to look at a fishing reference book rather than an academic one.
My view is, this lot are …. lying scum. [edit if necessary]

May 16, 2013 8:52 pm

Miles long and thousands of foot deep gill nets, pulled by industrial fishing ships that strip the entire marine ecosystem of life are no laughing matter, and the probable cause of the remaining fish moving to the food, or safety of the depth. However, this and the preceding “Fishy Temperature Proxy” indicates that today’s topic is funny fish stories, so my favorite….
An old man goes out to a lake to fish one day, baits his hook and casts into the water. He hears a voice….
“Pick me up”
Looks around, doesn’t see anything, then hears the voice again….
“Pick me up”
He looks down and sitting on lilly pad is a frog, who clearly says….
The old man reaches down, picks up the frog who then says….
“If you kiss me i’ll turn into a beautiful princess and be with you for the rest of your life”
The old man pauses….”Ummm”….sticks the frog in his shirt pocket….
The frog panics….
“Didn’t you hear me ? Kiss me and i’ll turn into a PRINCESS ! ! !”
The old man opens his pocket and says….
“At my age i’d rather have a talking frog”
I think we are all done with the AGW princess….kindly give us back our functional science….
BTW….a talking frog would be far better conversation than a climatologist.

May 16, 2013 9:13 pm

I know for a fact that in the EU zone fisheries are being over-fished/depleted and have been for decades not because fishery supply can’t meet demand it’s purely because of stupid EU regulations, quotas and quotas on certain fish. Any fish caught that is not in the quota, it’s thrown back into the sea, dead of course. Estimates for this waste are something in the order of 1.5 million tonnes annually.

Janice Moore
May 16, 2013 9:33 pm

[Just a little bit of the fish tale to give you an idea of its flavor]
“Study Methods
Dr. William Cheung of the University of British Columbia … They assigned each species a temperature preference based on the average sea surface temperature in areas where that species was predicted to have occurred between 1970 and 2000. … researchers determined the connection between ocean warming and changes in fisheries catch by using a statistical model that separates out other factors, such as fishing effort and oceanographic variability.
Statistical models showed that the increase in warm-water species was significantly related to increasing ocean temperatures.
Earlier research led by Dr. Cheung predicted continuing changes in fish distribution and catch as oceans warm (Cheung et al. 2010). … Additional impacts could include … conflicts over new fisheries that emerge because of distribution shifts</b … .”
[Emphasis mine.]
Source: http://www.pewenvironment.org/news-room/fact-sheets/warming-oceans-are-reshaping-fisheries-85899475142
Key line of entire abstract: “
new fisheries that emerge because of distribution shifts.
Thus, (granting, ad argumentum, that fish are even migrating due to warming ocean water) this (as stated above by others) IS NOT A REAL PROBLEM.
Thus, (again, ad argumentum) the mystery [indeed, Caleb], continues.
Oh, Mycroft? Mycroft?? Where is that deuced brother of yours? Out at East Anglia doing drugs with the Climatologists? Oh. Pity. Well, somebody, ring up Poirot, would you? =|(:})[–)K

Tom Harley
May 16, 2013 9:34 pm

Must be time to panic, it’s not just fish, but whales too: http://pindanpost.com/2013/05/12/more-non-science-at-murdoch-university-and-canberra/ the pocket liners need more funding.

May 16, 2013 9:40 pm

As with many other commenters I’d like to see something in the paper that accounts for an increase in human fishing activities in recent decades and indeed overfishing. If the fishermen are fishing more in temperate areas then unsurprisingly fish that can live on both temperate and colder waters will be see in greater relative proportions in the colder waters where there are fewer fishermen

Janice Moore
May 16, 2013 9:46 pm

“‘At my age I’d rather have a talking frog.'” LOL, Joseph Olson — great fable.
And, then, the old man sold his talking frog to Michael Mann et. al. who upon its answering, “No” to the query: “Can humans alter earth’s climate?” smashed it over the head with his hockey stick, killing it. Then, he turned it into a hand puppet, er “model.” Now, Mann and Hansen and all their buddies carry it all over the world, charging a lot of money to hear their frog “talk.” When little kids ask them why their lips move when the puppet talks, they bring out the AGWer’s favorite explanation: “SHUT UP!” [from Ring Lardner’s “‘Shut up,’ he explained.”]
“Well, what in the world does that pupp-, er model say?” You may ask. ANYTHING.
Thanks, Bob Tisdale, for keeping us in the real world where data is data and facts are facts.

Tom Harley
May 16, 2013 9:48 pm

Researchers are clueless when it comes to fish and water temperatures. Every diver knows that temperature can vary by a few degrees in just a few feet change in depth, or a few feet further out. Professional fisherman look for those boundary changes all the time, because that’s where the pelagics hang out. Some like it hot: http://pindanpost.com/2013/02/21/propaganda-heating-up-now-its-scorched-fish/

May 16, 2013 9:52 pm

Hello Bob
Tangentially, I am planning to do an upgrade/update to the WUWT ENSO Reference page;
and in researching it I came across these NOAA Nino 3.4 and 4 Region Sea Surface Temperature Anomaly graphs that extend back ~ 112 Years:
Nino 3.4 Region Sea Surface Temperature Anomaly 1900 – 1953
Nino 3.4 Region Sea Surface Temperature Anomaly 1950 ~ 12-Jun-2012
Nino 4 Region Sea Surface Temperature Anomaly 1900 – 1953
Nino 4 Region Sea Surface Temperature Anomaly 1950 ~ 12-Jun-2012
Not sure why they decided to split the graphs at ~ 1950,… Are you familiar with the data set/s that these graphs are based upon? Do you have a sense for how accurate the data is, especially during the first half of the last century? Do you think the 1900 – 1953 graphs are WUWT Reference Page worthy? Do you see any issues with combining the two graphs to show the full 112 years?

Rhys Jaggar
May 16, 2013 10:05 pm

If you followed their arguments, any man seeing a horny woman should have a 25ft penis by daybreak, always assuming you caught the ‘rising libido’ index at the critical times………
Stock markets would only ever rise, never fall.

May 16, 2013 10:32 pm

Okay kids…one more fish story….
This couple are in bed watching TV one night….and the husband has the remote control….
as things should be….he keeps changing the channel….
Finally the wife says….
“Will you STOP that….that is SO annoying”
Husband says….”stop what”‘
Wife says….”Look just pick one channel or the other”
Husband…”Well….fine….since it’s your suggestion….why don’t you pick the channel”
Wife….”Fine….let’s watch porn”
Husband…”And WHY do you….want to….watch porn ? ? ?”
Wife…”Cause….you already know how to FISH”
BTW….If there are any talking frogs out there….i’m interested.

Michael Tremblay
May 16, 2013 10:39 pm

One of the things I’ve noticed about biologists studying fish behaviour – they rarely talk to fishermen. Fishermen have known for centuries that fish migrate based on the thermal water currents – following the food supplies.

May 16, 2013 11:53 pm

Fish don’t move to cooler waters. The move to waters that are comfortable or less turbulent, or cleaner, or dirtier, or which have more food, or have less fish poo, or is more or less cloudy – who really knows. They don’t move to cooler waters or they would always have been in those cooler waters. Unlike climate scientists fish are not stupid. They go where it is best suited for fish of their ilk. And also unlike climate scientists, fish are both understand adaption and are adaptable. Hell, even muskox understand this and migrate. Someone please tell me why oh freaking why this natural adaption is news.
This needs to go back on page one on all the pro-human climate blogs. Dig deep.

May 17, 2013 1:45 am

Fish follow food. Small fish follow the plankton, that food follows the currents. bigger fish follow the smaller fish. Sea creatures above the bottom of the food chain simply go where the food is rather than move to a more ‘comfortable’ spot.
Sure fish can seem to migrate to cooler waters at certain times of the year, every coastal fisherman knows you need to wait until at least November before you have any chance of catching cod off the south west coast of England. That’s because the cod arrive, with the food around then.

May 17, 2013 2:22 am

Could mean that over fishing releases more food so new species take over that area. ”Tropical” fish actually swim in water of varying temperatures, ie. GBR species can be found in the cool south and warm north.

May 17, 2013 3:17 am

Yet another study which starts with 1960’s/1970’s as a starting point.

Bloke down the pub
May 17, 2013 3:24 am

I’m not expecting to see as many bass caught in the English Channel this year compared to the last few years. Still too cold for them.

the amateur
May 17, 2013 4:18 am

This is sort of like deja vu all over again. Doesn’t anyone remember that the PDO was discovered by a fisheries researcher who found the ~60 year cycle in the fish catch off the western coast of the US? Seems fish have been tracking their preferred waters (probably following the food) for years.

May 17, 2013 5:12 am

Fish have always had a preference for cold water. As any marine biologist or physical chemist can tell you, the colder the water the more dissolved gas it can hold.
Ice water can hold up to 3.3 g O2 per liter, twice what it can hold at 20° C. This is great news for phytoplankton, which convert CO2 into marine biomass, for zooplankton, which eats the phytoplankton, and larger animals which eat the smaller animals.
Now you might understand why whales migrate from pole to pole – that’s where all the food is!
Less obvious is the reason whales breed in warmer waters. The calves are more vulnerable to hypothermia.

Just an engineer
May 17, 2013 5:47 am

Rhys Jaggar says:
May 16, 2013 at 10:05 pm
If you followed their arguments, any man seeing a horny woman should have a 25ft penis by daybreak, always assuming you caught the ‘rising libido’ index at the critical times………
Stock markets would only ever rise, never fall.
Actually, using Cli-Sci-Fi methodology an occilating stock market would rise.
Example: $100 stock increases $10 to $110 one week and then falls $10 over the second week. This is a 10% increase in week one and a 9.1% drop the second week. You have a net gain of .9% after 2 weeks. Just imagine a doubling of your money in only 2 years!d Why would someone not invest with them?!?!

Pat Michaels
May 17, 2013 7:33 am

The Post article makes the claim, based on the press release from Pew, that clam populations no longer commercially viable in Virginia are now being harvested in New England. Given that the study runs from 1970 through the present, this means that coastal Maine must now have the climate of Tidewater Virginia of the 1970s. In fact, NCDC records show that the current average temperature in the coastal Maine CD now is running about 7.5degC, while the early 1970s temp in the tidewater Virginia CD was 14.5. Absolute complete failure of the simplest hypothesis.
I sent this to Len Bernstein at the Post–in a nice, cheery note–and I don’t think I will be hearing anything back. I also sent it in a letter to the Editor. Think they will print it?
Pat MIchaels

May 17, 2013 7:57 am

The paper by Cheung et al (2013) stresses fish migration patterns from 1970 to 2006 and claims that this is a general trending that will last in the future.
This claim, however, is quite misleading. The major reason is that only data covering the period from 1970 to 2006 are studied in Cheung et al (2013).
On the contrary, there exists a large scientific literature stressing a quasi 60-year oscillation in the climate and marine system. The 60-year oscillation is quite evident in indexes such as the Atlantic Multidecadal Oscillation (AMO), the North Atlantic Oscillation (NAO), the Pacific Decadal Oscillation (PDO).
A quasi 60-year oscillation is commonly found in fish commercial stocks once longer records than the 36-year 1970-2006 period are analyzed, e.g. in
Klyashtorin, L. B., Borisov, V., and Lyubushin, A.: Cyclic changes of climate and major commercial stocks of the Barents Sea. Mar. Biol. Res., 5, 4–17, 2009.
The failure of recognize the natural 60-year oscillation in the climate system is a typical error encountered in the scientific literature predicting alarming scenarios for the 21st century, for example in the sea level rise.
Two recent scientific papers authored by me discuss extensively this issue and highlight the error:
1) Scafetta N., 2013. Multi-scale dynamical analysis (MSDA) of sea level records versus PDO, AMO, and NAO indexes. Climate Dynamics. in press. DOI: 10.1007/s00382-013-1771-3.
2) Scafetta N., 2013. Discussion on common errors in analyzing sea level accelerations, solar trends and global warming. Pattern Recognition in Physics, 1, 37–57.
Paper (1) discusses the importance of the ocean oscillations (since 1700). Paper (2) in section 2 discusses the case of the sea level rise in New York and how it has been misinterpreted in other papers by misinterpreting the bending of the 60-year cycle. Paper (2) discusses also other typical mathematical errors in interpreting climatic records.
Visit my web-page for additional comments about the 60-year oscillation, etc.

Gary Pearse
May 17, 2013 8:08 am

Since LWIR (the main heating radiation) doesn’t penetrate down to the fish and ultraviolet does, maybe with the fish are swimming north and south to thin out the UV intensity. This would be an easy experiment to do. This U of W must have an CAGW dictator at the top.

Gary Pearse
May 17, 2013 8:17 am

Gary Pearse says:
May 17, 2013 at 8:08 am
Since LWIR (the main heating radiation) doesn’t penetrate down to the fish and ultraviolet does, maybe with the fish are swimming north and south to thin out the UV intensity.
Well what do you know? Here is a link to a paper that found UV does cause migration of fish! Hey I’m only an engineer, but a better ichthyologist than they turn out at Hogwash U.

May 17, 2013 2:16 pm

“Climate change has been impacting global fisheries for the past four decades by driving species towards cooler, deeper waters. . .”
How can the deeper waters be cooler? I thought Trenberth and NCAR said all the missing heat is down there.

May 17, 2013 7:44 pm

Bob Tisdale says: May 17, 2013 at 3:15 am
The suppliers like NOAA and the Hadley Centre who create the reconstructions then apply the bucket, etc., “corrections”…
…and infill missing data.

Those are some interesting corrections… According to the Hadley Centre:

The SST data are taken from version 2.5 of the International Comprehensive Ocean-Atmosphere Data Set, ICOADS (external web page), from 1850 to 2006 and on GTS observations from 2007 onwards. HadSST3 is produced (a slightly more detailed description) by taking in-situ measurements of SST from ships and buoys, rejecting measurements that fail quality checks, converting the measurements to anomalies by subtracting climatological values from the measurements, and calculating a robust average of the resulting anomalies on a 5° by 5° degree monthly grid. After gridding the anomalies, bias adjustments are applied to reduce the effects of spurious trends caused by changes in SST measuring practices. The uncertainties due to under-sampling and measurement error have been calculated for the gridded monthly data as have the uncertainties on the bias adjustments following the procedures described in the paper. http://www.metoffice.gov.uk/hadobs/hadsst3/

Here’s the paper “Improved Analyses of Changes and Uncertainties in Sea Surface Temperature Measured In Situ since the Mid-Nineteenth Century: The HadSST2 Dataset”, Rayner, et al., 2005:
Within it it states that:

a. Bias correction and its uncertainties Seawater has been sampled for temperature measurement on board ship by various different means at different times. This change from using insulated (wooden) to uninsulated (canvas) to partly insulated (rubber) buckets, engine room intakes, and hull sensors, along with changes in ships speeds, has introduced changing relative biases into the database. Folland and Parker (1995) developed corrections to be applied to SST data between 1856 and 1941 to ameliorate the effect of these changes and to bring the older data into line with data from the modern mix of measurement methods. For details of the development of these corrections, the reader is referred to Folland and Parker (1995).

Here’s Parker, Folland, M. Jackson (1995):
Here are some of the corrections:

“Overall global warming in SST between the 1860s and the 1970s is about 0.3 °C greater in the present analysis than in Folland et al. (1984), mainly owing to reduced early corrections applicable under the assumption of the predominant use of wooden buckets (Section 3).”
“The largest, positive corrections are in early winter (December) over the Gulf Stream and the Kuroshio, where warm water, cold dry air, and strong winds cause rapid evaporative heat loss from the buckets. The corrections approach 1 °C by 1940 in these regions in early winter. Corrections are also large (around 0.4 °C to 0.5 °C by 1940) in all seasons in the tropics because of the high rate of evaporation when SST is high. Some negative corrections are made in mid latitudes in summer, mainly where the mean air temperature around the bucket exceeds the mean SST.”
“How do we know that these corrections are trustworthy? The agreement of SST anomalies with largely independently corrected NMAT anomalies (Section 7 and Figure 7) is the strongest support to the results, and suggests that the impacts of future refinements and reduction of uncertainties in this area will be small.”
“Folland et al. (1984) applied corrections to NMAT to compensate for the historical increases of the average height of ship’s decks. These rose from about 6 m before 1890 to 15 m by the 1930s and 17 m by the 1980s. The corrections, based on surface layer similarity theory, removed a spurious cooling of about 0.2 °C between the late nineteenth century and 1980. On the other hand, Jones et al. (1986) used anomalies (not actual values) of regional, mainly coastal, land surface air temperature to adjust anomalies of nearby MAT. This was possible because anomalies of MAT and nearby ‘coastal’ land surface air temperature are found to be similar in recent data over periods as long as a decade, even though the absolute values differ considerably. However, because Jones et al. (1986) used COADS summaries, they were unable to separate NMAT from day MAT which are affected by historically varying, on-deck solar heating: their corrections therefore differed from those of Folland et al. (1984). In both these early studies, about 0.5 °C was subtracted from MAT for 1942-5, a period of non-standard measurement practices owing to war. “

Here’s their Fig 7. Which shows the impact of the adjustments:
It turns out that Rayner, Folland and Parker all worked at the Hadley Centre, Met Office, Exeter EX1 3PB, UK;
So I dug a little deeper, and look who showed up; “Corrections to Pre-1941 SST Measurements for Studies of Long-Term Changes in SSTs” P. Jones and T. Wigley, Climatic Research Unit, University of East Anglia, Norwich NR4 7TJ, UK

Many factors can influence a sea surface temperature reading (Barnett, 1985; Jones et al., 1986; Bottomley et al., 1990; Jones et al., 1991). Some of these introduce random errors while others result in systematic, non- cancelling errors. The most important factor is the method of collecting the sample, with the two basic methods being to haul a sample on deck with a bucket, or to measure the temperature of the intake water used for engine cooling. Here, we are concerned with bucket measurements. These are affected by the kind of bucket used, the exposure of and physical conditions surrounding the bucket, how long the bucket was left before reading the thermometer,and ship speed.
In COADS we do not have detailed information concerning the methods of measurement, nor anyindication of what method was used for the individual readings that make up the data. There is,nevertheless, strong evidence that readings before 1940 were predominantly bucket measurements, while those since 1945 were predominantly intake measurements (Jones et al., 1986). Furthermore, it is likely that the major difference between the data for these two periods is the non-climatic bias due to the evaporative cooling of the canvas bucket, an effect which would clearly cause pre-1940 data to be cooler than post-1945 data (Jones et al., 1991).
In order to derive correction factors for the bucket-derived temperatures, we have modified the model developed by Folland and Hsiung, 1987 and Bottomley et al., 1990, to estimate the cooling of an un-insulated canvas bucket. The main difference between our work and that of Folland and Hsiung (1987) is that we have solved the governing equations analytically. This makes applicationof the model less demanding computationally, and it allows us to perform a variety of analyses.
2. The bucket model

If you have not already, you should look at “The Bucket Model” in Jones and Wigley’s paper, as it is a classic work in gibberish:

4. Correcting SSTs using the bucket approach
“4.1 Optimum exposure time
For 1905-40, SSTs may be corrected using the evaporating bucket model. Although average ship speed probably varied over this period, within the range of likely values ship speed does not noticeably affect the implied exposure time. We have used a ship speed of 7ms-1. Wind speeds of 60% of the anemometer speed produce slightly better results than the 40% reduction case, and lead to slightly lower optimum exposure times (by less than 1 minute on average) so we have used this value. As the most likely exposure time lies in the range 3-6 minutes, we use 4 1/2 minutes in making final corrections.”
“4.2 The final correction factors Final correction factors depend on the location, month and year. These variations are summarized in Figures 3 to 5. Correction factors vary slightly from year to year depending on coverage changes. Figure 3 shows mean correction factors for the Northern Hemisphere. Southern Hemisphere mean corrections are shown in Figure 4. The transition from small corrections in the early decades to larger corrections after 1905 is due to the change from wooden (i.e., better insulated and assumed to require no correction) to un-insulated buckets. Correction factors are largest in the winter half year. Northern Hemisphere corrections show slightly larger season-to-season variations. Figure 5 shows how the “winter” (JFM) and “summer” (JAS) – using Northern Hemisphere seasonal labels – corrections vary with latitude. Correction factors are lower in higher latitudes in general, particularly in the 45-75°N band where the “summer” corrections are near zero.”

Here Jones and Briffa team up to summarize it for us, “Global Surface Air Temperature Variations During the Twentieth Century: Part 1, Spatial, Temporal and Seasonal Details P. D. Jones and K. R. Briffa, 1992 Climatic Research Unit, University of East Anglia, Norwich NR4 7TJ, UK”

“Problems with the homogeneity of sea surface temperature (SST) data arise due to differences in the method of sampling the sea water. Before the second world war the sea water was collected in an uninsulated canvas bucket, There was a delay of a few minutes between sampling and measuring the temperature. During this time the water in the bucket generally cooled slightly by evaporative means. Since the second world War most readings have been made in the intake pipes through which sea water is taken onboard ships to cool the engines. This change in measurement technique was quite abrupt at around 194112, although there are still significant numbers of bucket measurements (using plastic and thus better insulated buckets) made today and some intake measurements were made prior to the second world war.
Comparative studies of the two methods indicate that bucket temperatures are cooler by 0.3-0.7″C (James and Fox, 1972). Correcting the SST data for this measurement change may seem, at first, seem an intractable problem. Folland and Parker (1990; 1991) of the UK Meteorological Office, how- ever, have developed a method for correcting the canvas bucket measurements based on physical principles related to the causes of the cooling. The cooling depends on the prevailing meteorological conditions, and so varies according to the time of year and location. Although the cooling is therefore a day-to-day phenomenon, the various influences are basically linear, so cooling amounts can be calculated on a monthly basis. The main free parameter is the elapsed time between sampling and reading. This is generally unknown and must be estimated from the data. The primary assumption in this estimation is that there have been no major changes in the seasonal cycle of SSTs over the period of record. Since the amount of evaporative cooling has a strong seasonal cycle in many parts of the world, an optimum exposure time can be chosen; namely that which minimizes the residual seasonal cycle in the corrected data. As a check on the validity of the method, the implied optimum exposure time turns out to be quite consistent spatially (see Jones and Wigley, 1990; Jones et al., 1991 for more details).
The major problem with the technique is that it is not known with any certainty what types of buckets were used to take measurements during the nineteenth century. Assuming canvas buckets rather than wooden buckets (which are better insulated) leads to corrections which infer SSTs warmer than land temperatures by about 0.2″C. The discrepancy almost disappears if wooden buckets are assumed. Although there is documentary evidence to support wooden bucket use during the mid-nineteenth century, considerable doubt remains about the transition from wooden to canvas buckets. The seasonal-cycle elimination method is not precise enough to choose between the two possibilities. The corrections used here have been derived using the wooden bucket assumption in the nineteenth century (see Jones et al., 1991 for details).

Steve McIntyre has written extensively about bucket adjustments since 2005, i.e.:

You may recognize Folland as a major IPCC author (Folland et al. [2001] is sometimes the citation). SST sampling is not homogeneous – it changed from buckets to engine inlets – engine inlet temperature ran a little hotter. Both canvas and wooden buckets appear to have been used. There are millions of SST measurements and how the measurement was done is not known for most measurements (as far as I can tell.) There are two main adjustments in Folland et al. The first is a one-time adjustment for from buckets to engine inlets in December 1941. This is premised on a comparison between the “corrected” NMAT temperature [ I haven’t checked what these “corrections” are] and the uncorrected SST temperatures.

Buckets and Engines
The Team and Pearl Harbor
Bucket Adjustments: More Bilge from RealClimate
Rasmus, the Chevalier and Bucket Adjustments
Did Canada switch from Engine Inlets in 1926 Back to Buckets?

CA readers are aware that I discussed bucket adjustments on a number of occasions long before Thompson et al 2008, in particular, questioning the absurd IPCC assumption that all SST measurements switched from buckets to engine inlet on the day after Pearl Harbour. In March 2007, a year before Thompson et al 2007, in light of new historical information bucket usage, I provided a scoping estimate of the potential impact of a different changeover scenario, based on then-just-published Kent et al 2007. The direction of the impact is precisely the same as that shown in the present HadCRU estimates over 4 years later. The difference between the two appears to be that the present HadCRU estimate assumes that bucket changeover impact has ended by 1970, while, in my 2007 post (based on Kent’s evidence of widespread bucket usage in the 1970s), I presumed that the changeover continued until the 1990s.”


A new HadSST3 version has been recently published. It starts the process of unwinding Folland’s erroneous Pearl Harbour bucket adjustment, an adjustment that has been embedded in HadSST for nearly 20 years.
Folland’s erroneous adjustment had been originally criticized at CA in 2005 here and further discussed at length in March 2007 at CA here, a post in which I observed that no climate scientist had made any attempt to validate Folland’s bizarre adjustment and that correcting Folland’s error (through a more gradual and later changeover to engine inlets than the worldwide overnight change that Folland had postulated after Pearl Harbour) would have the effect of increasing SST in the 1950s, in turn, potentially eliminating or substantially mitigating the downturn in the 1950s that was problematic for modelers.
However, not until Thompson et al 2008 (submitted Jan 2008; published May 2008) was the problem with the Folland adjustment clearly acknowledged by the “community”. The importance of Thompson et al in resolving the problems arising from the Folland adjustment were credited by Susan Solomon and Phil Jones in the commentary accompanying the Nature article.) Both lead author David Thompson and co-author Mike Wallace, though very prominent climate scientists, had negligible (or no) publishing history on the topic; as one commenter at James Annan’s blog put it, they came out of “left field”. Thompson was an ozone specialist. The other co-authors, John Kennedy of the Hadley Center and Phil Jones of CRU, were, of course, actively involved in the field.
Now over three years later, in a new SST edition (HadSST3), the Hadley Center has accepted and implemented Thompson et al’s criticism of Folland’s Pearl Harbour adjustment. Instead of implementing an overnight changeover to engine inlets in December 1941 as before, the changeover is now phased in through the mid-1970s. This results in changes to SSTs between 1941 and ~1975.

However, Steve has not really dug that far into the pre-1940 rise highlighted in your graph.
One piece of this puzzle I can’t seem to find is the oft cited Bottomley et al., 1990, i.e, Bottomley, M., C. K. Folland, J. Hsiung, R. E. Newell, and D. E. Parker, 1990: Global Ocean Surface Temperature Atlas. MIT Press, 20 pp. plus 313 plates.

This is the January 1993 version of the Global Ocean Surface Temperature Atlas (GOSTA, Bottomley et al., 1990) referred to as ATLAS7 or MOHSST5. The data in this atlas are a compilation of marine observations from the United Kingdom Meteorological Office Main Marine Data Bank with some additional data from the US Fleet Numerical Oceanography Center. The Atlas includes the climatology of sea surface temperature (SST) and the difference between marine nighttime air temperature (NMAT) and SST. These climatologies are based on data collected between 1951 and 1980. Also included are SST and NMAT monthly anomalies from 1856 to 1991. The data were corrected to remove what are believed to be observational biases due to changes in instrumentation. These correction are based on scientific research summarized in the introduction to the hard-copy version of GOSTA (Bottomley et al., 1990). All data are presented on a 5 by 5 degree grid wherever data existed. The climatology of SST can be made available on a 1 by 1 degree grid.
The quality of marine observations is thoroughly discussed in the hard copy volume of GOSTA as well as in the references therein. The user should note that the data were collected using a variety of instruments and observational procedures aboard vessels of different shapes and dimensions.

Here is the GOSTA Data:
I would really like to find this; “These correction are based on scientific research summarized in the introduction to the hard-copy version of GOSTA (Bottomley et al., 1990).” but even Google Scholar comes up dry:
All very interesting, I may post an article and use your SST graph at the head of it…
I’ll let you decide whether you want to include the graphs of the earlier pre-1950s data on the WUWT ENSO page, but, as you know, I do present it. Examples:

I like the second graph, however would prefer if you could remove the blue box from the bottom of the graph and host it on bobtisdale.wordpress.com/, as I avoid “editorializing” on the reference pages and prefer that all graphs be hosted by their creator/source, i.e. not tinypics.
It helps to show that there were also some pretty strong El Niño events in the early part of the record, too–though Giese et al (2009) indicates the 1918/19 portion of the 1918/19/20 El Niño was comparable in strength to the El Niños of 1982/83 and 1997/98, and that the 1911/12 and 1939-41 El Niños may also have been stronger.

Frankly, you know this area much better than I, and I want to be careful that I don’t mislead anyone, thus would you be open to serving as an advisor/resident expert on the WUWT ENSO Reference Page? Would you be open to collaborating on a crowdsourcing thread to update/upgrade the ENSO page, i.e. we post a bunch of new potential graphs and graphics in an article, we solicit addions and input, you provide your recommendations on inclusion, exclusion, changes to order, graph labels, etc. and I’ll make the changes to Reference Page as we go?

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