This new paper in GRL takes on the well-known buckets-vs-inlets issue (Steve McIntyre also visited the issue several times) related to ship based sea surface temperature measurements and as a result, produces an improved dataset. The results show a surprising period of warming, but not in the time period expected. How would AGW advocates explain that most of the warming in the near surface layers of the ocean came well before Dr. Hansen’s supposed “safe” value of 350ppm of CO2 in Earth’s atmosphere. How would they account for the big rise before 1940?
Even more interesting, if you look at panel (b), (surface temperature in red) you see essentially no change from over 100 years ago. The shape and slope of Panel (a) looks much like the BEST and other surface data up until the mid twentieth century, then post WWII population growth set in. The differences between the two sets post 1980 (when we have the best measurements) is quite stark:
Here’s the paper:
Consistent near-surface ocean warming since 1900 in two largely independent observing networks
Viktor Gouretski, John Kennedy, Tim Boyer, and Armin Köhl
We compare historical global temperature time series, based on bias-adjusted sea-surface temperatures with independent temperature time series, for the upper 20 meter layer
of the ocean based on the latest update of an historical hydrographic profile data set. Despite the two underlying data sets being different in number of data points, instrumentation and applied adjustments, both of the time series are consistent in showing an overall warming since 1900.
We also extend records of temperature change in the upper 400 m back to 1900. Noting that the geographic coverage is limited prior to 1950, the temperature change in the 0–400 m layer is characterized by two periods of temperature increase between 1900 and 1940–45 and between 1970 and 2003, separated by a period of little change. Citation: Gouretski, V., J. Kennedy, T. Boyer, and A. Köhl (2012), Consistent near-surface ocean
warming since 1900 in two largely independent observing networks,
Geophys. Res. Lett., 39, L19606, doi:10.1029/2012GL052975.
Introduction
Numerous studies have identified an overall rise of the surface temperature of the Earth since the nineteenth century [Smith et al., 2008; Hansen et al., 2010; Morice et al.,
2012]. The global-average surface temperature is estimated from a composite dataset that includes both land- and seasurface temperature (SST) observations. In addition to studies
analyzing surface temperature data, collections of historical hydrographic temperature profiles have been used to estimate the change in heat content of the global oceans
[Levitus et al., 2005, 2009, 2012; Gouretski and Koltermann, 2007].
Two main sources of uncertainty affect both the surface and subsurface time series based on in situ data. The first is related to insufficient data coverage both in space and time, with extremely irregular sampling in the earlier parts of the records. The second arises from instrumental biases which can be comparable in magnitude to real variability in the
climate. Jones and Wigley [2010] identified biases in SST measurements as the most important remaining uncertainty associated with estimating global average temperature change.
Prior to the 1980s, SST measurements were mostly made using buckets or in the engine rooms of ships. Folland and Parker [1995] described systematic errors in SST observations
associated with the use of uninsulated buckets for water sampling and developed adjustments. Uncompensated biases associated with a shift in the database from engine room measurements (relatively warm biased) to bucket measurements (relatively cold biased) occurred at the end of World War II and led to an apparent drop in observed SSTs in late 1945 [Thompson et al., 2008]. More recent studies [Kennedy et al., 2011a, 2011b] attempt to quantify SST biases and their associated uncertainties in the post war period.
However, Kennedy et al. [2011b] note that “Until multiple, independent estimates of SST biases exist, a significant contribution to the total uncertainty will remain unexplored. This remains a key weakness of historical SST analysis”.
Gouretski and Koltermann [2007] revealed significant biases both in the eXpendable BathyThermograph (XBT) and in the Mechanical BathyThermograph (MBT) data used
to measure subsurface ocean temperatures. The effect of this instrumentation problem appeared as an artificial pattern of ocean warming around 1975–1985 in the Levitus et al.
[2005] time series of ocean heat content within the upper 700 meters. Further studies have confirmed the general characteristics of the biases described by Gouretski and
Koltermann [2007] and correction schemes have been developed for both MBT and XBT data [Wijffels et al., 2008; Ishii and Kimoto, 2009; Levitus et al., 2009; Gouretski and
Reseghetti, 2010].
However, Lyman et al. [2010] showed that even in the recent record (1994–2008) the uncertainties of the bias adjustments applied to subsurface data were a major component of the total uncertainty in estimates of ocean heat content. It is often difficult to assess the effectiveness of bias adjustments in reducing the imprint of systematic errors in climate data because independent test data are rarely available. In this analysis an initial approach to resolve this uncertainty is made by comparing two independently derived estimates of near-surface ocean temperature. In addition, a time series of the mean temperature within the upper 400 meters of the world ocean is calculated back to 1900.
[…]
Conclusions
1. The time series of the temperature anomalies within the upper 20-meter and 400-meter layers were extended to the beginning of the twentieth century, although there are
gaps around the two world wars for the 0–400 m layer. Previous estimates started around 1950.
2. A good agreement is observed between the time series based on the sea surface and the near-surface data respectively, but differences suggest either residual uncertainty
of around 0.1C in the adjustments applied to minimize the effects of systematic errors, or actual differences between temperatures at the sea-surface and in the upper 20 meters.
3. The upper 400 meters of the ocean warmed by about 0.3–0.7C since 1910, with a central estimate around 0.5 to 0.6C. The temperature change is characterized by
two periods of stronger temperature increase between 1900 and 1940–45 and between 1970 and 2003, separated by a period of little change in the global average.
4. Decadal mean SST and 0–20 m layer anomalies calculated relative to the reference decade 2001–2010 give evidence of the general warming of the global ocean since
1900. However, large regions of the oceans have experienced cooling since the 1990s. Whereas cooling in the tropical Eastern Pacific ocean is associated with frequent La
Nina events in the past decade, the cause of the cooling within the Southern Ocean remains unknown.
h/t to Dr. Leif Svalgaard, who has a copy of the paper online here.
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It needs to be repeated for those staring at these graphs that the zero-anomaly line is essentially meaningless.
Of course, there are people who that think their being alive on planet Earth confers upon the climate system of the past century a magically deep significance.
Maybe the BBC are slowly seeing the light?
http://www.bbc.co.uk/news/science-environment-19848112
From about 1910 to 1940, we saw a significant global warming. This was then followed by a hiatus and then it warmed again to temperatures we saw in the the period around the 1930’s. The extent to which modern land temperatures exceed those of the 1930’s is simply an artifact of “adjustments”. I am not convinced we have seen any global temperatures exceed those of 1934.
Re George says. Born on 07/05/1926, I can well remember the mid thirties in Southern England and Southern Ireland being hotter than any period since then.
Thanks for the link to the paper, Anthony and Leif.
Hopefully, the new datasets will be updated to the KNMI Climate Explorer soon.
The conclusion of the paper includes: “However, large regions of the oceans have experienced cooling since the 1990s…”
And we showed that the sea surface temperatures for 75% of the surface area of the global oceans haven’t warmed in agreement with climate models since 1993 here:
http://bobtisdale.wordpress.com/2012/09/20/a-blog-memo-to-kevin-trenberth-ncar/
And in the YouTube video included here:
http://bobtisdale.wordpress.com/2012/10/03/we-now-control-weather-extreme-heat-events-dirty-weather-climate-disasters/
With all due respect….(love that phrase!)
With all due respect, I as a matter of course, in the course of my work, measure the temperatures of air, gases and liquids.
I use highly accurate, professional, calibrated equipment both digital and analog.
You know what?
Every time I read someone’s solemn assertion that the ‘Global’ SST in 1820 was…something POINT something degrees, or 1900 ‘Global’ Land temperature was something POINT something degrees…. I am torn between laughing at them and wanting to smack them across the head!
Global Temperature Natural Variability
An image easy to remember
http://www.vukcevic.talktalk.net/EarthNV.htm
Earth has its ‘zing’ originating in the core and the sun has its cycles.
When two are in phase the oceans absorb more energy, when two are out of phase the oceans cool.
Jean Dickey of NASA’s Jet Propulsion Laboratory, Pasadena:
One possibility is the movements of Earth’s core (where Earth’s magnetic field originates) might disturb Earth’s magnetic shielding of charged-particle (i.e., cosmic ray) fluxes that have been hypothesized to affect the formation of clouds. This could affect how much of the sun’s energy is reflected back to space and how much is absorbed by our planet. Other possibilities are that some other core process could be having a more indirect effect on climate, or that an external (e.g. solar) process affects the core and climate simultaneously.
vukcevic says:
October 7, 2012 at 12:59 pm
“Jean Dickey of NASA’s Jet Propulsion Laboratory, Pasadena: […] Other possibilities are that […] an external (e.g. solar) process affects the core and climate simultaneously.”
I have not gotten around to reading and looking at it in detail yet, nor done quantitative calculations to check plausibility for the timeframes and inertia involved, but, in case you might be interested, the authors of a paper including the following excerpt may be pursuing a partially related path of investigation:
“When the changes of the interplanetary magnetic field induced by solar wind exceed a certain threshold, by virtue of the Faraday law of electromagnetic induction they can become the reason for origin of inductive currents in the Earth liquid core. In other words, when the eccentricity verges toward its local maximum the magnetic flux variations of interplanetary field can cause the considerable variations of the Earth magnetic field, which, in its turn, are capable to induce electric current in the Earth liquid core. Such an additional current, which by virtue of the Le Chatelier law is oppositely directed relative to direction of convection current in the Earth liquid core, can partly disable the convection responsible for the Earth magnetic field generation.”
Such and further discussion is within a paper at
http://arxiv.org/abs/0803.2766
where the full-text pdf link is
http://arxiv.org/pdf/0803.2766v3
And part 1 of the paper is:
http://arxiv.org/abs/0803.2765
http://arxiv.org/pdf/0803.2765v3
It is important to see that the temperature variations are most pronounced in the near surface region and not at the surface.
That feature suggests that the culprit is the amount of solar energy able to pentrate past the evaporative layer at the ocean surface.
A warmer atmosphere cannot do that nor can increased so called back radiation.
So, clearly to me at least, we must look to the amount of solar energy getting into the oceans and that is intimately connected to global cloudiness and albedo.
The pre 1940 increase on near surface warmth is coincident with solar cycles 17, 18 and 19.
The subsequent pause coincides with weaker cycle 20.
The subsequent resumption of warming coincides with stronger cycles 21, 22 and 23.
Obviously (to me) solar activity affects global cloudiness and albedo and thus the amount of energy entering the oceans to fuel the climate system.
I have already described the mechanism by which that is achieved.
Would someone explain the blue Near-Surface plot in 1b? I must be misinterpreting this in some manner that, in the 1920’s, the temperature at that depth was varying about 20°C (±10°C) year-by-year and I assume seasonal variance, yet in the post 2000 temperatures they now only varies about 2°C? Then you look at figure 1c and the 2-sigma uncertainty is only 2°C in the 1920’s? Really? WUWT? The analysis goes on digging deeper from that point on but I can’t without some further explanation of what we’re look at.
Three peaks are visible in HADSST2
1878, 1944 and 1998.
66 years apart (or close enough).
1878 0.000
1944 0.095
1998 0.451
Keep in mind that 2011 = 0.273 barely higher than 1944 or 1878.
http://www.cru.uea.ac.uk/cru/data/temperature/hadsst2gl.txt
wayne says: “Would someone explain the blue Near-Surface plot in 1b? I must be misinterpreting this in some manner that, in the 1920′s, the temperature at that depth was varying about 20°C (±10°C) year-by-year and I assume seasonal variance, yet in the post 2000 temperatures they now only varies about 2°C?”
With a global dataset that’s complete, different parts of the globe are responding at different times so they they will cancel or dampen one another. There are fewer observations as you go back in time, and most of those observations were confined to shipping lanes, so there is less and less data from other areas to dampen or oppose those observations.
Henry Clark says: October 7, 2012 at 1:41 pm
……
Mr. Clark
Thank you for the info, I shall follow it up. I have suspected that the solar-Earth magnetic fields link is very likely, as confirmed by the (inverse) correlation between two, despite vigorous opposition from some experts,
http://www.vukcevic.talktalk.net/TMC.htm
OK.
So, do we not HAVE to factor one more “recent change” into the Land-Based Temperature record for the last 50 years?
If, as CAGW theists maintain, the earth’s net (or “average” or “theoretical-single-worldwide”) temperature anomaly is ONLY a function of net albedo, net total solar radiation in, and net IR (earth-to-space) radiation out …
We know that the recent increases in CO2 levels have caused every green plant on earth to grow 13% to 27% more rapidly, in more areas, and with wider, thicker branches, stems, and leaves.
Why do we “assume” that the land (or sea) albedo has remained the same?
didn’t the ice cores indicate that the oceans warm up some 800 years (on average) BEFORE the CO2 rises? This would look like it tracks that observation – warm ocean burps up CO2 (and other dissolved gases).
“if you look at panel (b), you see essentially no change from over 100 years ago. “
I think that’s an effect of the axis scale. For near-surface it’s an extraordinary change – from 5°C to 20°C. I agree with wayne – we’d need to know more about that. Bob T suggests that they are measuring in different places. That makes the plot pretty useless – another reason why anomalies are better.
REPLY: I was referring the surface temperature in red in panel b, updated for clarity – Anthony
“Even more interesting, if you look at panel (b), you see essentially no change from over 100 years ago. The shape and slope of Panel (a) looks much like the BEST and other surface data up until the mid twentieth century, then post WWII population growth set in. The differences between the two sets post 1980 (when we have the best measurements) is quite stark: ”
huh?
Figure 3 is the chart you want to look at to see the differences between early periods and later periods. relative to the base period of 2000-2010 the first decades are 1.2 C cooler and .76C cooler ( 0-20m and SST respectively )
Some notes.
1. They use IDW. There are better methods
2. More data is a good thing, especially from other sources.
3. In ICOADS there are just as many MAT (marine air temperature ) records as SST records. There is no reason to combine STT and SAT for a global average. One could combine MAT and SAT for the global air average. But for some weird historical reason Hanson combine SST and SAT for the global average. Just a thought for folks who are interested.. That is to say, looking at the change in MAT from 1950 on will be instructive and may rule out various conjectures and speculations.
REPLY: I was referring the surface temperature in red in panel b, updated for clarity – Anthony
Wilde:
“Obviously (to me) solar activity affects global cloudiness and albedo and thus the amount of energy entering the oceans to fuel the climate system.”
Unfortunately, the hypothesis that solar activity “affects” “global” cloudiness, has no well defined empirical data for its support and no working proven physics to support it.
To support that you will need.
1. A well defined and audited historical record of “solar activity” whatever that means.
2. A well defined and audited historical record of “cloudiness” whatever that means.
3. A physical model ( as in equations ) to test. Mere correlation isnt science.
It possible, of course, but I’ve yet to see anything that rises above the level of “mannian” science.
vukcevic says:
October 7, 2012 at 2:14 pm
I have suspected that the solar-Earth magnetic fields link is very likely, as confirmed by the (inverse) correlation between two, despite vigorous opposition from some experts,
http://www.vukcevic.talktalk.net/TMC.htm
Yes, and this is why Leif’s magnetically derived solar series diverges from the sunspot count. The cancelling effect of the opposite phases irons out the apparent solar variation calculated from the deflections of the magic magnetic needle.
Which is why a number of solar-terrestrial experts don’t accept Leif’s attempted revision of sunspot numbers.
http://tallbloke.wordpress.com/2011/07/16/does-sunspot-number-calibration-by-the-magnetic-needle-make-sense/
K. Mursulaa, , , I. Usoskinb and O. Yakovchouka, 1
aDepartment of Physical Sciences, University of Oulu, Finland
bSodankylä Geophysical Observatory, University of Oulu, Finland
Accepted 18 April 2008.
Available online 10 May 2008.
Abstract
It has been suggested recently that early sunspot numbers should be re-calibrated and significantly corrected using the observed daily range of the geomagnetic declination (so-called rY values). The suggested “correction” method makes an a priori detrending of the rY series and then extends the linear regression between rY and sunspot numbers established for the last 25 years to earlier times. The suggested “correction” of sunspot numbers by roughly 30% goes far beyond the traditional estimates of observational uncertainties of sunspots. Concentrating here on Zürich sunspot numbers (Rz), we demonstrate that the rY values do not actually imply that the observed Rz values in the 19th century are systematically underestimated. Rather, we find that the Rz numbers are fairly uniform after mid-19th century. The suggested “correction” is largely induced by the detrending of the rY series, which enhances the rY-based sunspot activity in the 19th century relative to later times. We also show that while the annually averaged declinations have a rough relation between sunspots and other related solar parameters, this relation is strongly seasonally dependent and, therefore, not sufficiently accurate or uniform to allow annually averaged rY values to be used as a very reliable proxy of solar activity in early times.
The paper can be purchased here: http://www.sciencedirect.com/science/article/pii/S136468260800117X
There is a very interesting fine structure to Southern Ocean (from 30S) atmospheric CO2 levels if one calculates residuals relative to the ‘official’ NOAA global average. This also applies to individual Northern Hemisphere (NH) and Southern Hemisphere (SH) monitoring stations such as Mauna Loa (MLO).
Over the period 1982 – 2007 CO2 levels at MLO were always greater than the global average. For MLO 1998 was an obvious peak in exceedance of the global CO2 average but despite the fading of the large 1998 El Nino, at least until 2007 the trend for MLO seemed to be for an increasing margin above the global average.
Conversely, over the period 1982 – 2007 CO2 levels over the Southern Ocean were always lower than the global average. For the Southern Ocean 1998 was not a special year with respect to the negative residuals for CO2 levels i.e. below the global average.
Over the period 1982 – 2007 the (negative) residual of CO2 levels over the entire Southern Ocean relative to the global mean has trended towards greater (negative) values. In other words, over 1982 – 2007, CO2 levels over the surface of entire Southern Ocean (below 30S) have slowly lagged increasingly below the (rising) global average surface CO2, falling from about 0.35% below the global average to above 0.55% below it in recent years – a counter trend of about -0.1%/decade against the (always rising) global average CO2 level.
Similarly, the CO2 residual below the global average over the Southern Ocean has now approached close to the long term average residual at the Easter Island Station (EIC), which has always typically lagged about 0.65% below the global average CO2 level since records (at EIC) commenced in 1994. The Easter Island Station is located near the center of the Southwestern Pacific Gyre – a region of high cyanobacterial productivity and a well-known (and studied) high level of persistent cloudiness.
As I see it, the only logical explanation for this trend is that cyanobacterial productivity (which abstracts CO2 and bicarbonate from surface waters) over the entire Southern Ocean is steadily increasing (relative to the past and relative to the global oceanic productivity average). It is likely therefore that the degree, and persistence, of cloud cover over the entire Southern Ocean is increasing in response to increasing atmospheric CO2. Hence it may be inferred that global albedo is also increasing as a biogenic negative feedback to AGW.
If someone could tell me how to post a graph I can show them the data upon which the above statements are based. All data is from NOAA. I would be happy to post it to e.g. YouSendiT for anyone who emails me. FYI, I have not seen any peer-reviewed paper identifying and discussing this long term, and continuing, trend despite careful and periodic seaching over the last 5 years.
If the ocean near surface temps really increased by 15 degrees Celsius between 1900 and 1940 (as suggested by panel b) we do indeed have reason to be quite alarmed.
beesaman says:
October 7, 2012 at 11:44 am
Maybe the BBC are slowly seeing the light?
http://www.bbc.co.uk/news/science-environment-19848112
Exactly the opposite of what the same outfit (the University of Reading Dept of We Haven’t a Clue) were saying 5 years ago:
Dr Peter Stott, a climate scientist at the University Of Reading and co-author of the paper, said: “The paper is saying there is a significant human influence on global rainfall patterns and this includes an increase of precipitation north of 50 degrees northern latitude, an area that includes the UK.
“In the UK wetter winters are expected which will lead to more extreme rainfall, whereas summers are expected to get drier.
Source:
http://www.telegraph.co.uk/science/science-news/3301412/Man-made-global-warming-increases-rainfall.html
Steve Short says: If someone could tell me how to post a graph I can show them the data upon which the above statements are based.
I have never been able to get WP not to screw up any attempt to get an image included in a post. Maybe that is intentional. All I can suggest is putting the graph somewhere else, like tinypic.com , for example, and then you just add the URL and WP makes it into a link automatically.
What you describe looks interesting, please post links to data too.
By stretching the charts verticall one can make several interesting onservations. Trend lines eyeballed in Chart a). Coolng from 18xx to about 1909/10, then warming to ca 1945, cooling to 1976, warming to 2005. Curiously there seems to be a warm plateau from about 1940 to 1955 and from 1997 to 2012. The real post peak cooling should be about to start now. Total warming from 1910 to 2005 (1.5 cycles) is about 1 degree C. Warming from 1900 to 2000 is 0.6 degrees C. 2005 peak is about 0.3 degrees C warmer than 1945 peak. (I suspect there is still a little warming bias). Eyeballed warming trend 1910 to 1945 is almost exactly parallel with 1976 to 2005.
One century is about 10 years longer than 1.5 cycles, so does not give the total 1.5 cycle warming of 1 degree C. 100 year warming is between 0.6 and 0.9 degrees C/century depending on start and end dates chosen.
Chart b) seems to show warming of 4 degrees C valley to peak, but does not have tenths of degree scale. These 2 charts need to be reconciled.
[Consider copying this and re-editing it into separate lines: It will be easier to follow. Mod]