The Impact of the North Atlantic and Volcanic Aerosols on Short-Term Global SST Trends

Guest Post From Bob Tisdale

PRELIMINARY NOTE

I took this post from the prior one “A Secondary (Repeated) ENSO Signal?” and added to the narrative because it is worthy of its own post. I’ve also added long-term trend comparisons at the end to illustrate a point.

INTRODUCTION
I prepared a post on SST trends for the globe, Figure 1, and for individual ocean subsets. (That post has now been put to the side.)
http://s5.tinypic.com/24f0j8x.jpg
Figure 1

The disparity between the North Atlantic SST anomaly trend, Figure 2, and the rest of the subsets was striking. The North Atlantic SST anomaly linear trend for the period of November 1981 (the start of the OI.v2 SST dataset) and January 2009 is ~0.264 deg C/decade, while the global linear trend is ~0.0948 deg C/decade. The North Atlantic linear trend is approximately 2.8 times the global linear trend, driven by Atlantic Meridional Overturning Circulation and El Ninos, (yes, El Ninos).
http://s5.tinypic.com/x23xis.jpg
Figure 2

NOTE: El Nino-induced step changes in the North Atlantic were illustrated in the post There Are Also El Nino-Induced Step Changes In The North Atlantic. Recall, also, that the Atlantic Meridional Overturning Circulation appears to be impacted by ENSO events as well. Refer to the post titled Atlantic Meridional Overturning Circulation Data.

REMOVING THE NORTH ATLANTIC DATA

So I decided to remove the North Atlantic SST anomaly data from the global. There is no simple way to do this with a coordinate-based system such as NOMADS or KNMI Climate Explorer, so I made an assumption. The Atlantic Ocean surface area is approximately 30% of the global ocean surface area, and I assumed the North Atlantic represented 50% of that. I then scaled the North Atlantic SST anomaly data by 0.15 and subtracted it from the global SST anomalies. The resulting dataset, noted as “Global SST Anomalies Without North Atlantic,” is illustrated in Figure 3. There isn’t a significant difference between the peaks and troughs of this adjusted dataset and those of the global SST anomalies. Visually, the curve appears as though it’s been rotated. What stands out, however, is the decrease in trend to 0.0546 deg C/decade.
http://s5.tinypic.com/2ihuot0.jpg
Figure 3

REMOVING THE EFFECTS OF VOLCANIC AEROSOLS

Volcanic aerosols lower the SST anomalies at the time of the eruption and for a few years afterwards, so SSTs would have dropped as a result of the 1982 El Chichon and 1991 Mount Pinatubo eruptions. This increased the trend over the term of the dataset. Figure 4 is a comparative graph of the “Global SST Anomalies Without North Atlantic” and inverted Sato Index of Stratospheric mean optical thickness. I’ll use the Sato Index data to remove the impacts of the volcanic eruptions.
http://s5.tinypic.com/4r5f8y.jpg
Figure 4

If we consider that the peak of the decrease in global land plus sea surface temperature caused by the Mount Pinatubo eruption is considered to be between 0.2 to 0.5 deg C, the 0.15 deg C illustrated at 1991 would be toward the conservative side for SST. Eyeballing it, it appears to be in line, so there doesn’t seem to be any need to scale the Sato Index data. I then added the Sato Index to the “Global SST Anomalies Without North Atlantic” data. The resulting changes in the “Global SST Anomalies Without North Atlantic” data is shown in Figure 5. Note how the trend has decreased to 0.036 deg C/decade.
http://s5.tinypic.com/al1yth.jpg
Figure 5

LONG-TERM SST DATA

Figures 6 and 7 are long-term comparisons of global SST anomaly data and the global SST anomaly data with the North Atlantic and the effects of volcanic aerosols removed. Figure 6 uses ERSST.v2 SST anomaly data and Figure 7 uses HADISST SST anomaly data. I used the same scaling factors that I used in the short-term data. All datasets have been smoothed with 37-month filters (but the trends were determined from the unsmoothed data, which is why the trend lines extend beyond the smoothed curves). For ERSST.v2 Global SST anomaly data, the linear trend from January 1880 to January 2009 is approximately 0.040 deg C/decade, but with the North Atlantic and volcanic aerosols removed, the linear trend drops to approximately 0.033 deg C/decade. A similar drop results with the HADISST SST anomaly data, with the Global SST anomaly linear trend dropping from 0.041 deg C/decade to 0.035 deg C/decade when the North Atlantic and volcanic aerosols are removed. Note that over the period of 1880 to 2008 there is no significant change in the trends caused by volcanic aerosols. The Mount Pinatubo and Krakatau eruptions were approximately the same magnitudes, both had a DVI of 1,000, so they would tend to “balance” one another at opposite ends of the period.
http://s5.tinypic.com/2mrvfyx.jpg
Figure 6
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http://s5.tinypic.com/2q0vhj4.jpg
Figure 7

A CLOSING NOTE ABOUT TRENDS

The Global SST anomaly trend from November 1981 to January 2009 is approximately 0.0948 deg C/ decade or 0.95 deg C/century. Without the natural variations in North Atlantic SST anomalies and without the impacts of two significant volcanic eruptions, the SST trend would project out to a rise of only 0.36 Deg C over the next 100 years, which is more in line with the long-term trends.

Figure 8 is the upper half of “FAQ 3.1, Figure 1” from the IPCC’s “Frequently Asked Question 3.1 – How are Temperatures on Earth Changing?”
http://www.gcrio.org/ipcc/ar4/wg1/faq/ar4wg1faq-3-1.pdf

The caption reads, “Note that for shorter recent periods, the slope is greater, indicating accel­erated warming. The blue curve is a smoothed depiction to capture the decadal variations. To give an idea of whether the fluctuations are meaningful, decadal 5% to 95% (light grey) error ranges about that line are given (accordingly, annual values do exceed those limits). Results from climate models driven by estimated radiative forcings for the 20th century (Chapter 9) suggest that there was little change prior to about 1915, and that a substantial fraction of the early 20th-century change was contributed by naturally oc­curring influences including solar radiation changes, volcanism and natural variability. From about 1940 to 1970 the increasing industrialisation following World War II increased pollution in the Northern Hemisphere, contributing to cooling, and increases in carbon dioxide and other greenhouse gases dominate the observed warming after the mid-1970s.”
http://s5.tinypic.com/vowo7c.jpg
Figure 8

Are the IPCC taking advantage of the natural cycles of Atlantic Meridional Overturning Circulation and of periodic volcanic eruptions to illustrate “ACCELERATED WARMING” in more recent decades?

Of course they are!

SOURCES

OI.v2 SST data can be accessed through the NOAA NOMADS system:
http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?lite

ERSST.v2 data and HADISST data can be accessed through the KNMI Climate Explorer website:
http://climexp.knmi.nl/selectfield_obs.cgi?someone@somewhere

The Sato Index Data is available from GISS at:
http://data.giss.nasa.gov/modelforce/strataer/
Specifically:
http://data.giss.nasa.gov/modelforce/strataer/tau_line.txt

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65 thoughts on “The Impact of the North Atlantic and Volcanic Aerosols on Short-Term Global SST Trends

  1. That linear “curve fit” bothers me!

    What is the standard deviation of that data set.

    If the SD is high enough (appears it might be), despite the seeming “upward trend”, statistically the “trend” may be “not significant”.

    A quick check for “normallity” of the data (distribution wise, there are about 8 standard “normallity” checks out there. Then a check for the S.D., and an analysis to would see if we really can see that linear “upward trend” or if it could be “just noise”.

    P.S. this is NOT an emotion or “hidden agenda” comment. This is just a suggestion, which I would like to see BROADLY applied to all of these curve fitting exercises, particularily with “short range” data, i.e. 10 to 100 years.

  2. Hi, Anthony:

    This one was too much for me to follow, but this early remark struck me:

    There is no simple way to do this with a coordinate-based system such as NOMADS or KNMI Climate Explorer, so I made an assumption. The Atlantic Ocean surface area is approximately 30% of the global ocean surface area, and I assumed the North Atlantic represented 50% of that.

    Did you mean that you want to determine which coordinates (of data values) are IN the Atlantic Ocean? A simple GIS tool – some are free – could do that.

    L

  3. I have to ask the same question as the surfacestations project: How do they measure temperature, and to what accuracy? What are the local biases? How do they calibrate or check for sensor drift over time? Obviously using lots of sensors, shipboard data. To 0.1 C or better? Of course, it’s an ‘anomaly’, so all relative, which still doesn’t eliminate measurement errors.

    Averaging 10 readings with 1 degree accuracy does not give you 0.1 degree.
    Neither does averaging 100 readings. It depends on the source of the error.

    Good thread, but I question the raw data.

  4. The IPCC’s cherry picking of start and end dates on the last graph is comprable to your cherry picking geographic locations.

  5. Mark Hugoson: I don’t want to appear non responsive to your comment, but…

    I am one of the handful of bloggers who download SST anomaly data, create graphs of the SST anomaly data, add them to videos of oceanic processes, and discuss them. I rarely click on the Analysis and Trend buttons on EXCEL and add linear trends to the graphs. In this case, I did. I used the short-term trends to illustrate a few points:
    -That the North Atlantic was the dataset with the highest recent linear trend,
    -That the North Atlantic has a significant impact on Global SST anomaly linear trend,
    -That the Volcanic eruptions of El Chichon and Mount Pinatubo also impact the linear trend, and
    -That the IPCC, who also use short-term trends, by failing to account for the natural variability of the North Atlantic and the effects of volcanic aerosols, exaggerate their claims of accelerated warming due to anthropogenic forcings.

    With that in mind, statistics are not among my strengths. If you’d like to analyze the data further, there are instructions for downloading the data at the bottom of this link, along with the coordinates for the North Atlantic dataset:
    http://bobtisdale.blogspot.com/2009/02/secondary-repeated-enso-signal.html

    Further information about the Reynold’s Optimally Interpolated Sea Surface Temperature data can be found here:
    ftp://podaac.jpl.nasa.gov/pub/sea_surface_temperature/reynolds/oisst/doc/oisst.html

    Regards

  6. Talking about the raw data.
    There is an article published at icecap.us now by Arno Arrak,
    “Satellite Data Show No Warming Before 1997. Changes Since Not Related to CO2”

    You can download the PDF of the article but here is the conclusion:

    Arrak Executive Summary
    1. Satellite records show that global temperature does not vary randomly but oscillates with a peak‐to‐peak amplitude of 0.4 to 0.5 degrees Celsius and a period of three to five years about a mean value that remains constant. Examination of land‐based data indicates that such temperature oscillations have been
    active, with some irregularities, as long as records have been kept.

    2. The mean temperature about which these oscillations swing remained the same during the eighties and nineties, showing absence of global warming for this period. But simultaneous land‐based measurements (HadCRUT3) show a warming of 0.2 degrees Celsius for that same period. Both cannot be correct.

    3. Cause of these global temperature oscillations is a periodic movement of ocean waters from shore to shore, associated with the El Nino – Southern Oscillation or ENSO system. This is accompanied by massive back and forth transfers of heat between the oceans and the atmosphere which was previously unsuspected and which shows up in all world temperature records. The absence of this major
    atmospheric phenomenon from IPCC global circulation models (GCMs) invalidates such models. Hence, any climate assessment based on these models is based on nothing more than GIGO.

    4. Normal ENSO temperature oscillations were suddenly interrupted from 1997 to 1999 by a giant warming peak, attributed to the “1998 super El Nino.”

    5. This unusual warming interrupts the oscillatory ENSO system and straddles its La Nina phase. After it has subsided the ENSO oscillations pick up again without missing a beat. Having absorbed energy from that “El Nino that should not be there,” however, global temperature now rises to a peak 0.2 degrees above that of previous peaks.

    6. But the oscillatory downturn that should follow it fails to occur and a six‐year warm period – the “twenty
    first century high” – begins. Effective world temperature during this warm period is 0.4 degrees above the
    effective temperature that existed before the 1998 peak. This warming, with the 1998 peak, and not some trace amount of carbon dioxide in the air, are jointly responsible for accelerated loss of arctic ice. The warm period ends with a temperature downturn in 2007. This in turn bottoms out in 2008 and the
    temperature is now on the rise again.

    7. Since the energy of that 1998 warming peak did not come from the ENSO system it is entirely unaccounted for and could well be cosmogenic. Gamma ray burst GRB 971214 is a possible candidate source.

    8. All land‐based temperature records such as HadCRUT3 that show late twentieth century warming in the eighties and nineties when there was none are inflicted with massive systematic errors. The usual suspect is the urban heat island effect. The fact that land areas have tended to warm faster than ocean areas and winter months more than summer months (IPCC 2007) points in that direction.

    9. Finally, a word about Al Gore and the IPCC Nobelists. I am sorry to say that the emperor has no clothes on. A trace amount of carbon dioxide in the air does not cause global warming as required by their religion.
    There was no warming in the eighties and nineties and the warming that does exist started only in 1997, is entirely different in kind, and is not understood. Time for them to close down that Kyoto shrine of theirs and start doing some real climate science.

    It would be nice to project the findings of this post to the raw data from Arno.

  7. Lichanos: You wrote, “Did you mean that you want to determine which coordinates (of data values) are IN the Atlantic Ocean?”

    No, sir. The coordinate-based systems such as NOMADS or KNMI Climate Explorer allow the user to download data for specific coordinates. They do not allow you to extract a dataset that you don’t want from it before downloading. In this case I wanted the Global SST anomaly data without the North Atlantic. So I had to extract it manually, which is no big deal. I simply noted why I had to go through a manual process.

    Retired Engineer: You wrote, “I have to ask the same question as the surfacestations project: How do they measure temperature, and to what accuracy? What are the local biases? How do they calibrate or check for sensor drift over time? Obviously using lots of sensors, shipboard data. To 0.1 C or better? Of course, it’s an ‘anomaly’, so all relative, which still doesn’t eliminate measurement errors.”

    From the Optimally Interpolated SST data website:
    ftp://podaac.jpl.nasa.gov/pub/sea_surface_temperature/reynolds/oisst/doc/oisst.html

    “The NCEP Reynolds Optimally Interpolated (OI) Sea Surface Temperature product consists of weekly and monthly global sea surface temperature fields on a 1 degree by 1 degree grid. The analysis uses both in-situ SSTs and satellite derived SSTs from the NOAA Advanced Very High Resolution Radiometer (AVHRR). The satellite derived SSTs are from the Multichannel Sea Surface Temperature products that have been constructed operationally from the five-channel AVHRR by NOAA’s Environmental Satellite, Data, and Information Service (NESDIS) since late 1981. This product is available from 1981 to the present, with a one week time lag.”

    They provide a detailed description at the above link.

    Mike C: You wrote, “The IPCC’s cherry picking of start and end dates on the last graph is comprable to your cherry picking geographic locations.”

    There’s no cherry-picking on my part. The North Atlantic SST anomalies are impacted by a natural process known as Thermohaline Circulation and/or Meridional Overturning Circulation. Its effect is usually expressed as a residual, the Atlantic Multidecadal Oscillation, which is calculated as the difference between North Atlantic and Global SST anomalies. I simply illustrated the impact of this natural process on global SST anomaly trends by subtracting the North Atlantic SST anomalies from the Global SST anomalies. No cherry picking in that at all.

  8. Good analysis but the real question is “what is driving the North Atlantic SST”? It is showing a rate increase significantly larger than the Global rate increase. Why? Might it be undersea volcanic activity as we see along the rim of fire in the Pacific and along the western penisula of Anarctica? This may be a primary cause for a significant part of the Global warming during the past 100+ years. It brings us back to a time honored quite, figures don’t lie but liars can figure. If you parse a data set properly, you can distort the meaning to your point of view.

    Bill

  9. Hi Bob, another great post.
    I asked a question on Bill’s trade winds thread which got lost in the fast pace of the debate, but it seems more relevant to this post, so I’ll risk repeating it:

    I revisited a paper by Hathaway et al which compares solar activity, geomagnetic activity and the Armagh temperature record, which runs from 1840 in a non-uhi-contaminated location 65m above sea level near the coast of Ireland.
    http://solarscience.msfc.nasa.gov/papers/wilsorm/WilsonHathaway2006c.pdf

    At the top of page 8, there is a graph which shows the residual left after taking the sunspot numbers smoothed over the hale cycle from the temperature data smoothed over the hale cycle.

    Hathaway et al conclude with the usual “it could be AGW” statement at the end, but something caught my eye. If you were to subtract the AMO from the residual, you would end up with something pretty close to an anti-correlation.

    I realise the AMO will also have been affected by solar input, but given the AMO varies by 2C or so in the longer term, and the residual calculated by Hathaway et al is only 0.5C or so from peak to trough, it would seem that after allowing for the solar effect on the AMO and scaling it appropriatey before subtracting it from Hathaways residual there wouldn’t be much room for any accelerated co2 warming effect in the Armagh temperature record after the calcs were done.

    Would it be worth someone like yourself grabbing the data and doing a pro job on this?

  10. “Note that for shorter recent periods, the slope is greater, indicating accel­erated warming. …

    Accelerated warming, or merely warming? If the volcanoes had not exploded in the early 1980s, would this warming have happened in 1985 and then stopped at a slightly warmer level?

  11. I agree with lichanos, a GIS approach to to data selection would have been better for removing AMO locations.

  12. Mark Hugonson-

    Your comment was very helpful to me in the great quest of the ignorant (like me) to understand what all these statistics are about. I’m the kind of guy that likes to think about questions such as “what is a straight line.” Even Keeling’s data of atmospheric CO2 has enough of a bend in it to dub it the

  13. Hi Bob,

    You have left out 4 very significant eruptions and I am wonder why. Santa Maria 1902 VEI 6, New Britain 1905 Plinian, Ksudach 1907 VEI 5 and Novarupta 1912 VEI 6. Novarupta contained a huge amount of SO2. “At nearby Kodiak, for two days a person could not see a lantern held at arm’s length. Acid rain caused clothes to disintegrate on clotheslines in distant Vancouver, Canada.” http://vulcan.wr.usgs.gov/Volcanoes/Alaska/description_1912_eruption_novarupta.html

    Vancouver is 1400 miles away from Novarupta! They appear to show up on your graphs.

  14. Bob, You subtracted the ocean with the largest poleward heat transport. It’s analagous to Gavin subtracting an ocean with the smallest amount of heat transport and saying, “see, ocean circulation has nothing to do with increasing global temperatures.” That’s pretty much cherry picking.
    The greater the poleward heat transport, the greater the warming trend is expected to be regardless of the cause of the temperature change. Therefore, since you subtracted the ocean with the greater heat transport, you can now say the rest of the world is not really warming.
    Nor have you provided any evidence to back up your conclusion that the changes in the circulation are natural in origin. Since those currents are driven primarily by wind, you would have to show that the changes in atmospheric conditions were natural in origin.
    The better suggestion (for those with the wherewithall to do so) would be to calculate the expected heat content from downwelling IR which is absorbed, mixed and released by the oceans from increases in anthropogenic GHG’s. Then calculate the changes in heat content caused by solar. My understanding is that down welling IR only penetrates a few mm into the ocean where sunlight penetrates hundreds of feet.
    Your suggestion that volcanoes may be a possible cause has no merrit since you would need to show that volcanic activity has increased in only one ocean as oppoosed to others. Also, it would be easy to detect since we have a globally dispersed seismic system that would detect changes, both long and short term. Volcanic activity would also show up as plumes, particularly in the Atlantic where most activity is along the mid Atlantic ridge.

    • Mike C

      The whole concept of downwelling IR has a problem.

      IR absorption is shared with all the molecules of the local region making its energy available to the river of convection flowing upwards.

      IR emission is governed by the temperature of the emitting gas and the number of available emitters so the only way for IR absorption to increase IR emission is for it to raise the temperature of the emitting gas.

      Downwelling IR is like trying to walk down an up escalator pausing on each step as you go.

  15. Take Figure 7, break it at 1938, and flip the left hand side upside down.
    Again, break the graph at 1988 and flip the right hand side upside down.
    What you then have is the 1880-2009 version of my climate, which btw goes back to 1858 and has a sister-city to corroborate the area.
    We just don’t have the heat island effect here to screw up the data. We’re too darn far off the beaten path for that sort of monkey-business.

  16. Jim Powell: The Sato Index data should include the volcanoes you mentioned, as you noted. The bottom line was, there was no significant change in the trend of the long-term data with or without the volcanic aerosol data. Since there was little impact on the long-term trends I didn’t spend a lot of time describing the intricacies of the Sato Index dataset; that’s all.

    Regards.

  17. Mr. Tisdale:

    Gladly!

    I’m doing some traveling, it will be later in the week.

    But I’ll see if I can do some “stats” on this data.

    I just finished reading the Book, “Blink”. I highly recommend it. I just realized I have enough practice on statistics, and “SPC” that the graph you presented was SHOUTING to my “blink analyser” (that’s the subconcious) that, “Mark, Mark…MARK..there is something folks are missing here.” It may be that the statistical tests will show the data, for the amount of time we have observed, will fit a pattern of “random”. In which case we can postulate NO trend.

    Just as an aside, one of my “base training” realms was (is)
    Metallurgy. I’ve seen many a metallurgical data plot with 3 data points. Then “modeled” with: A. A straight line, B. A parabolic curve, C. A third order polynomial curve going precisely through all the points.. etc.

    Actually quite intertaining if you didn’t know that all three attempts at “curve fits” were really statistically bogus.

    Yours,

    Mark H. ( :-) /With a smile

  18. This may be a bit off topic but it seems to me that applying straight lines to data that obviously doesn’t follow straight lines is rather pointless. Take a quick look at the graph of earth’s temperature from the earlier article “CO2 does not drive glacial cycles”. When does the temperature follow a straight line? The answer would be almost never. The closest thing to a straight line would be the periods at the beginning of an interglacial warm period when the earth’s temperature shoots up as if it had been whacked by a hammer. Following those brief spikes, the temperature bounces up and down and gradually decays back to glacial conditions. But it very rarely follows a straight line, over any time span.

  19. During the ice age I graduated in Pure Mathematics.
    During this time I was told; “You cannot present calculations which are more accurate than the original measurements!!”

    Well now the ice age is over I am presented with ever more accurate calculations than even I would have dared to present.

    The First graph has a Linear Trend = ~0.0948 deg C/Decade
    An approximation, yes an approximation, correct to 5 decimal places.
    Those were accurate thermometers.

    I wonder what it might have been if the calculation was spot on and not just approximate?
    0.094799999999999999999999999999999999999
    0.094800000000000000000000000000000000001

    Me, I would have gone for approximately 0.1
    True 0.1 does not look as good; nor does it look really accurate.

    Second thoughts I’ll go for 0.09
    Yes! that is more impressive and far more accurate.

    What do think about 0.095?
    No, that does not do show accuracy, I’ll go for 0.09

    Second graph –> ~0.264
    Third graph –> ~0.0546
    Fourth graph –> 0.036 Yes exactly 0.036 spot on there!!
    Fifth graph –> ~0.040 A zero at the end. Now that is accurate. Zero!!!

    How are these values obtained?
    0.0948 requires all measurements of 0.0000xx(xx) deg C
    Are temperatures really measured to that accuracy?

    These values looks like implied accuracy to me.
    Impressive to look at.

    I wonder what Edward Lorenz would make of this new accuracy?
    He was not fooled.

  20. The North Atlantic Ocean (NA) is a strange beast. In this post, Bob T’s of 22/02/09, the NA is reported to have warmed. However, elsewhere I read that the Atlantic Meridional Overturning Circulation “has slowed by about 30 per cent between 1957 and 2004. Whereas the northward transport in the Gulf Stream across 25° N has remained nearly constant, …”

    http://www.nature.com/nature/journal/v438/n7068/abs/nature04385.html

    The geographic location reported on in this Nature article is 25o N. The SST data, if I’ve got it right, covers the NA with a 1o x1o resolution. The discrepancy in geography may negate trying to make a connection.

    My initial thought when reading the “circulation has slowed” was this would leave the high latitude NA cooler, not warmer. Or is it that the northern waters are exposed to solar input longer, by not sinking, and so warm?

    Then this, from the same Nature article: “In 2004, more of the northward Gulf Stream flow was recirculating back southward in the thermocline within the subtropical gyre, and less was returning southward at depth.”

    Does this mean the Gulf Stream water (less salty) became more entrained in the surface water of the NA causing warming? Less wind (weaker Westerlies) would slow the transfer of heat to the atmosphere. With less rapid cooling that water would stay near the surface longer.

    And from left field: Years ago I read that the warm-salty waters of the Mediterranean Sea exit at depth under in-flowing less-salty water from the Atlantic Ocean (~36o N.). That subsurface outflow will turn northward and be exposed as winds move the surface layer of the NA. I’ve no longer got the reference but the idea was that this Mediterranean Sea water contributed heat to the NA surface water closer to Europe than the Gulf Stream. The GS water seems to lose heat close to North America. See an image, page 3, on this NASA page:

    http://sealevel.jpl.nasa.gov/education/activities/ts2siac2.pdf

    Considering the volumes of these flows – Gulf Stream, sub-surface Mediterranean, and meridional circulation – slight variations in any could effect NA SST. So while all these data manipulations, graphs, trend lines, volcanoes, and anomalies make interesting (sometimes confusing) material I am still left with — The North Atlantic Ocean is a strange beast.

  21. Hi,

    If I read this correctly, you seem to indicate that removing the volcano impact reduces the warming. I thought that volcanos put aerosols in the air which reflects light and reduces temperature. If this was the case, then removing the volcano impact should increase temperature?

    Or have I got this completely wrong somewhere.

    I would appreciate a clarification.

    Shane

  22. 1880 to Jan 2009 is fine for comparison, but 2009 is just past the apex of the top of the warming cycle while 1880 was a few years before the apex. To get numbers that have more meaning, you would have to use the full 60 year ocean cycles. — John M Reynolds

  23. Oh, and if you use 1942 as the end point of the graph instead of 2002, you can just as easily show the accelerated warming of the 1930s. — John M Reynolds

  24. Apologies to my fellow readers for experimenting with tags and repeating a post that I already made.

    Mark Hugonson-

    Your comment was very helpful to me in the great quest of the ignorant (like me) to understand what all these statistics are about. I’m the kind of guy that likes to think about questions such as “what is a straight line.” Even Keeling’s data of atmospheric CO2 has enough of a bend in it to dub it the Keeling curve.

  25. Bill Yarber: You wrote, “…but the real question is ‘what is driving the North Atlantic SST’? It is showing a rate increase significantly larger than the Global rate increase. Why?”

    The answer to your question is “Thermohaline Circulation” and/or “Meridional Overturning Circulation”. There are numerous papers describing the process. Also refer to “Atlantic Multidecadal Oscillation”.

    tallbloke: I’ll take a look at your Hathaway paper in a few days.
    deadwood: You wrote, “I agree with lichanos, a GIS approach to to data selection would have been better for removing AMO locations.”
    If you’re speaking from experience with the data presented from the NOMADS system, please present how a GIS approach would have provided a better presentation of the data. I’m always looking for different or better way to do things. Thanks.
    Mike C: You’re over analyzing a simple post. You wrote, “Therefore, since you subtracted the ocean with the greater heat transport, you can now say the rest of the world is not really warming.”
    All I did was note the difference in the trends and the impact of the Atlantic on those trends. I never said anything beyond that.
    You wrote, “Nor have you provided any evidence to back up your conclusion that the changes in the circulation are natural in origin.”
    My use of the term natural with respect to the cyclical variability is based on the paleoclimatological record for North Atlantic SST anomalies. Refer to Gray, S.T., et al.. 2004, “Atlantic Multidecadal Oscillation (AMO) Index Reconstruction.”
    ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/amo-gray2004.txt
    A graph of the data:

    I’ll agree that I have presented no proof that the present variations are natural in origin, but the cycles existed prior to the industrial age, and present North Atlantic SST anomalies are not outside the range of the paleoclimatological record.

    My sentence would probably have been better written as, “Had the North Atlantic SST anomalies not been rising as part of the Atlantic Mutlidecadal Oscillation…”, and “Had the North Atlantic not been on the upward portion of that cycle, it is likely that the global SST anomalies would not have risen as high,” or something to that effect.

    You wrote, “Your suggestion that volcanoes may be a possible cause has no merrit since you would need to show that volcanic activity has increased in only one ocean as oppoosed to others. Also, it would be easy to detect since we have a globally dispersed seismic system that would detect changes, both long and short term. Volcanic activity would also show up as plumes, particularly in the Atlantic where most activity is along the mid Atlantic ridge.”

    I didn’t state or imply that volcanic activity has “increased in only one ocean as opposed to the others”. I subtracted a global aerosol optical thickness dataset that appeared to be scaled correctly for my purposes from a global SST anomaly dataset. Would you have preferred it if I had removed the effects of the volcanic aerosols prior to subtracting the Atlantic SST anomalies from the global SST anomalies? It would make no difference to the trends.

    You wrote, “The better suggestion (for those with the wherewithall to do so) would be to calculate the expected heat content from downwelling IR which is absorbed, mixed and released by the oceans from increases in anthropogenic GHG’s. Then calculate the changes in heat content caused by solar. My understanding is that down welling IR only penetrates a few mm into the ocean where sunlight penetrates hundreds of feet.”

    If YOU have the wherewithal, please feel free to do so. Also, don’t forget to include the changes in downward infrared caused by variations in water vapor, or the changes in downward shortwave radiation due to cloud cover variations, or the changes in IR absorbed in the ocean mixing layer caused by variations in wind speed and wave action. Don’t forget the step changes in North Atlantic SST anomalies caused by the El Nino events of 1986/87/88 and 1997/98 or the changes in AMOC volume due to ENSO events. And please make sure to weight everything correctly so that your assumption that GHGs have a noticeable influence on the North Atlantic temperature doesn’t influence the outcome.

    Again, you’re overanalyzing a simple post.

    Robert Bateman: You wrote, “We just don’t have the heat island effect here to screw up the data. We’re too darn far off the beaten path for that sort of monkey-business.”

    The data presented is sea surface temperature, not land surface temperature.

    David Segesta: You wrote, “This may be a bit off topic but it seems to me that applying straight lines to data that obviously doesn’t follow straight lines is rather pointless.”

    It’s not off topic. The trend lines simply show a rate of change in the data. As illustrated, the IPCC uses trend lines to illustrate accelerating global temperatures. I illustrated that the majority of the global SST anomaly trend from Nov 1981 to January 2009 comes from the North Atlantic. Had the North Atlantic not been on the upward portion of the Atlantic Multidecadal Oscillation cycle, the global temperature anomalies likely would not have accelerated as shown by the IPCC…or accelerated as much.

    Shane: You wrote, “If I read this correctly, you seem to indicate that removing the volcano impact reduces the warming.”

    In the short-term data, the volcanic eruption occurred in the early years. This pulled the temperatures down, thereby increasing the trend. Taking the effects of the volcanic aerosols out of the short-term data would therefore increase the temperature in the early years and decrease the trend.

    jmrSudbury: You wrote, “1880 to Jan 2009 is fine for comparison, but 2009 is just past the apex of the top of the warming cycle while 1880 was a few years before the apex. To get numbers that have more meaning, you would have to use the full 60 year ocean cycles, “ and “Oh, and if you use 1942 as the end point of the graph instead of 2002, you can just as easily show the accelerated warming of the 1930s.”

    I used the entire datasets available for the OI.v2 SST and ERSST.v2 data. And I deleted the early years of the HADISST data so that it had the same time span as the ERSST.v2 data. Based on its intent of this post, I saw no reason to abridge the datasets.

  26. B Kerr

    I recall very well my high school physics classes. One of the first things we learned about was significant figures. I even recall a conversation in the hallway with fellow students about sig figs. I believe the point of significant figures is the exact on that you are making. It would be nice to see in a future article what some of these weather instruments look like up close. I am imagining glass thermometers that people have to bend over and squint at to read properly. I also believe I heard that in the extremes of Norway mercury thermometers fail because of the high solidifying point of mercury (something like minus forty, I suppose). Is there such a thing as a standard thermometer or barometer? …. and hasn’t the issue of significant figures been examined in depth and to great subtlety by experimental physicists? I can’t imagine there really is such a thing as a global average temperate that is better than x “give or take a degree”

  27. Something I have wondered about is what happens in the atmosphere when the sea levels drop some 400 feet as they did during the last ice age. There are many volcanoes that under water but within 400 feet of the surface. Rather than dumping their ash and and sulphur dioxide into the ocean, it would be injected into the atmosphere. I wonder if this is another item that tends to keep further cool the planet once it begins to cool.

    So sea levels begin to drop, more volcanoes emerge from the sea, more ash and SO2 is injected into the atmosphere resulting in more cooling, sea levels drop even more exposing more volcanic vents, etc.

  28. Bob Tisdale

    Gray, S.T., et al.. 2004, “Atlantic Multidecadal Oscillation (AMO) Index Reconstruction.”
    ftp://ftp.ncdc.noaa.gov/pub/data/paleo/treering/reconstructions/amo-gray2004.txt
    A graph of the data:
    http://i36.tinypic.com/wld5kl.jpg

    Bob, I’m really pleased you think my idea is worth a look. The above link you provided to the long term reconstruction is interesting. Of course, sunspot data goes back a long way too, so you could extend the Hathaway data, perhaps looking at the CET for earlier temps in addition to the Armagh record, if you can get a copy of the CET data off Hadley. They seem to restrict it’s access.

    One observation. the reconstruction you link shows the AMO in a negative phase from 1690-1730, yet CET shot up over 3C in the same time frame. Whats up with that?

  29. Crosspatch, a lot of weight and coolness would come off the volcanoes too, making them more likely to erupt. Plus all the histerisis (sp?) involved and the surface changing shape. Seems like you are onto a good positive feedback theory there.

  30. Bob, Like I pointed out in my first comment to your post, the IPCC cherry picks timeframes. That is the only way they can come to the conclusion that global temps have accelerated. Specifically, all of their timeframes end at the same time, which is at the end of a warm period.

    As for volcanoes affecting different oceans differently, in a comment to Bill Illis’ previous post (right about the time I made about the same point), you discussed how different volcanoes affect global temps differently (I believe that you were discussing the latitude of Novarupta). I believe we also discussed El Chichon where the cooling effects are primarily seen in the northern hemisphere. How can you now come back and say the opposite? The ocean in question here is the NORTH Atlantic, is it not? Do you see the similarity? North… latitude. Krakatoa isn’t even in the same hemisphere as Pinatubo. They are both in different atmospheric zones, not to mention that the two eruptions occurred in different seasons, which would lead to a different displacement of the initial aerosol streams due to the N-S drift of the ITCZ. So yes, in order to make any estimate of how the volcanoes affected the trends, you would need all of the different data applied correctly, specifically how the different eruptions affected different oceans.

    As for the wherewithal comment and your assertion that I believe that GHG’s have “a noticeable influence on North Atlantic temperature,” you are way off the mark. Your comment suggests that I was leaving the impetus on you to do the calculations. I was not. Please note my use of the word “anyone.” We already have significant evidence from the Campos paper that changes in global temps originate in the oceans, specifically SST’s. We also have significant evidence that increases in Anthropogenic GHG’s cause a specific increase in down welling IR. And from the solar perspective, we have good measurements by Peter Foukal on luminosity changes (although he seems to have failed at distinguishing luminosity and TSI in his 06 paper) that can give us an idea of what solar has given us over time. There would be margins of error, but ANYONE reading, preferably with Physics degree and the ability to retrieve and process the data, you could possibly answer the great question of the day… does man influence global temperatures by releasing GHG’s.

    • Mike C: The discussion a few days ago about volcanic aerosols on another thread had to do with whether they should be included in the model (I believe I agreed with you that yes, they should) and why they did not have a noticeable impact on early global temperature anomalies. I pointed out that the reason the early eruptions did not appear to have a significant effect could have been the latitude of the eruption and how sparse the data was in the late 1800s, early 1900s.

      With respect to this post, as I noted in an earlier comment to another blogger, this was a simple post, intended to illustrate a few points about the short-term trends:
      -That the North Atlantic was the dataset with the highest recent linear trend,
      -That the North Atlantic has a significant impact on Global SST anomaly linear trend,
      -That the Volcanic eruptions of El Chichon and Mount Pinatubo also impact the linear trend, and
      -That the IPCC, who also use short-term trends, by failing to account for the natural variability of the North Atlantic and the effects of volcanic aerosols, exaggerate their claims of accelerated warming due to anthropogenic forcings.

      Could I have use hemispheric Sato Index data to refine the changes in trend? Yes. Would that have altered the outcome of the points above? No. It would only have changed the hemispheric distribution of volcanic aerosols, altering the values of the trends, but, bottom line, the SSTs in and around 1982 and 1991 would have risen with the adjustments and the short-term trends would have decreased. The same point would have been made with twice the work.

      As to long-term trends, I noted in the post and in my replies to other bloggers that the volcanic aerosols had little effect on the long-term trends. Again, could I have used hemispheric Sato Index data to refine the long-term trends on a hemispheric basis? Yes, but since there was little difference in the trends whether I included or excluded the volcanic aerosol adjustments, why bother?

      I’m not saying that the volcanic eruptions did not cause short-term changes in global temperatures; I’m saying that there was little effect on long-term trends.

      With respect to my wherewithal reply, I was responding to your use of the word wherewithal. I also did not believe that you were placing the impetus on me to do the follow-up work, but I did note that numerous other factors need to be taken into consideration.

  31. A very interesting subject, and also interesting data; which I am just going to take at face value; having no means nor any reason or incentive to not do that.

    But it did trigger a response in me. Some time ago, I Googled “climate”, and maybe it took me to Wikipedia, and a few other places; and all of them said pretty much the same thing.

    “Climate” is (by definition) ; “The long term average of “weather”.

    I don’t recall that it said what “long term” means; but if climate is the long term average of weather, and if “term” generally means both time wise and space wise; so that climate is the long term average over time, and space on planet earth; then why is the climate not specified by a single number; well at least for that facet of climate that is the mean global surface or lower troposheric temperature; or even the GISStemp anomaly.

    So why do climatologist plot daily, monthly even annually “anomalies” or mean global temperatures, when they continue to tell us that even a year isn’t climate, so the dramatic anomaly drop from Jan 2007 to jan 2008 in GISStemp anomalie, and also the other three popular measures clearly was a weather phenomenon, and not a climate phenomenon.

    So how come Dr James Hansen doesn’t simply reort a single number that truly is the long term average of the GISStemp anomaly; that quantity being the output of Anthony’s array of missguided Owl boxes, that pass for the data input to Hansen’s famous AlGorythm.

    So Just give us the number Jim, and forget all this short term weather stuff, which is just confusing people and leading them to believe something is happening; when really nothing much is happening at all; well not to the climate anyway.

    Well what is one to say about a “Science” that can’t even properly identiry what it itself even is.

    It is quite clear to me that one thing that “the climate” most assuredly is NOT; is the “long term average of weather”.

    I would suggest; and have several times before; that: CLIMATE IS THE INTEGRAL OF WEATHER.

    Whateve happened between Jan1 2007, and Jan 1 2008; assuming of course that what we saw was in fact real data, and not just noise masquerading as a data signal; whatever happened next after Jan1 2008, started with what the climate was on Jan 1 2008, and whatever happens tomorrow is going to start from wherever the blazes the climate is today; the average is a totally meaningless quantity; it wasn’t observed or measured anywhere on planet earth at any time.

    So all those pretty graphs up above; are they climate or are they simply weather; enquiring minds want to know.

    George

    • “Climate” is (by definition) ; “The long term average of “weather”.

      I don’t recall that it said what “long term” means; but if climate is the long term average of weather, and if “term” generally means both time wise and space wise; so that climate is the long term average over time, and space on planet earth; then why is the climate not specified by a single number; well at least for that facet of climate that is the mean global surface or lower troposheric temperature; or even the GISStemp anomaly.

      I see where you are coming from, but I think the earth has many localised climates, and they are the integral of local weather.

      E.g. Britain has a ‘maritime climate’, which is why our weather here doesn’t swing to such extremes as the nearby continent. Climate is localised by other factors apart from temperature, precipitation for example. We get hung up on temperature, but there is more going on besides which determines climate.

  32. Hank:
    “… I also believe I heard that in the extremes of Norway mercury thermometers fail because of the high solidifying point of mercury (something like minus forty, I suppose). …”

    Yes, and that might set a lower limit on some records. But that characteristic was known at least by the early 1900s. (“It was due to a misunderstanding that mercury thermometers
    were not also used in the first half-year, during those periods when
    the temperature did not go below the freezing-point of mercury
    (-39°C.).” — “The South pole; an account of the Norwegian Antarctic expedition in the “Fram,” 1910-1912″)

  33. crosspatch (16:40:53) :

    Most of the submarine volcanic action you refer to is basaltic – i.e. mostly non-explosive (think Kilauea, Hawaii). These don’t produce much ash (although they do emit lots of gases). The big blasters are andesitic to rhyolitic volcanoes – those producing much more viscous, silica-laden lavas.

    When the pressure is taken off magma chambers filled with the former kind, it just flows out, with maybe a nice local fireworks display. With the latter kind of magma, it blows up, creating the Pelean to Plinian (type names) eruptions that blast huge columns of ash outward or miles into the atmosphere.

  34. “Bob, You subtracted the ocean with the largest poleward heat transport. It’s analagous to Gavin subtracting an ocean with the smallest amount of heat transport and saying, “see, ocean circulation has nothing to do with increasing global temperatures.” That’s pretty much cherry picking.”

    Cherry picking is when you selectively choose data to prove a point and you don’t tell anyone. When you remove a subset of data and tell everyone that you are doing that to isolate the effect on SST that’s analysis.

  35. Folks,

    The issue of weather and climate definitions comes up because these terms were needed years ago for people interested in, or being sent off to, far off lands. Think of a country’s foreign service officers. They needed to know whether to take sheepskin boots or sandals, and so on. Weather data over time was collected and the patterns noted. Such things as warm, cool, or cold winters; or dry and hot summers, or moist wet summers. The described patterns of seasonal temps, rain, snow, dryness and so on became coded. The head officer could say, “Bruce, you are going to a Csa climate, pack accordingly.” WIKIPEDIA has a decent example* of this sort of coding with a nicely colored map. This isn’t the only such scheme. In any case, the climate of a place is a pattern that is being described, not an average. It does no good to worry about the oddness of a definition in the “global climate” change context when the dictionary definition terms were created in a earlier era.
    *http://en.wikipedia.org/wiki/K%C3%B6ppen_climate_classification

    • Brad, as you are aware, ocean heat content is an entirely different variable, so it does not influence this post on SST. And right now, OHC data is a work in progress. The entire dataset varies from year to year and month to month with adjustments and corrections that impact the it from year one. Five to ten years from now, they may sort it out.

      • The good thing about glaciers and icecaps is that they are long-term climate integrators, so changes in their rates of melting will be slow. Also, it is hard for major changes in ice volume to occur over long time frames without being measurable. We should see thinner icesheets, retreating glaciers, etc.

        There are, as you know, gravity and other measurements of ice volume.

        Besides, OHC increases and ice volume losses should be pretty well correlates, wouldn’t you agree? Since bothe are a function of global warming?

  36. Anthony, you say that e; niños are driving the North Atlantic trend, yet a metric for ENSO such as SOI shows almost no trend over this period – certainly not enough to account for the large trend in temperature in that area.

    Wouldn’t it be more accurate to simply remove the effects of el niño using such a metric as SOI (for example) as there can be other factors in the North Atlantic warming, *may* be actually to do wil AGW (for all we know).

    • “*may* be actually to do wil AGW (for all we know).”

      Even though oscillations in the AMO of equally large amplitude have happened before industrialisation? Are you aware it just turned negative again?

      BTW, Bob Tisdale made the post, not Anthony.

    • Alex: I wrote this post.

      You wrote, “…you say that e; niños are driving the North Atlantic trend…”

      I wrote, “The North Atlantic linear trend is approximately 2.8 times the global linear trend, driven by Atlantic Meridional Overturning Circulation and El Ninos, (yes, El Ninos).”

      El Ninos are a factor, but not the only thing driving North Atlantic SST anomalies.

      Refer to my post “There Are Also El Nino-Induced Step Changes in the North Atlantic”. Link:
      http://bobtisdale.blogspot.com/2009/02/there-are-also-el-nino-induced-step.html

      Those step changes illustrate that the North Atlantic SST anomalies responded to the 1986/87/88 and 1997/98 El Nino events but did not react in the same way to the subsequent La Nina events. SSTs rose as a result of the El Ninos, but did not drop with the La Nina. El Nino events and La Nina events are not the same. The step changes need to be accounted for when removing the effects of ENSO.

  37. “Do you think global ocean heat content increasing at an accelerating rate over the last few decades is a problem for your thesis?”

    Heat content can not be increasing if the ocean temperatures are falling. Also, sea levels have been steady to falling overall since 2006. The rather linear rise in sea levels over the past 30 or so years stopped in 2006.

    If you look at this graph and cover the portion earlier than the second half of 2005 with your hand, you will see that the rising trend stopped and the trend is flat over the past 4 years. This is unprecedented over the duration of satellite sea level measurements and the Argos sea temperature project has shown a slight cooling of the ocean from the surface down to about 2000 meters, I believe.

    There is no warming of the ocean so there is no increase in heat content. On the contrary, the ocean is cooling and not just at the surface.

    • Hey Crosspatch, get with the plan and use the ‘reply’ link at the bottom of the post you want to comment on. :-)

      “It’s acceleration Jim, but not as… hey! Who slammed the brakes on?” :-)

    • “If you look at this graph and cover the portion earlier than the second half of 2005 with your hand, you will see that the rising trend stopped and the trend is flat over the past 4 years. ”

      If you download the data from the Univ of Colorado website, apply a linear trend for the time period you mentioned, you will see that your eye is not very good at discerning trends. Its about +1.4mm/yr from 2005.5 to 2008.98. Not flat at all, and similar to all previous transitions from El Nino to La Nina.

      If you follow such small trend changes over short time intervals, you will be running for the hills, screaming about the 2nd coming of the Great Flood, next time we have an El Nino that temporarily bumps up the SL increase trend.

      Your info about the Argo data is out of date. Ocean heat content is rising, according to the latest measurements. See the graph halfway down here:

      http://www.cmar.csiro.au/sealevel/sl_drives_longer.html

      Bottom line, SL is increasing at 3.3mm/yr for 15 years, and the latest data are right on that trend line.
      OHC, as of the last data point in 2007, was rising at the fastest rate ever for the same 15 year period.

      • The two data sets look identical to me, except for some noise. Possible due to different measurement depths, as you point out. Both show an increase of about 15*10^22 joules over the past 20 years. There is a one-year decrease on your link not present on my link. It seemes to have occurred, like the other one-year decreases, at a transition from El Nino to La Nina. It also lines up with the slow down in the rate of SL increase that occurred around that time (and ended in late 2008), and the strong decrease in satellite temps (that ended in mid 2008).

        Again, like Crosspatch, you are focusing on short term noise, at least when it is going in the direction you favor. Since we have more up-to-date SL data showing a rebound (through the end of 2008), and we know that satellite temps have spiked up in the past few months (we have daily data through yesterday at AMSU), wouldn’t you agree it is likely that OHC is currently going up again?

        Can you also agree that the 15 year trend is strongly up for OHC and SL? Does the latest decrease in OHC data reverse this trend, or even fall below it?

        Your original post closed with a comment about long term trends of global SST, and extrapolated that trend for 100 years. I was trying to compare that to other long term global data series, like OHC and SL, which are going up at unprecendented rates. But now you prefer to look at 1 or 2 years of noisy data at the end of that long up-trend?

        Maybe this time is different. THIS one or two year decrease in OHC will be the turning point that reverses 30 years of warming. Show me why.

  38. I was looking at how the bluestones at StoneHenge were dated via Cl36… and that got me thinking (always a dangerous thing!)

    From the wiki: http://en.wikipedia.org/wiki/Chlorine-36

    “36Cl is produced in the atmosphere by spallation of 36Ar by interactions with cosmic ray protons. ”

    OK, so we have Cl in the air proportional to Ar and Cosmic Rays. And we know that Cl in the upper air is antagonistic to ozone. And we know that ozone is important to blocking the 9-10 micron IR band…

    So my speculation would be this:

    1) Where does the Ar come from? Is it proportional to volcanic emissions in any way? Can the historic quantity of Ar in the atmosphere be correlated with climate changes? Is Ar proportional to some other driver (solar or???) or is it more or less a constant over 10,000 year horizons?

    2) Shades of Svensmark: GCR modulation would potentially modulate clouds up and ozone down giving two drivers of climate modulation when the solar mag field goes low. Or perhaps this is just demonstrating the mechanism for the already observed fact that GCRs deplete ozone?

    Strange where lines of investigation lead you… from 10,000 year old stones to future climate changes from galactic cosmic rays…

  39. BOB TISDALE
    Based on the smoothed data curve of the HADCRUT3 global air temperature graph [per http://www.cru.uea.ac.uk/cru/info/warming/%5D the temperature increased 0.465 degrees C between 1910 and 1940. This is almost the same as the so ‘called manmade global warming’ period increase of 1976-2007 or 0.491 degrees C. So the claim that the unprecedented warming during the period 1976-2007 could only have been caused by the sudden increase in manmade greenhouse gas emissions levels after 1976 seems false since similar warming have occurred before and this one quite recently when manmade CO2 levels were low .
    CO2 could not have been the reason for global warming periods prior to 1945 because the CO2 levels did not increase significantly until after the mid 1940’s.

    I come back to the IPCC statement,namely
    Results from climate models driven by estimated radiative forcings for the 20th century (Chapter 9) suggest that there was little change prior to about 1915, and that a substantial fraction of the early 20th-century change was contributed by naturally oc¬curring influences including solar radiation changes, volcanism and natural variability. From about 1940 to 1970 the increasing industrialisation following World War II increased pollution in the Northern Hemisphere, contributing to cooling, and increases in carbon dioxide and other greenhouse gases dominate the observed warming after the mid-1970s.”

    One of the key points that I have been making is that the so called global warming from mid 1976 to 2007 is due to the near simultaneous occurrence of the POSITVE[WARMING ] AMO AND THE POSITIVE [WARMING] OF ENSO/PDO especially 1995-2007 .

    Could you compare the these two periods ie 1910 to 1940[especially1925-1945 with the period 1976 -2007[ especially 1945-2007] to see if the oceans were acting about the same in terms of warming.

  40. MattV:

    The disparity in the trends between the early rise versus the latter rise is so great, there’s no reason to throw trend lines on them. Here are the three long-term SST datasets. Other than the smoothing, I haven’t made any adjustments to them.

    HADSST version:

    ERSST.v3 version:

    ERSST.v2 version:

    Note that the rate of rise in the early 20th century warming period far exceeds that of the last 30 years or so. But the anthropogenic greenhouse gases impact on SST, according to some, should be much more dominant in the last 30 years. I don’t see it. The El Nino around 1940 was significant but not as large as the 1997/98 El Nino, so that shouldn’t be throwing off the trend of the early warming period.

  41. Brad Beeson: Anthony turned off the nesting so it’s hard to tell if your two most recent comments are directed to me. If they are, my earlier comment about the OHC data being a work-in-progress still applies. Five to ten years from now, maybe they’ll have it sorted out. Maybe not. It took decades for TSI to get to the level it’s at today. They’ve only just started reconstructing OHC.

  42. BOB TISDALE

    Very nice work , Bob. You just confimed with your excellent SST GRAPHS the point that I was making earlier . namely that the IPCC statement that……

    “From about 1940 to 1970 the increasing industrialisation following World War II increased pollution in the Northern Hemisphere, contributing to cooling, and increases in carbon dioxide and other greenhouse gases dominate the observed warming after the mid-1970s.”

    is basicaly flawed. A Similar warming took place 1910-1940 when the co2 was not a factor. Thus warmings due to natural causes like ocean cycles that took place between 1976-2007 can and have happen quite recently [1910 -1940] and this is a much more plausible and measurable reason for the warming than the minor increase in CO2 levels . With both the global SST anomalies and global air temperature anomalies confirming the argument, there is strong case to be made here. What do you think?

  43. tallbloke: I just took a look at Figure 5 (page 8) from the Wilson Hathaway paper. I printed that page and wrote in the years each of the sunspot cycles peaked, then visually compared Figure 5 to the AMO graph you posted. Your AMO graph starts in 1880, which is just before the peak of SC12, so block off all the data before SC12 on Figure 5. The apparent correlations between the residuals and the AMO disappeared once I did that.

    Regards

  44. Matt V: And to add to your argument, what caused global SST anomalies to drop so significantly from the late 1800s to 1910, then rebound? Refer to:

    http://bobtisdale.blogspot.com/2008/11/dip-and-rebound.html

    and:

    http://bobtisdale.blogspot.com/2008/12/dip-and-rebound-part-2.html

    Note how well the shape of the “dip and rebound” fits with the ~1975 to ~2000 rise in SST. I had never used the phrase “within the range of natural variability” until that post.

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