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
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.
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
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.
The IPCC’s cherry picking of start and end dates on the last graph is comprable to your cherry picking geographic locations.
Anthony: That was quick. Thanks.
I aim to please when a good essay is involved –
Anthony
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
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.
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.
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
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.
http://images.intellicast.com/App_Images/Article/129_0.png
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?
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?
I agree with lichanos, a GIS approach to to data selection would have been better for removing AMO locations.
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
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.
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.
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.
AEROSOLS!
I read it wrong at first.
Sorry…
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.
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
Mark: In case you’ve never visited her website, Lucia at “The Blackboard” has done a lot of statistical analyses of global temperature anomaly data.
http://rankexploits.com/musings/
SST data isn’t as noisy as global land + sea surface temp, but her findings might help with your investigation.
Regards
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.
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.
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.
Sorry, I guess the degree symbol doesn’t make it through the transfer!
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
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