Does The Sea Surface Temperature Record Support The Hypothesis Of Anthropogenic Global Warming?
Guest post by Bob Tisdale
This post is an expansion on my earlier post Sea Surface Temperature Anomalies – East Pacific Versus The Rest Of The World. In that post, I broke the satellite-era Sea Surface Temperature (SST) anomaly data for the global oceans into two subsets. The volcano-adjusted East Pacific SST anomaly data (90S-90N, 180-80W) shows no rise for the past 30 years and the SST anomalies for the Rest-Of-The-World (90S-90N, 80W-180) rose in two easily discernable steps. I used period average SST anomalies to highlight the steps.
This post is also similar in content to the post How Can Things So Obvious Be Overlooked By The Climate Science Community? But in this one, I provided a better way to divide the decade-plus periods that run from the end of the 1986/87/88 El Niño to the beginning of the 1997/98 El Niño and from end of the 1997/98 El Nino to the beginning of the 2009/10 El Niño. This allows for a more consistent way to illustrate the actual Rest-Of-The-World SST anomaly trends between those significant ENSO events.
THE ONE-WORD ANSWER TO THE TITLE QUESTION IS NO.
The satellite-era Sea Surface Temperature record indicates they rose only in response to significant El Niño events. In other words, the Sea Surface Temperature data contradicts the IPCC hypothesis that most of the rise is caused by an increase in Anthropogenic Greenhouse Gases.
The fact that the satellite-era SST anomalies do not support AGW is very easy to illustrate with two graphs, Figure 1. They show the satellite-based sea surface temperature (SST) anomalies for two subsets of the global oceans, using Reynolds OI.v2 SST data that runs from November 1981 (the start of that dataset) to the current month of May 2011. The graph on the left illustrates the volcano-adjusted Sea Surface Temperature for the eastern Pacific from pole to pole (90S-90N, 180-80W). That area represents about 33% of the global ocean surface area. There are major variations from year to year caused by El Niño and La Niña events, but the linear trend is basically flat at +0.003 deg C per decade. In other words, there has been no rise in the volcano-adjusted Sea Surface Temperatures for that portion of the global oceans in almost 30 years. The graph on the right illustrates the volcano-adjusted SST anomalies for the rest of the world from pole to pole (90S-90N, 80E-180). The SST anomalies for this portion of the globe show two distinct upward steps with periods of relatively little (if any) rise between those steps. The upward steps are highlighted by the average SST anomalies for the periods between the upward shifts caused by El Niño-Southern Oscillation events. There is an upward step in 1987 that occurs in response to the 1986/87/88 El Niño, and there is an upward step in 1997, which is a response to the 1997/98 El Niño. Note how the Rest-Of-The-World SST data appears to be in the process of another upward step in response to the 2009/10 El Niño.
Figure 1
Figures 2 and 3 are full-sized versions of the volcano-adjusted East Pacific and Rest-Of-The-World SST anomaly graphs. These datasets were first discussed in my post Sea Surface Temperature Anomalies – East Pacific Versus The Rest Of The World, and they have appeared in my monthly SST anomaly updates since then. Two notes: The Sea Surface Temperature dataset used in this post is NOAA Optimum Interpolation, version 2 SST, also known as Reynolds OI.v2. And as noted during the discussion of Figure 1, both subsets have been adjusted for the effects of the explosive volcanic eruptions of El Chichon in 1982 and Mount Pinatubo in 1991. I performed a linear regression analysis on global SST anomalies to account for the impacts of the volcanic aerosols. This was discussed in the post linked above.
Figure 2
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Figure 3
THE REST-OF-THE-WORLD SST ANOMALY TRENDS BETWEEN THE SIGNIFICANT EL NIÑO EVENTS
Above I described the Rest-Of-The-World SST data as having two distinct upward steps with periods of relatively little (if any) rise between those steps. Actually, the linear trend for the period between the El Niño events of 1986/87/88 and 1997/98 is -0.01 deg C per decade and for the period between the El Niño events of 1997/98 and 2009/10 it’s +0.001 deg C per decade. Refer to Figure 4. In other words, the volcano-adjusted Rest-Of-The-World Sea Surface Temperature anomalies rose in response the significant El Niño events of 1986/87/88 and 1997/98, and then the sea surface temperatures did not rise over the decade (plus) periods that followed.
Figure 4
To establish the periods between the significant El Niño events, I used the NOAA Oceanic Nino Index(ONI) to determine the official months of the 1986/87/88, 1998/98, and 2009/10 El Niño events.. There is a 6-month lag between NINO3.4 SST anomalies and the response of the Rest-Of-The-World SST anomalies during the evolution phase of the 1997/98 El Niño. So I lagged the ONI data by six months and deleted all of the Rest-Of-The-World SST data that corresponded to the El Niño events of the 1986/87/88, 1998/98, and 2009/10 El Niño events. Then I performed the trend analyses on the data for the two periods that remained.
There will be those who will attempt to downplay the trend analyses shown in Figures 4 by stating that I’ve excluded the data after June 2009 to hide a rise in SST anomalies. In reality, I’ve excluded that recent data because the 2009/10 El Niño appears to be causing yet another upward step as shown in Figure 3.
CLOSING
Unless Anthropogenic Greenhouse Gases only impacted Sea Surface Temperature Anomalies during the 1986/87/88 and 1997/98 El Niño events, there is no evidence of Anthropogenic Global Warming in the satellite-era Sea Surface Temperature data. The volcano-adjusted East Pacific Ocean Sea Surface Temperature anomalies have not risen in 30 years. For the Rest Of The World, the volcano-adjusted Sea Surface Temperature anomalies rose only during the El Niño events of 1986/87/88 and 1997/98, but between the 1986/87/88 and 1997/98 El Niño events and between the 1997/98 and 2009/10 El Niño events, there was no rise in the volcano-adjusted Rest-Of-The-World Sea Surface Temperatures.
I have presented and described ENSO and the multiyear aftereffects of ENSO in numerous posts over the past years. Links to many of them are listed under the heading of FURTHER INFORMATION.
ENSO is a process that periodically discharges heat from the oceans and redistributes warm waters from the tropical Pacific. ENSO also recharges the tropical Pacific Ocean Heat through a periodic increase in Downward Shortwave Radiation. In that respect, ENSO events are fueled by a periodic increase in natural radiative forcing (solar energy) over the tropical Pacific. When El Niño events dominate a multidecadal era, indicating the tropical Pacific is releasing and distributing more ocean heat than “normal”, global surface temperatures rise. The opposite holds true during epochs when La Niña events dominate.
SOURCES
SST anomaly data is available through the NOAA NOMADS website:
http://nomad1.ncep.noaa.gov/cgi-bin/pdisp_sst.sh
or:
http://nomad3.ncep.noaa.gov/cgi-bin/pdisp_sst.sh?lite
The GISS Global Stratospheric Aerosol Optical Thickness data is available here:
http://data.giss.nasa.gov/modelforce/strataer/tau_line.txt
FURTHER INFORMATION
My first detailed posts on the multiyear aftereffects of ENSO events are:
Can El Nino Events Explain All of the Global Warming Since 1976? – Part 1
And:
Can El Nino Events Explain All of the Global Warming Since 1976? – Part 2
And:
Supplement To “Can El Nino Events Explain All Of The Warming Since 1976?”
And:
Supplement 2 To “Can El Nino Events Explain All Of The Warming Since 1976?”
And for those who like visual aids, refer to the two videos included in:
La Niña Is Not The Opposite Of El Niño – The Videos.
The impacts of these El Nino events on the North Atlantic are discussed in:
There Are Also El Nino-Induced Step Changes In The North Atlantic
And:
Atlantic Meridional Overturning Circulation Data
I’ve also written a rebuttal post to Tamino’s AMO Post. I hope to have a new post on the North Atlantic posted sometime soon.
The posts related to the effects of ENSO on Ocean Heat Content are here:
ENSO Dominates NODC Ocean Heat Content (0-700 Meters) Data
And:
North Atlantic Ocean Heat Content (0-700 Meters) Is Governed By Natural Variables
Additional detailed technical discussions can be found here:
More Detail On The Multiyear Aftereffects Of ENSO – Part 1 – El Nino Events Warm The Oceans
And:
More Detail On The Multiyear Aftereffects Of ENSO – Part 2 – La Nina Events Recharge The Heat Released By El Nino Events AND…During Major Traditional ENSO Events, Warm Water Is Redistributed Via Ocean Currents.
And:
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Bob, have you looked at how they tune the SST satellites?
When they do something “unexpected”, look at what they consider expected, and where that came from. SST’s staying the same or going down is “unexpected”, and obviously wrong. So they get re-tuned again……………
But you will always be wrong,,,,,,,from Mr AGW
What is the time lag between ocean heat content changes due to the solar variability and the subsequent re-distribution of energy through the ENSO events, and the then measured impact on global air temperatures ?
With whats happening in Australia, sites like these will have to take a much much tougher stance. WE are not way enough taking these guys on. If you don’t you will end up like Australia. The legal eagles need to start acting NOW
ImranCan says: “What is the time lag between ocean heat content changes due to the solar variability and the subsequent re-distribution of energy through the ENSO events, and the then measured impact on global air temperatures ?”
I’ve never seen it your question addressed in a paper. An incease in Downward Shortwave Radiation from a La Nina event provides the fuel for the next El Nino. Example: Due to unusually strong trade winds over the western tropical Pacific, the 1995/96 La Nina provided a substantial increase in tropical Pacific OHC.
http://i56.tinypic.com/a5dhy0.jpg
That inreased in Tropical Pacific OHC fueled the 1997/98 “El Nino of the Century.” So the lag was less than two years. Keep in mind the solar cycle was at a minumum while the OHC rose in 1995/96.
Latitude says: “Bob, have you looked at how they tune the SST satellites?
When they do something “unexpected”, look at what they consider expected, and where that came from. SST’s staying the same or going down is “unexpected”, and obviously wrong. So they get re-tuned again……………”
Satellite-based SST data has a lower trend than buoy- and ship-based data.
If the sun goes “quiet” for an extended period (several decades at least) then would it be reasonable to assume that the radiative driver would favor La Nina episodes and that the step-wise graph would continue, but with the opposite slope?
TSI is a cyclical event that should not by itself change SST’s in any way that is measurable. There would be no lag to see. The trade winds and weather pattern cloud variations will greatly affect how much of that TSI gets into the ocean layers or gets mixed between the top solar warmed layer and the colder deeper level.
The ocean is a denialist? Be still my heart!
I don’t understand.
Figures 3 and 4 appear to show no trend outside of the steps that appear to be linked to El Nino events.
But you don’t attempt to explain where the additional energy comes from that triggers the step changes. Just because the supposed CO2 forcing is constantly increasing doesn’t mean that the climate system has to respond in the same manner.
So returning to the question “Does The Sea Surface Temperature Record Support The Hypothesis Of Anthropogenic Global Warming?” then the answer seems to be no, but equally it doesn’t appear to contradict it either.
Heat from a molecule of “greenhouse gas” can not warm the ocean and the reason is surface tension.The ocean will not accept physical heat only radiation.
So if ocean heat constant is fixed (+-TSI) Then how can ANY event affect the temperature upwards ONLY, as at each El Niño event over 30 years.
To suggest that there is no AGW you should have an explanation for the steps.
Personally I would suggest that your steps are just part of an upward trend with a 60 year cycle imposed. see:
http://3.bp.blogspot.com/-7xve50ZtMJ4/Te69400MiqI/AAAAAAAAAHk/t2xYavRh9_o/s1600/higher+level+trend.jpg
“When El Niño events dominate a multidecadal era, indicating the tropical Pacific is releasing and distributing more ocean heat than “normal”, global surface temperatures rise. The opposite holds true during epochs when La Niña events dominate.”
Agreed but what about trends from one El Nino dominated multidecadal era to the next?
Or from one La Nina dominated multidecadal era to the next?
We have some evidence from 1600 to date that there has been a slow irregular tropospheric warming since the depths of the LIA so it is likely that there has been a background warming trend that imparted its effects from one El Nino dominated multidecadal era to the next.
Likewise from MWP to LIA there would most likely have been a background cooling trend that imparted its effects from one La Nina dominated multidecadal era to the next.
The only candidate for that sort of pattern since long before industrialisation is changes in solar activity.
Where does the heat for these el niño events come from?
Looking at figure 4, following the 1998 el nino, we never then went below (or got near) the previous baseline, the green line. Following the recent el nino, we are possibly going to go below the previous baseline (the brown line) – I say likely since Dr Roy Spencer’s solar reflection data strongly indicates another bout of ocean cooling is under-way. The other notable thing is that the previous major el ninos each maxed out higher than its predecessors, the 2009 event did not.
IMO we’re in the process of experiencing a step down rather than a step up, but this won’t be confirmed for some time yet.
Imrancan – That is something about which there is much speculation and little knowledge. Obviously the process is taking place – I don’t think there is any doubt about the heating and cooling of the air by the sea. It was said for years that hte oceans are heated by the over-heating air, something that now seems to be a physical impossibility.
Is heat missing? If the computer model shows that there must be additional heat accumulating and the atmosphere is not getting warmer, then it is supposed to be ‘in the system’ somewhere. That is why Trenberth raised the question of where is the heat they ‘knew’ was accumulating (from CO2) was being stored. Obviously the oceans are a good guess if it is not showing up in atmospheric temperatures.
As long as the temeprature of all the seas and oceans is not well charcterised, it is pretty safe to keep on claiming (as some do) that the heat is stored in the oceans and will emerge just now to bite humanity. As more data is recorded showing that the heat in not in the ocean, the claim struggles for air. It has not yet breathed its last, but I see the ‘hidden heat’ argument floundering in a sea of contrary evidence.
having said that I see that on the smoothed data the 2009 event just pipped 1998.
I’m not following something here…the increase in SST implies an increase in the energy of the upper ocean. Are you saying that El Nino directly *provides* that energy? If so, from where is the energy taken? Or is it your hypothesis that the Earth absorbs more solar energy (or loses less) because of some aspect of the El Nino conditions, e.g. a change in cloud cover?
It seems a discussion of the relationship between total ocean heat content and SST’s would be useful as the longer-term warming signal from increased CO2 would favor being seen more readily in total OHC. Also, as the total amount of water vapor in the atmosphere over the oceans has been increasing over the years as clearly shown in SSM/I microwave analysis, The net energy this represents and causes (aside from the other effects) should be brought into the discussion. Finally, what does your analysis show for SST’s for the northern oceans, say north of 60 degrees?
Another way to show the irrelevance of the CO2 effect on the climate trends.
It appears that the Sun/Ocean interplay along with wind and clouds over the waters,is where the real Weather and Climate are the drivers of the worlds climatic patterns
The least squared trend re: total solar irradiance over the past 30 years is mildly negative. The least squared trend re: global SST over the past 30 years is strongly positive.
So you have proposed this ratchet effect whereby SSTs will increase ad infinitum, or do you suppose there is a cooling effect between these El Ninos that may be countered by AGW?
Re new step change in the post 2010 El-nino, Roy Spencer seems to think that SST hasnt rebounded – at least not yet? He is looking at whole of the world though….
http://www.drroyspencer.com/2011/07/global-sst-update-still-no-sign-of-resumed-warming/
Isn’t it too early to tell if we have another step change upwards in SST?
Very interesting. It seems Mr.Tisdale has single-handed refuted the CO2-hysteria. Congratulations to you, Mr. Tisdale!
The more you cut the planet into parts or types to look at Global Warming, the more you see that “global” is regional. Global warming is only global in a statistical sense, and the CO2 effect is only an effect in specific regions.
Look at SST data for the Pacific in a latitude basis year to year and you can see temperature movements from the equator towards the pole. The detail – not peer-reviewed, not properly documented – I have done looks like a movement of heat/energy through the oceanic and then air temperature through time.
Turn your temperature data 90* and plot vs time, so that the y-axis is latitude and the x-axis is time. Geologically we do this for x-axis position (lat-long) and y-axis depth (inverse time, greater depth is older), and call it a cross-section.