Guest post by Bob Tisdale
This is the second part in a series of posts about El Niño-Southern Oscillation (ENSO). They address many of the myths and misunderstandings about the tropical Pacific processes that herald themselves during El Niño and La Niña events. In them, I’m simply reproducing chapters from my recently published ebook Who Turned on the Heat?
For almost 4 years, my presentations about the long-term effects of El Niño and La Niña events indicate the global oceans over the past 30+ years have warmed naturally. The long-term impacts of El Niño and La Niña are blatantly obvious. Proponents of anthropogenic global warming apparently have difficulty comprehending that so they use misinformation to try to contradict what’s plainly visible. Many of the myths they’ve created are failed attempts to neutralize strong El Niño and La Niña events—to redirect the observable causes of the warming over the past 3 decades from natural factors to manmade greenhouse gases.
The following discussion is from Chapter 7.3 A New Myth – ENSO Balances Out to Zero over the Long Term.
***
A new myth about ENSO recently appeared in posts at the website SkepticalScience. This year one author there has been writing something to the effect of, El Niño and La Niña events balance out to zero over the long term. That’s nonsense, plain and simple nonsense. There are a number of ways to show the errors with this myth. The best way is to create a running total of NINO3.4 sea surface temperature anomalies.
Wikipedia provides an easy-to-understand explanation of a Running Total:
A running total is the summation of a sequence of numbers which is updated each time a new number is added to the sequence, simply by adding the value of the new number to the running total. Another term for it is partial sum.
The purposes of a running total are twofold. First, it allows the total to be stated at any point in time without having to sum the entire sequence each time. Second, it can save having to record the sequence itself, if the particular numbers are not individually important.
If, over the long term, El Niño and La Niña events balanced out to zero, then a running total of NINO3.4 sea surface temperature anomalies would equal zero. Does it? Refer to Figure 7-10.
El Niño and La Niña events obviously have NOT balanced out to zero over the past 30+ years. That curve of the running total of NINO3.4 data looks surprisingly similar to the global sea surface temperature anomaly curve. It’s really difficult to miss the very obvious increase.
I’ve actually had someone reply in a blog comment that 30 years was not long enough. I then provided a running total of NINO3.4 sea surface temperature anomalies starting in 1900. That early start year is pushing the boundaries when it comes to equatorial sea surface temperature data. The Panama Canal opened in 1914, and before then, equatorial Pacific sea surface temperature data becomes increasingly sparse.
The base years for anomalies would also impact the running total, especially one that long, so we need to pick some. Trenberth (1997) The Definition of El Niño stated that 1950 to 1979 was the best base period for NINO3.4 sea surface temperature anomalies. Trenberth writes:
Figure 1 shows the five month running mean SST time series for the Niño 3 and 3.4 regions relative to a base period climatology of 1950-1979 given in Table 1. The base period can make a difference. This standard 30 year base period is chosen as it is representative of the record this century, whereas the period after 1979 has been biased warm and dominated by El Niño events (Trenberth and Hoar 1996a). Mean temperatures are higher in the Niño 3.4 region than in Niño 3 and its proximity to the Pacific warm pool and main centers of convection is the reason for the physical importance of Niño 3.4.
We’ll use 1950 to 1979 as the base period for anomalies for our NINO3.4 sea surface temperature anomalies.
Figure 7-11 is the running total of HADISST NINO3.4 sea surface temperature anomalies, starting in January 1900 and ending in May 2012. It does not return to zero. However, it really looks like the global temperature anomaly curve.
The similarity between the curve of the running total of HADISST-based NINO3.4 sea surface temperature anomalies and a global temperature anomaly curve is remarkable. Unfortunately, it only works with HADISST-based NINO3.4 data. A running total of NINO3.4 data based on the ERSST.v3b or Kaplan datasets bears no similarities to the global temperature curve. Also, it only works with the base years of 1950-1979. That is, if you were to shift the base years so that they were weighted more toward El Niño events, like the period of 1971 to 2000, you’d wind up with a long-term running-mean curve that looks completely different. That makes the curve illustrated in Figure 7-11 a curiosity. Nothing more—just a curiosity, because I can’t justify the use of the base years of 1950-1979. It should definitely make you think, though.
That running total was one of the things that sparked my interest in ENSO. I discovered that curious running-total effect in April 2008, and presented it in a post titled Is There A Cumulative ENSO Climate Forcing? (ENSO isn’t a forcing, but that’s neither here nor there.) If you were to include the effects of volcanic aerosols and solar variability, the fit becomes even better. I presented that in a post titled Reproducing Global Temperature Anomalies With Natural Variables.
Regardless, ENSO has been skewed toward El Niño in recent decades. It has been skewed toward La Niña as well—the period from the 1940s to the mid-1970s for example. This is well known. We’ve shown the “skewness” in the preceding chapter using period average sea surface temperatures for the NINO3.4 region.
The myth that “El Niño and La Niña events balance out to zero over the long term” is simply another very obvious attempt to neutralize El Niño and La Niña. It’s a comical attempt that failed.
***
The illustration from a previous chapter I was referring to above was Figure 7-7 from Chapter 7.1 Myth – ENSO Has No Trend and Cannot Contribute to Long-Term Warming.
I’ll present that chapter next. (Hmm. Just noticed a typo. In the book, the illustration is identifed as Figure 5-7. I’ve corrected it here.)
SOURCES
The sea surface temperature data for Figure 7-10 was downloaded from the NOAA NOMADS website. NOAA uses 1971-2000 as base years. The dataset used in the other graphs is HADISST. It’s available through the KNMI Climate Explorer. There I’ve used the base years of 1950-1979 per the discussion above.
THE REST OF THIS SERIES
The remainder of this series of posts will be taken from the following myths and failed arguments. They’re from Section 7 of my book Who Turned on the Heat? I may select them out of the order they’ve been presented here, and I’ll try to remember to include links to the other posts in these lists as the new posts are published.
ALREADY PUBLISHED
1. El Niño-Southern Oscillation Myth 1: El Niño and La Niña Events are Cyclical. Refer also to the cross post at WattsUpWithThat for comments.
UPCOMING
Myth – ENSO Has No Trend and Cannot Contribute to Long-Term Warming
Myth – The Effects of La Niña Events on Global Surface Temperatures Oppose those of El Niño Events
Failed Argument – El Niño Events Don’t Create Heat
Myth – El Niño Events Dominated the Recent Warming Period Because of Greenhouse Gases
Myth – ENSO Only Adds Noise to the Instrument Temperature Record and We Can Determine its Effects through Linear Regression Analysis, Then Remove Those Effects, Leaving the Anthropogenic Global Warming Signal
Myth – The Warm Water Available for El Niño Events Can Only be Explained by Anthropogenic Greenhouse Gas Forcing
Myth – The Frequency and Strength of El Niño and La Niña Events are Dictated by the Pacific Decadal Oscillation
And I’ll include a few of the failed arguments that have been presented in defense of anthropogenic warming of the global oceans.
Failed Argument – The East Indian-West Pacific and East Pacific Sea Surface Temperature Datasets are Inversely Related. That Is, There’s a Seesaw Effect. One Warms, the Other Cools. They Counteract One Another.
INTERESTED IN LEARNING MORE ABOUT EL NIÑO AND LA NIÑA AND THEIR LONG-TERM EFFECTS ON GLOBAL SEA SURFACE TEMPERATURES?
Why should you be interested? Sea surface temperature records indicate El Niño and La Niña events are responsible for the warming of global sea surface temperature anomalies over the past 30 years, not manmade greenhouse gases. I’ve searched sea surface temperature records for more than 4 years, and I can find no evidence of an anthropogenic greenhouse gas signal. That is, the warming of the global oceans has been caused by Mother Nature, not anthropogenic greenhouse gases.
I’ve recently published my e-book (pdf) about the phenomena called El Niño and La Niña. It’s titled Who Turned on the Heat? with the subtitle The Unsuspected Global Warming Culprit, El Niño Southern Oscillation. It is intended for persons (with or without technical backgrounds) interested in learning about El Niño and La Niña events and in understanding the natural causes of the warming of our global oceans for the past 30 years. Because land surface air temperatures simply exaggerate the natural warming of the global oceans over annual and multidecadal time periods, the vast majority of the warming taking place on land is natural as well. The book is the product of years of research of the satellite-era sea surface temperature data that’s available to the public via the internet. It presents how the data accounts for its warming—and there are no indications the warming was caused by manmade greenhouse gases. None at all.
Who Turned on the Heat?was introduced in the blog post Everything You Every Wanted to Know about El Niño and La Niña… …Well Just about Everything. The Updated Free Preview includes the Table of Contents; the Introduction; the beginning of Section 1, with the cartoon-like illustrations; the discussion About the Cover; and the Closing. The book was updated recently to correct a few typos.
Please buy a copy. (Credit/Debit Card through PayPal. You do NOT need to open a PayPal account. Simply scroll down past where they ask you to open one.). It’s only US$8.00.
VIDEOS
For those who’d like a more detailed preview of Who Turned on the Heat? see Part 1 and Part 2 of the video series The Natural Warming of the Global Oceans. Part 1 appeared in the 24-hour WattsUpWithThat TV (WUWT-TV) special in November 2012. You may also be interested in the video Dear President Obama: A Video Memo about Climate Change.
“X, ENSO can’t be nonstationary as you claim because ENSO is not a stochastic process (or variable). It is a large set of variables or measurements, none of which are stochastic or stationary.”
Never made the claim that ENSO can’t be non-stationary. ENSO does however, if you take any set of variables or measurements, exhibit stationary behavior. Although that in itself does not prove that it is stationary or random, it does counter bogus claims (such as those made by Trenberth and Hoar back in 1997, and Bob Tisdale in this post) that the mean state of ENSO is changing.
The evidence is on the side of the stationary argument…it isn’t changing much if it is! The uptick in el nino activity at the end of a series, as argued by Trenberth and Hoar 1997, was destroyed by the prolonged La Ninas around, 2000, 2008, 2011 etc, which have cancelled the alarmist claims made by alarmists.
Whether it is random or not is an unknown, probably a mixture of the two. As for arguing that it doesn’t cancel out, I can only chuckle.
ENSO represents the global climate like no other phenomena on earth, the fact that it has little trend may suggest that the climate sensitivity is very low. Stable and Counteracting. A possible negative feedback. Why on earth would you argue the opposite?
You really do need to be careful what you wish for!
Your first assertion is incorrect. The proof that ENSO doesn’t balance out is the graph in the article that shows that the net result of ENSO over the satellite period does not balance – there is a net positive result.
As only one example is required to disprove a statement, your statement, as stated, is disproven.
Now, if you’d said “There is no proof that ENSO doesn’t balance out over a long period of time.”, then you’d be able to legitimately argue that the satellite period is not long enough. But if you do that, you’ll need to define how long is “a long period of time” because otherwise the statement is meaningless.
Your second assertion is equally incorrect because I’m sure someone can find a period of time over which ENSO does balance out (especially if they choose the period of time that corresponds to the baseline for the anomalies – it becomes trivial that ENSO will balance out for that period because, by definition, it will).
Again, you could refine your statement to include a period of time over which ENSO will balance out, but if you do that you’ll need to specify over which period of time that will be. As far as I know, no one has defined over what period of time ENSO is supposed to balance. Until then, it’s an unjustified assertion… effectively a “myth”, as per the title of Bob’s article
“Your first assertion is incorrect. The proof that ENSO doesn’t balance out is the graph in the article that shows that the net result of ENSO over the satellite period does not balance – there is a net positive result.”
Incorrect, the reason it doesn’t balance out in that particular case is entirely because the reference period of which the anomalies are related to are significantly cooler than the period in question. That has absolutely nothing to do with ENSO,…… IT IS A HUMAN CONSTRUCT. “NOAA uses 1971-2000 as base years” NOAA did it! Bob did by restricting it to the sat period! Wasn’t ENSO! It wouldn’t matter except for these silly cumulative sums!
The 70’s where anomalously cool, and do not make up a significant portion of the satellite period. Including the 70’s in the base period will distort the anomalies, making them warmer. When cos x is above the zero line, the cumulative sum (sin x) shots up like a rocket…….Hey, why not make one anomalously warm year, like 1997, the reference period? Imagine the global cooling trend cumulative sums would make! The trend in the example you gave is entirely dependent on the reference. Nothing to do with ENSO. No one uses cumulative sums for this reason.
“especially if they choose the period of time that corresponds to the baseline for the anomalies – it becomes trivial that ENSO will balance out for that period because, by definition, it will”
Excellent. I will get you to write my comments from now on! They or who or what are indeed CHOOSING whether it cancels out or not. Nothing to do with ENSO.
“Until then, it’s an unjustified assertion… effectively a “myth”, as per the title of Bob’s article”
ENSO series’ looks stationary. They tend to cancel out no matter what period. As much as I hate skeptical science…..they win
X, the physical processes cannot be stationary. In the neutral and La Nina phases, some of the stored energy is lost in the deep, that is, it warms 35 degree water to 35,5 degrees. For timelines that we care about that energy is gone. At the east end of the Pacific the upwelling cold water causes atmospheric cooling to a greater or lesser extent, but there’s no guarantee of any balance with the west end.
The El Nino phase can release all or most of the stored energy before it is lost provided the El Ninos are frequent enough. The El Nino also spreads more clouds to preclude more storage so it is self limiting. I don’t know if that’s what you are confusing with stationarity or not.
I like SkepSci because they are smart people but provide a living laboratory of how complete bias influences otherwise sound science. Like you, they are wrong with their concept of “balance” in climate processes and corresponding high (not low!) sensitivity to perturbations. They are right about CO2 being a diffused modulator of OLW but completely ignore the diffusion (or lack of diffusion) of water vapor as the primary modulator. They consider weather to be as balanced as ENSO (not true!)
You said: “ENSO represents the global climate like no other phenomena on earth, the fact that it has little trend may suggest that the climate sensitivity is very low. Stable and Counteracting. A possible negative feedback”
Completely wrong. The global warming and heat release from the 80’s / 90’s El Nino episodes is what strongly backs up my claim of low sensitivity (defined as warming from doubling CO2 or similar forcing). The current lack of extra heat release due to La Nina / neutral shows that CO2 has only the slow warming properties that backs up the low sensitivity argument. The negative feedbacks that limit the warming from ENSO or from CO2 or from any other variable factor are obvious to anyone who studies weather, ocean processes, etc.
HM, Bob Shapiro, Richard Telford, and, yes, X Anomaly have it right. If you calculate an integral, or a running total, on some function for which you have to choose the zero point, then you’ll see both the integral of that function, and a rising, falling, or zero trend that depends entirely on the choice of zero point, regardless of who or what you can reference for that zero point.
For taking a running total, the post gives the explanation:
OK, so we don’t have to sum it up each time, and we don’t have to record the original sequence–not that either is much of a problem for 30 years of data, using a spreadsheet. The real question is this: given that temperature anomalies are simply temperature referenced to a particular zero point, why do we want to add up temperatures? If you sum up temperatures, positive and negative, over 10 days, and get an answer of, say, 1.7 degrees, what is that? What are its units?
But there actually is such a measure as “degree-days.” It represents both time spent above (or below) a reference temperature, and the amount of temperature difference. For heating and cooling buildings, they use “heating degree-days.” These are summed temperature anomalies, with the zero point being the temperature where neither heat nor air conditioning are needed, perhaps 20 C or so. Heating degree-days are a proxy for total heat flowing in or out of the building, and give an indication of energy costs for heating and cooling. Farmers and gardeners use another kind of degree-day, the growing degree-day, to predict plant growth and flowering, etc. and also insect growth. The baseline temperature is taken as a minimum temperature for growth, and depends on the crop; 10 degrees C might be typical.
See http://en.wikipedia.org/wiki/Heating_degree_day and
http://en.wikipedia.org/wiki/Growing_degree_day
So, back to El Nino and La Nina: the effect we examine is, roughly, the transfer of heat from waters warmed by El Nino to the rest of the world, or from the rest of the world to the cooler waters in La Nina. That heat transfer depends on temperature difference, and the time that this difference operates, so we can use a kind of degree-days. For studying heat transfer during El Nino/La Nina events, using the 1950 to 1979 base period for NINO3.4 sea surface temperature anomalies isn’t going to work: there’s nothing in the area at that temperature for the heat to flow to. We have to use the temperature difference between water in the El Nino event, and water in the rest of the world. So, one could find the difference between, say, NINO3.4 sea surface temperatures, and global sea surface temperatures. Find this difference for each year, then take a running sum. If that sum shows a positive trend, you’re seeing heat flow, or potential heat flow, from El Nino to rest of the world.
Perhaps it would be better to use water temperatures in, say, an area around the tropical Pacific, instead of in the rest of the world. That’s one of those practical details. Also, this process would be much more complicated than working with heating degree days for a building, since ENSO events involve cloud cover changes and changing strength of trade winds, so temperature difference wouldn’t necessarily correspond so closely to heat transfer. But it would be a start.
When you start with the mean of 1950 to 1979 and use that as the baseline when you take a running total, you will be adding up the degree-days (roughly, heat contributions) of El Ninos and La Ninas since 1980. But you’ll also add up the shifting baseline of global temperatures themselves. Just looking at SSTs for El Ninos and La Ninas will include the effects of global temperature trends. Summing up those temperatures, expressed as anomalies, will also include an integral of the increasing global temperature upon which the ENSO temperature anomalies are riding. But that integral is included in figure 7-10 and 7-11 above; it’s clearly the main reason for the rising trends in these graphs. Subtracting global SSTs from the ENSO temperature anomalies before taking the running sum will remove that trend. Then any trend left will represent heat available to spread from El Nino to the rest of the world, and it will stand out clearly.
Nick Kermode, you said: “(…) in your example the only body accumulating energy is the ocean” and “For the temperature of both to increase they BOTH need to store more energy.”
As you might have noticed when reading my post, I wrote of the energy units originally received from the sun but subsequently partly transferred from the ocean to the atmosphere: “(…) most all of them are radiated back to space*. Not all, that is. The atmosphere will also gain a small surplus of energy, but its storage potensial is almost negligible compared to the ocean’s.
The point here is that the 100 energy units hypothetically entered (and most of them also left again) the Earth system in one single package, and that was it. In the real world these ‘packages’ come in a continuous flow. If the solar input exceeds the output (through the common available heat loss mechanisms) from the global surface over a certain time, heat (excess energy) WILL build up in the system, BOTH in the ocean AND (by extension, because it draws its heat from the ocean) in the atmosphere – they both warm.
A situation like this will for instance occur during a La Niña in the Pacific, and the buildup would be particularly noticable during a multiyear one. This is easily seen in the OHC data.
I have a hard time seeing why this is so difficult to comprehend …
Bob Tisdale says:
December 12, 2012 at 3:46 pm
richard telford says: “Even Bob Tisdale admits it ‘Also, it only works with the base years of 1950-1979’, so cherry-picks the baseline to get the results he wants, and creates yet another myth.”
That’s a odd interpretation, because it conflicts with what was written in the post. It leads everyone reading this thread to conclude that you hadn’t bothered to read the post–or that you have selective-quote syndrome. I haven’t cherry-picked the baseline. I gave a specific reason for selecting 1950-1979. If you’d like to criticize those years, please address your complaints to Kevin Trenberth. Second, I did not create a myth. I, in fact, cautioned about the graph, noting that Figure 7-71 was a curiosity. You might have understood that if you had read the post.
[snip . . you were answered politely, declaring a different response would have been forthcoming under other circumstances is an accusation of deceit . . mod]
JazzyT: Curiously, had looked into a discussion along those same lines a while back. As you could imagine, there would be numerous problems with any attempt to use the delta T. The eastern equatorial Pacific (NINO3.4 or Cold Tongue Index) sea surface temperatures haven’t warmed since 1900. They’re happy to be at about 27 deg C. But the rest of the global oceans have warmed around it from about 17.85 deg C to 18.45 deg C. During the satellite era, sea surface temperatures for the eastern equatorial Pacific are still the same, while globally they’ve warmed from 18.25 to less than 18.5.
I can’t see how that would resolve anything.
BTW, people are taking this much too seriously. I noted in the post that the running total in Figure 7-11 was a curiosity. I presented it in response to an argument by someone who has no understanding of the processes of ENSO.
X Anomaly says: “Never made the claim that ENSO can’t be non-stationary. ENSO does however, if you take any set of variables or measurements, exhibit stationary behavior. Although that in itself does not prove that it is stationary or random, it does counter bogus claims (such as those made by Trenberth and Hoar back in 1997, and Bob Tisdale in this post) that the mean state of ENSO is changing.”
Bogus claims? Hmm. Apparently you’ve never done something simple like smooth the annual HADISST-based NINO3.4 SST data with an 11-year filter.
http://i49.tinypic.com/zmfe6f.jpg
The decadal variations clearly show the basic state changes with time. ENSO basics. Anyone who’s familiar with ENSO understands that. Why don’t you, X Anomaly? Those persons following this thread will see that you’ve done a brief statistical analysis of a dataset, about which you know very little.
Have a nice day.
Mario Lento says: “Did I get it right? I do not want to misrepresent your science. I think you make a lot of sense and back it up with real observations.”
Mario, I didn’t say you were wrong. Sorry if you thought that. I simply added a little bit to the end of your description.
pochas says: “Well then, it will certainly end when the Rest-of-the-World’s oceans are as warm as the East Pacific. Or don’t you think it’ll go that far?”
The Rest-of-the World sea surface temperatures (not anomalies) have already reached the temperature of the East Pacific—or come close. I’ll be posting about it in a few weeks. It’ll be interesting to hear what people have to say, since we typically only look at anomalies. The reason it came up: someone thought there was a growing imbalance between the East Pacific and the Rest-of-the-World, when it’s the other way around. The Rest-of-the World data has been warming toward the East Pacific.
richard telford says:
December 13, 2012 at 6:15 am
Bob Tisdale says:
December 12, 2012 at 3:46 pm
richard telford says: “Even Bob Tisdale admits it ‘Also, it only works with the base years of 1950-1979’, so cherry-picks the baseline to get the results he wants, and creates yet another myth.”
That’s a odd interpretation, because it conflicts with what was written in the post. It leads everyone reading this thread to conclude that you hadn’t bothered to read the post–or that you have selective-quote syndrome. I haven’t cherry-picked the baseline. I gave a specific reason for selecting 1950-1979. If you’d like to criticize those years, please address your complaints to Kevin Trenberth. Second, I did not create a myth. I, in fact, cautioned about the graph, noting that Figure 7-71 was a curiosity. You might have understood that if you had read the post.
[snip . . you were answered politely, declaring a different response would have been forthcoming under other circumstances is an accusation of deceit . . mod]
I agree. I was very politely told that I hadn’t read the post. That just happened to be wrong.
Just like all those how insist that temperature records should start in 1998 and show no warming, but insist that they are not cherry picking, Tisdale has chosen to use 1950-1979 as his baseline and of course he isn’t cherry picking. He has found a justification. An equally good justification could no doubt have been found for using any other period as a baseline, and as has been shown by many here, the choice of the baseline affect the trend in the running total.
In a period of stable climate, ENSO will be stationary. That is will have the same mean and variance, measured over appropriate time scales, at any time. If the global climate changes, it is mathematically impossible for the mean and variance of ENSO not to change. Over the last 30 years, the global mean climate has warmed, so it is not possible for ENSO to have remained unchanged. Why would anybody expect otherwise?
Bob Tisdale said: “The reason it came up: someone thought there was a growing imbalance between the East Pacific and the Rest-of-the-World, when it’s the other way around. The Rest-of-the World data has been warming toward the East Pacific.”
Very interesting.
This portrays, as a matter of fact, the same phenomenon going on with the global energy imbalance. People think it’s growing. The opposite is true. It’s getting smaller and smaller. Why? The processes of latent heat transfer, sensible heat transfer (conduction/convection) and net thermal radiation have all become gradually more efficient at ridding Earth’s surface of its excess heat, eating up the solar surplus that’s been leading since the late 70s. The planet’s total heat loss is a fair bit greater today than 30-35 years ago, all thanks to and as a direct function of the increasing surface and hence tropospheric temperatures. Within the same period, mean insolation at global ground/sea level has remained fairly stable – rising somewhat up to the early-mid 2000s but subsequently falling back down to 1979 level. And yet, the Earth system is still gaining heat, albeit at a steadily slowing rate, having recently all but stalled. Within just a couple of years we might actually cross the line back into negative territory …
Increasing total global heat loss during warming/accumulation of heat? Cannot be if the atmosphere were the driving force. The atmosphere can only limit heat loss (either suppress it or keep it at balance) to force heat accumulation and warming. It simply knocks the bottom out the whole notion that AGW is behind the global warming we’ve experienced since the 70s. While reinforcing Bob’s ENSO explanation.
@Bob Tisdale says:
December 13, 2012 at 7:22 am:
Thank you Bob, for your feedback. I learn more from getting it wrong… and just wanted to be sure I was not misrepresenting your teachings! That would serve me poorly and others that I engage. Like most, I appreciate your help in understanding the mechanisms that lead to changes in climate, especially given that there is way too much bad information out there.
Mario
Bob Tisdale says:
December 13, 2012 at 7:33 am
“The Rest-of-the World sea surface temperatures (not anomalies) have already reached the temperature of the East Pacific—or come close. I’ll be posting about it in a few weeks.”
I’m, looking forward to it. I hope you will document the history of this narrowing of the range of ocean temperatures.
Bob,
it’s simply that your argument …
“If, over the long term, El Niño and La Niña events balanced out to zero, then a running total of NINO3.4 sea surface temperature anomalies would equal zero.”
… is not valid.
The reason is that even if a time series (e.g.: a sine) would perfectly balance out to zero over the long term this will not be the case if it contains some random error component – even if this component also finally balances out to zero as well. This is because the error component when integrated by a running total will result in a random walk behaviour. So this integration test simply doesn’t prove that ENSO does not balance out to zero over the long term. It’s as simple as that.
The ENSO issue goes to the heart of the scientific question of climate dynamics, it is the sort-of lynch-pin of the issue. A lot of people here are having difficulty with the idea of something like ENSO moving global temperatures up or down. This is because the fallacy that lies at the heart of much current climate science is the total passivity of the climate. We are led to believe that the climate system is passive and that only upper atmosphere radiative balance is of any significance in any warming or cooling trend. This narrow and ignorant view excludes any consideration of the atmosphere-ocean as a complex system with non-equilibrium chaotic dynamics and huge heat capacity in the oceans. Internal climate dynamics can feed back to cloud albedo so that radiative forcing is not a simple linear constant.
Oddly if you look at the field of palaeo climatology and the ocean simulations of glaciation and interglacials over the last million years or so, looking at phenomena such as the bi-polar seesaw north-south oscillations at the start and end of interglacials (like the seesaw that is starting now) it is well established that the ocean circulation alone can drive millenial scale fluctuations and oscillations in global climate. The disconnect between this understanding and other atmospheric climate science writing of ENSO as “noise” is astonishing. It never fails to amaze me how primitively territorial scientists in general are. There can be almost zero communication between different fields / tribes.
Think just for a moment about the oceans and all this nonsense about atmospheric forcing and climate passivity will evaporate.
Sorry for the delay in replying.
richard telford says: “In a period of stable climate, ENSO will be stationary.”
When is climate stable?
richard telford says: “That is will have the same mean and variance, measured over appropriate time scales, at any time. If the global climate changes, it is mathematically impossible for the mean and variance of ENSO not to change. Over the last 30 years, the global mean climate has warmed, so it is not possible for ENSO to have remained unchanged. Why would anybody expect otherwise?”
You miss the obvious, richard. Global temperatures are responding to ENSO…
http://bobtisdale.files.wordpress.com/2012/12/figure-8-row-a.png
…not vice versa. In other words, you’ve got cause and effect backwards.
Bob Tisdale says:
December 13, 2012 at 6:56 am
Well, the difference between 18.25 deg C and 18.5 deg C, i.e., 0.25 deg C, is not much. But, if the sea had suddenly warmed by that amount and the anomalies were riding on top of that, then by adding up anomolies over 30 years, youur +0.25 deg would give you 7.5 degree-years extra over that period. Of course, the oceans gradually warmed up over that period, so you’d need to cut that figure in half, and get something more like 4 degree-years. That is, perhaps, 1/6 of what the actual trend in the graph seems to be
Then again, it’s not the entire ocean that serves as a heat sink for El Nino, it’s just the nearby portion. So, from the backs of three envelopes, as it were, a warming of about 1.5 degrees in the tropical Pacific would account for this. I think that’s more than has been observed, but other effects would also have to be accounted for.
One thing is clear, as you mentioned, there would be a lot of problems trying to nail this down using Delta T.
Perhaps–but it’s kind of fun, and once in a while, something useful falls out of such discussions.
JazzyT says: “…and once in a while, something useful falls out of such discussions.”
And that’s why we do it.
Regards
Bob Tisdale says:
December 15, 2012 at 3:19 am
richard telford says: “In a period of stable climate, ENSO will be stationary.”
When is climate stable?
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It never is as forcings are changing on all time scales. But that does not preclude considering the properties of a stable climate, such as equilibrium climate sensitivity.
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richard telford says: “That is will have the same mean and variance, measured over appropriate time scales, at any time. If the global climate changes, it is mathematically impossible for the mean and variance of ENSO not to change. Over the last 30 years, the global mean climate has warmed, so it is not possible for ENSO to have remained unchanged. Why would anybody expect otherwise?”
You miss the obvious, richard. Global temperatures are responding to ENSO…
http://bobtisdale.files.wordpress.com/2012/12/figure-8-row-a.png
…not vice versa. In other words, you’ve got cause and effect backwards.
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Your graph shows that ENSO variability affects global mean temperature. That has been known for decades. It does not demonstrate that the trend in global temperature is caused by ENSO.