An Illustrated Introduction to the Basic Processes that Drive El Niño and La Niña Events

El Niños and La Niñas are parts of naturally occurring, sunlight-fueled processes—amazing processes—that produce warm water and redistribute it from the tropical Pacific. When I was first able to fathom the processes, when they finally clicked for me, I was in awe of Mother Nature’s handiwork. Cloud cover, sunlight, ocean heat content, sea surface temperatures, sea level, surface winds, ocean currents, etc., all interwoven, all interdependent, with the events occurring at massive scales. I’ve been sharing their complexity, magnitude and aftereffects ever since. Hopefully, this post will allow you to gain some insight–or spark your interest.

El Niño and La Niña events are extremely important parts of Earth’s climate. They are the dominant mode of natural climate variability on annual, multiyear and decadal timeframes. El Niño and La Niña events impact everything from drought and rainfall to surface temperatures around the globe. Consider this: El Niños and La Ninas occur in the tropical Pacific, but more than a decade ago it was determined that they rearranged sea ice in the Southern Ocean surrounding Antarctica. Recently, they were even linked to temperature of the water below the Antarctic sea ice, through changes in ocean wind patterns. See Dutrieux et al. (2014) Strong Sensitivity of Pine Island Ice-Shelf Melting to Climatic Variability and the corresponding ScienceDaily article here.

The following is Section 1 from my ebook Who Turned on the Heat? This presentation was created to fill the gap between overly scientific texts and the basic (but way too simple) descriptions of El Niño and La Niña processes that are available on the internet. As I noted above, hopefully, it will help you to understand those seemingly complex processes. Please ask questions.

Notes: I’ve struck through text from the book (strikethrough) where it refers to other sections of the book, and I deleted a short note that refers to a feature of Abobe readers (the book is in pdf format). This post contains 29 illustrations, so it may take a little while to load. If they don’t appear full-sized, just give them a click.

[START OF SECTION 1 OF WHO TURNED ON THE HEAT?]

1.1 Preliminary Discussion of the ENSO Annotated Illustrations

Most introductions to the El Niño-Southern Oscillation (ENSO) on the web include boiler-plate descriptions and three illustrations: one each for El Niño, La Niña and ENSO-neutral phases. The reader has to jockey back and forth, scrolling up and down, to read the text and compare it to the illustrations. Unfortunately, much of what’s discussed in the text of those ENSO introductions isn’t shown in the graphics. To overcome that, I’ve prepared a 29-cell series of annotated (cartoon-like) illustrations that first introduce readers to background information about the Pacific Ocean. There are also introductions to trade winds and ocean currents, both of which have important roles in ENSO. With multiple cartoon-like illustrations for each phase and the transitions between them, the reader is taken through a complete cycle of ENSO phases: ENSO neutral to El Niño, back to ENSO neutral, on to La Niña, and then back to ENSO neutral. At each phase, the interaction between sea surface temperatures across the tropical Pacific, trade winds, sea surface height, precipitation and subsurface ocean temperatures are illustrated and discussed. Also presented are the differences between El Niño and La Niña events and the reasons why global surface temperatures vary in response to ENSO events.

To reinforce and confirm what’s presented in this section, Section 3 includes more-detailed, data-reinforced descriptions and illustrations.

1.2 The ENSO Annotated Illustrations

1 Global Oceans

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2 Pacific Ocean 2

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3 Rotation and Trade Winds

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4c Trade Winds and Currents

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5 Trade Winds and Currents2

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6 Intro to Cross Section

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7 ENSO Neutral a

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8 ENSO Neutral b

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9 ENSO Neutral c

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10 ENSO Neutral d

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11 ENSO Neutral e

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12 transition to el nino

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Now’s a good time to take a quick break from the cartoon-like illustrations. We’ll go into more detail in Section 3 about the interrelated processes taking place before an El Niño, but it’s important now to reinforce what’s been discussed so far. I’ll reword the presentation a little with hope that it will help make things click for you.

The trade winds are an important part of our discussion of ENSO-neutral, or “normal”, conditions in the tropical Pacific. They blow from east to west across the surface and cause the surface waters to also travel from east to west. That makes sense. If you blow on a liquid long and hard enough, the surface of the liquid will move it the direction you’re blowing.

The trade winds also blow clouds toward the west. That’s not hard to imagine, either. This allows that wonderfully strong tropical sun to beat down on the surface of the tropical Pacific and to reach into the subsurface waters to depths of 100 meters. Though most of that sunlight is absorbed nearer the surface, in the top 10 meters (roughly 33 feet) or so, it does reach farther. All of Mother Nature’s glorious sunlight warms the tropical Pacific waters as they travel west.

The trade winds push the waters up against the land masses of Indonesia and Australia. This causes the warm water to, in effect, pile up in the western tropical Pacific, in an area called the west Pacific Warm Pool. The trade winds driving the westward movement of surface waters also draw cool waters from below the surface of the eastern equatorial Pacific, in a process called upwelling. That upwelled water provides a continuous source of cool water at a relatively constant temperature that’s then warmed by the sun as it travels west. The water is, therefore, cooler in the eastern equatorial Pacific, in an area called the Cold Tongue Region, than it is in the west Pacific Warm Pool. Remember, the tropical Pacific stretches almost halfway around the globe, so that nice cool supply of water in the east travels a long way under the tropical sun before it reaches the warm pool in the west.

The trade winds cause the temperature difference between the east and west portions of the tropical Pacific. Now, here’s the interesting part. The temperature difference between the eastern and western tropical Pacific causes the trade winds to blow. That’s right. The temperature gradient of the tropical Pacific sea surface temperatures and the trade winds interact with one another in a positive feedback loop called Bjerknes feedback.

Why does that happen?

There nothing mysterious going on. The warmest water is in the western tropical Pacific. We’ve discussed that, and we’ll confirm it in Section 3. The warm water there heats the air above it, and that relatively hot air rises. All of that rising hot air has to be replaced by other air, and it’s the trade winds out of the east that supply the necessary make-up air. Because the tropical Pacific is cooler in the east, the air sinks there, and eastward-blowing upper winds complete the circuit. Overall, the warm air rises in the west; it cools as it’s carried east by the upper winds; then it sinks in the eastern tropical Pacific, where it heads back to the west as the trade winds. That circuit is called a Walker cell. The trade winds continuously push cool water from the east to the west, sunlight warms the water as it travels west, and when that warm water reaches the west Pacific Warm Pool, it supplies the heat necessary to maintain the updraft, which, in turn, causes to trade winds to blow. The briefest way to explain it: the trade winds and the sea surface temperatures are coupled, meaning they interact with one another.

With all of that warm water being piled up in the western tropical Pacific, and with all of the cool water being drawn from the eastern equatorial Pacific, the surface of the water—the sea level—in the west Pacific Warm Pool is about 0.5 meters (approximately 1.5 feet) higher in elevation than it is in Cold Tongue Region in the east.

Everything’s in tune, running in its normal state. The temperature difference between the east and west keeps the trade winds blowing—and—the trade winds maintain the temperature difference between east and west—and—the trade winds keep the warm water in the west Pacific Warm Pool at a higher elevation than it is in the eastern equatorial Pacific.

We can’t forget about gravity. It’s always there, our constant companion. Gravity would like the sea surface height in the west to equal the height in the east. It likes level playing fields. It’s working against the trade winds, and the trade winds are piling up the warm water against gravity. Still, everything is in relatively constant state of balance, with little gives and takes here and there.

Then some weather event—and that’s precisely what it is, a weather event or group of weather events—causes the trade winds to relax. That means the coupled ocean-atmosphere processes taking place in the tropical Pacific are no longer in balance. Sometimes, the weakened trade winds aren’t strong enough to hold the warm water in place in the west Pacific Warm Pool against gravity, so gravity takes over and all of that lovely warm water that was piled in the west Pacific Warm Pool suddenly sloshes to the east. That’s how an El Niño starts.

I’m now going discuss parts of the process that haven’t been shown in the illustrations yet.

The Pacific Ocean is awfully wide at the equator, so it takes a while, about 2 months, for the warm water to slosh to the east as far as the coast of South America.

Let’s put things into perspective. The west Pacific Warm Pool holds a massive amount of warm water. It varies in size. When it’s large, the west Pacific Warm Pool can cover a surface area of about 19 million square kilometers (7.3 million square miles) but it averages about 12 million square kilometers (4.6 million square miles). Numbers that large are hard to embrace, so, when the west Pacific Warm Pool is larger than normal, think of an area the size of Russia or a little less than twice the size of the United States. Refer to the Mehta and Mehta (2004) presentation Natural decadal-multidecadal variability of the Indo-Pacific Warm Pool and its impacts on global climate. Also imagine the warm water reaches depths of 300 meters (about 1000 feet). Sometimes, during a very strong El Niño, most of that water from the west Pacific Warm Pool will be transported east and much of it will spread across the surface of the central and eastern tropical Pacific. Now remember that the Pacific stretches almost halfway around the globe at the equator. An El Niño dwarfs all other weather-related events. How big are they? Sometimes it takes a pair of tropical cyclones just to trigger an El Niño. Yes, tropical cyclones as in hurricanes.

Let’s return to the ENSO-neutral phase for a second. A weather event—for example, a couple of tropical cyclones or a pair of them that straddle the equator—a weather event that’s teeny by comparison, has caused the Pacific trade winds to relax, which in turn has unleashed a monstrously large phenomenon that is capable of raising global temperatures 0.4 degrees C in less than a year. In turn, there are heat waves and cold spells. Floods will strike some parts of the globe. Drought conditions form in others. Snowfall will pile to record heights in some areas, and in others it will decrease. These effects were studied and documented decades ago, and they’re still being studied, for example, to account for differences between Central Pacific and the more powerful East Pacific El Niño events.

Of course, some publicity seeking climate scientists continue to (very unwisely) blame carbon dioxide for the heat waves and cold spells, flooding and drought, blizzards and low snowfall, creating further disbelief in climate science. They have only themselves to blame for their loss of credibility. I digress.

An El Niño is one of Mother Nature’s ways of reminding us who’s in charge.

Back to the cartoon-like illustrations.

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13 el nino a

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14 el nino b

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15 el nino c

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16 central el nino base

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17 east pacific el nino

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18 Transition to ENSO Neutral a

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19 Transition to ENSO Neutral b

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20 Transition to ENSO Neutral c

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21 La Nina a

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22 La Nina b

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23 La Nina d

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24 Transition from La Nina to ENSO Neutral a

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25 Difference Between el NIno and La Nina

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26 Difference Between el NIno and La Nina

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27 What Causes Rise in Global Surface temps

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28 What Causes Rise in Global Surface temps2

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29 What Causes Rise in Global Surface temps3

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1.3 Recap of Section 1

Trade winds cause the sea surface temperature and height in the western tropical Pacific to be greater than they are in the east. El Niño events are started by the weakening of the trade winds. The weaker trade winds can no longer hold the warm water in place in the west Pacific Warm Pool, and this allows gravity to carry the warm water east, raising sea surface temperatures in the central and eastern equatorial Pacific.

El Niño events are the abnormal phase of ENSO. The Equatorial Countercurrent strengthens and carries a large volume of warm water from west to east, and that increased volume from west to east opposes the normal east-to-west flow during ENSO-neutral and La Niña phases. The winds also change directions during an El Niño, with trade winds becoming westerlies in the western tropical Pacific. On the other hand, during ENSO-neutral and La Niña phases, the trade winds are blowing in their normal east-to-west direction.

La Niña events are easy to describe. They are exaggerations on the ENSO neutral phase. However, La Niña events play the important role of replenishing the heat given off by the El Niño that precedes it, and sometimes a La Niña can create more warm water than was released by the El Niño.

Warm water that has traveled east during the El Niño and that is not “exhausted” by the El Niño does not remain in the eastern tropical Pacific. It is returned to the West Pacific and Indian Oceans, where much of it remains on the surface. Before the El Niño, most of that warm water is below the surface of the west Pacific Warm Pool and excluded from the surface temperature record. Then, after the El Niño, part of what remains of that warm water is now on the surface of the West Pacific and East Indian Oceans. The opposite does not occur during the La Niña phase. The result: strong El Niño events can raise global sea surface temperatures for extended periods of time. This will be discussed in detail in Section 5.

[END OF SECTION 1 OF WHO TURNED ON THE HEAT?]

Again, if you have any questions, please ask.

Now that you’ve run through the processes, here’s a one sentence description of ENSO: ENSO acts as a chaotic, naturally occurring, sunlight-fueled, recharge-discharge oscillator, where the La Niña phase acts as the recharge phase and El Niño acts as the discharge phase.

As long as the climate science community continues to treat ENSO as noise, they will make little progress in understanding the natural contribution to global warming, and it’s a sizeable contribution. We’ve discussed for years that the climate science community has failed to account for the “leftovers”, the residual warm water, from strong El Niños.

I also used those cartoon-like illustrations in my two-part video series “The Natural Warming of the Global Oceans”, which first aired on the WUWT-TV special in September 2012. That series is available on YouTube. Part 1 is here, and Part 2 is here.

I went into much more detail to explain ENSO processes and the aftereffects of El Niño and La Niña events in my ebook Who Turned on the Heat? I’ve lowered the price of Who Turned on the Heat? from U.S.$8.00 to U.S.$5.00…for a month or so, with hope of increasing sales a little bit. A free preview in pdf format is here. The preview includes the Table of Contents, the Introduction, the first half of section 1 (which was provided complete in this post), a discussion of the cover, and the Closing. Take a run through the Table of Contents. It is a very-detailed and well-illustrated book—using data from the real world, not models of a virtual world.

Who Turned on the Heat? is only available in pdf format…and will only be available in that format. Click here to purchase a copy. Thanks. Unless I can find funding for my research, it will be book sales and tips/donations that allow me to return to blogging full-time.

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Eric Webb

Nice post Bob, only one concern, this ” Consider this: El Niños and La Ninas occur in the tropical Pacific, but more than a decade ago it was determined that they rearranged sea ice in the Southern Ocean surrounding Antarctica.” Considering the link you provide is from GISS, my confidence in the validity in this claim is astoundingly low. Not to mention that some serious caution needs to be used here to ensure that there is a “significant” relationship between these two events as the Antarctic Circumpolar Current (ACC) that was established millions of years ago upon Antarctica’s split from Australia makes this area relatively more independent of oceanic “outside” influences like ENSO.

Steve

Great article Bob. Found it while supervising a 3 hour exam and the cartoons were an excellent way to get a handle on these weather events. Many thanks.

Excellent, Bob.
It’s all beginning to make sense for me now.

David

Hi Bob – excellent post. Thank you. One typo in the very last line “… return to bogging…”

johnmarshall

Another article to add to those already saved. Many thanks Bob, don’t let work get you down.

Peter Czerna

Excellent work – exemplary!

AndyG55

Bob, When an El Nino occurs, there would also be a large release of energy just from the change in sea surface levels, wouldn’t there?
I mean 0.5m at one side of the Pacific must have one heck of a lot of potential energy.

Very well done!! Drawings aid understanding to a considerable extent.

Bloke down the pub

Thanks Bob. Perhaps a line or two to explain the role of the Earth’s rotation on the direction of the trade winds might be a useful addition?

M Courtney

AndyG55, surely the lowering of the West Side of the Pacific is matched by the raising of the rest of the Ocean? It should cancel out.

Well done! I frequently used careful cartoons in my work, teaching complex systems.

DocMartyn

That is a really good presentation, I am impressed by you simple, but well thought out, graphics.
Do we have measurements of surface salinity across the pacific during a full cycle?

Gail Combs

Excellent. Bob’s presentation in the WUWT-TV special in September 2012, was the first time I really understood ENSO.
His book should be a textbook. (At +$100/ a pop)

richardscourtney

Bob Tisdale:
Severe thanks for your excellent article above which provides a clear introduction to ENSO effects.
I write because I was much saddened that circumstances have forced you to stop blogging. The above article demonstrates we have not completely lost you, and that is very good to know.
As Pielke snr. said, it would be good if your work were to obtain funding from your government which – sadly – chooses to waste such monies on flawed climate models.
Richard

Hmmm

I never really understood El Nino/La Nina before this; that was extremely concise and informative for a layman to comprehend! Which leads me to my questions, which I’m guessing you go into in the rest of your book…. Why are there decades long La Nina and El Nino dominant phase cycles? And what is the PDO and is that the driver of my first question? And how long does it take to dissipate the heat from El Ninos (less than a year? multiple years?)

Hmmm

So if they treat these oscillations as white noise they are oversimplifying (and discounting) a natural source of temperature variation which leads them to over-estimate attribution and sensitivity calculations.

jlurtz

Excellent Job!!!!

Hmmm

Now I need to go back and read your previous posts on how folks try to “remove” the influence of ENSO from the temperature record. I seem to remember you criticizing the fact that much of the residual warm surface water remains long after the actual El Nino event and they were therefore not correcting for El Nino’s properly. I don’t recall whether you opined whether this adjustment can be done at all or offered an alternative adjustment of your own.

Joe Public

Thanks for your effort Bob. Pictures really are worth a 1,000 words.

FrankK

And of course Bob tied in with all you have indicated is the Southern Oscillation Index that indicates the likely weather conditions in Eastern Australia.
http://www.bom.gov.au/climate/glossary/soi.shtml
“The Southern Oscillation Index, or SOI, gives an indication of the development and intensity of El Niño or La Niña events in the Pacific Ocean. The SOI is calculated using the pressure differences between Tahiti and Darwin.
Sustained negative values of the SOI below −8 often indicate El Niño episodes. These negative values are usually accompanied by sustained warming of the central and eastern tropical Pacific Ocean, a decrease in the strength of the Pacific Trade Winds, and a reduction in winter and spring rainfall over much of eastern Australia and the Top End. You can read more about historical El Niño events and their effect on Australia in the Detailed analysis of past El Niño events.
Sustainted positive values of the SOI above +8 are typical of a La Niña episode. They are associated with stronger Pacific trade winds and warmer sea temperatures to the north of Australia. Waters in the central and eastern tropical Pacific Ocean become cooler during this time. Together these give an increased probability that eastern and northern Australia will be wetter than normal. You can read more about historical La Niña events and their effect on Australia in the Detailed analysis of past La Niña events.”
Wetter, drier nothing to do with fictional “CO2 induced climate change” but every thing to do with sun induced weather circulation and dynamic ocean heat conditions.

Green Sand

Excellent Bob! Mega!
Anybody who wants to get an idea of what is happening now see the following from BOM – “4-month sequence of vertical temperature anomaly sections at the equator, Pacific for January 2014” for the present day conditions:-
http://www.bom.gov.au/cgi-bin/oceanography/wrap_ocean_analysis.pl?id=IDYOC007&year=2014&month=01
Updated approx every 4 days so it is possible to observe any developments.
From the following data set with snapshots back to 1997 (Full) and 1980 (Partial)
“4-month sequence of vertical temperature anomaly sections at the equator, Pacific”
http://www.bom.gov.au/oceanography/oceantemp/pastanal.shtml

Looking forward to how the change in the “Pacific” circulations influences the circumpolar current that connects all the oceans.
The “after el Niño” circulation appears (to me) to add to the circumpolar current, pushing more water through Drake’s Passage and increases the rate of circulation of the Atlantic in the Weddel Sea. Without knowing the magnitude of the change, it’s hard to tell if and how the Indian Ocean currents could change. Those are important to me because they’re outside my “front door”.
There are distinct changes in weather patterns (aka “climate”) in the SW of Western Australia along with the Pacific oscillations. Especially the multi-decadal ones which seem to bias the strength and recurrence of the “phases”.
Of course the Indian ocean is big enough to be a significant solar energy sink and emitter with its own oscillations. It doesn’t however substantially span the equator as does the Pacific.
The Atlantic Oceans OTOH do span the equator but may not be wide enough (only about 4 hours at its widest) to establish currents and sinks in order to oscillate.

Kelvin Vaughan

Love the cartoons. Really helpful for my old brain. Thanks.

Paul Hanlon

Hi Bob,
Thanks for the opportunity to show some gratitude for the wonderful education you have given us all. I’m only sorry I didn’t do it more and sooner. Happy new Year to you, and let’s hope you get recognised for the wonderful contribution you have made to climate science.

Birdieshooter

Outstanding. I have been able to put all these ideas in a simple cohesive whole in a few minutes better than having tried from reading bits and pieces over the last few years.
Given the pushing of the water to the west, is this the reason some of those South Pacific islands are the focus of a lot of attention about sea level rise threatening their existence? How much variance in that rise would they experience over say a 20 or 30 year period? I had thought much of the concern might have been subsidence but it appears these cycles add to the levels as well.
Thanks for a terrific and helpful piece.

BBould

Outstanding post! For the first time I think I now understand El-Nino, La-Nina and ENSO. Thanks so much!

Alan Robertson

DocWat says:
January 10, 2014 at 4:13 am
Very well done!! Drawings aid understanding to a considerable extent.
_______________________
No kidding. Even I get it.

Thanks Bob, an excellent article!
The right amount of simplification and good illustrations.

The drawings are perfect, they really help to understand this complex and very natural/normal behavior.

Ron Richey

Sweet! – I actually get thisnow. Only took about a half hour.
Thanks Bob.
Couple of “dummy” questions:
What happens to ENSO during an ice age?
Does ENSO cause or contribute to ice ages or warm ages?
Ron Richey

Cassian

Bob, thank you for your explanation. I have never taken the time to understand these events. With your explanation, I learned both the mechanism and the importance of these events enough to explain both aspects to others. Thanks again. I’ll be buying the book.

Resourceguy

A keeper

Data Soong

Excellent description. It helped me to understand the entire process more completely.

Scotty the Red

There is an interesting article at: http://cimss.ssec.wisc.edu/goes/blog/archives/14716 “Tehuano wind event in the wake of a strong eastern US winter storm,” that shows when a strong cold front reaches and crosses Mexico east of the Yucatan which causese strong off-shore flow on the Pacific side.
Perhaps this flow may increase upwelling and phase with other ingredients that cause or force La Nina events? Just a thought.

Resourceguy

So an El Nino directs surface warming streams at the area off the coast of Africa where hurricanes and tropical waves form in the Atlantic. This raises the question of whether poor hurricane season predictions are the direct result of lack of predictability of El Ninos or have we entered the era of boilerplate bureaucratic press releases for hurricane season predictions tipped to the active side by the likes of John Holdren at the White House?

James Strom

Good stuff, Bob. You’ve answered a question that has been nagging me for quite a while: Is the warming associated with El Nino merely a rearrangement of existing heat or somehow an addition to the Earth’s total heat energy? To a significant degree it must be the former. As you say the waters of the warm pool get moved into locations where they are more fully available to our efforts at measurement. So your essay also points to a significant source of error in our measurment of global temperature.

fritz

Perhaps I read to fast ; but what happens with the global sea level during these events ; I read that it increases during El Nino events because rain falls in the sea , while during La Nina , rain falls over Land ; that comparison is only true for what you call Central Pacific events ; other question : the transfer of heat from the sea to the atmosphere should normally decrease its thermal expansion ; do you have made calculations about the impact of both factors to the global sea level heigth ?
Sorry for my English

Gary Pearse

Excellent exposition to cement my understanding. One small question: part of the difference in sea-level will be due to lower density of the amassed warm water, or is it of higher salinity to counterbalance this reduction in gravity or even add to it?

Michael Barnes

Curiosity question: Since the water in the West Pacific Warm Pool is warmer than the water in the Cold Tongue Region, the water in the West is less dense than the water in the East. Is this explicitly accounted for? How much does it matter?
Thank you for the pictures.

PeterB in Indianapolis

Bob,
Excellent work as usual! My question for you is this:
It seems like we have been bouncing around in then ENSO-Neutral range for quite some time now. Do you see a “breakout” in one direction or another any time soon? Right now it looks like we are getting “teased” with a potential La Nina, but we still can’t seem to break out of the neutral range. Do you think we will remain in the neutral range for some time yet, or are we due (or overdue) for a La Nina or an El Nino?

Lance Wallace

If ENSO is just a natural oscillation, why do we see these step-like shifts in global atmospheric temperatures after powerful El Ninos such as 1997-98?

Rich Carman

Bob, great post. Much appreciated. Question 1: When global warming and global cooling do actually occur over extended periods of time (such as variations in thr earth’s orbit or sun’s activity), how might this affect the intensity of the processes you described? Question 2: I haven’t seen the video yet, but is it possible to make a widely distributed motion animation of these processes? If so, how might that be accomplished? Question 3: What kind of resistance have you run into with respect to this information?

Hmmm

Lance- my guess is that effect is due to the residual warm water which does not go back to the Pacific warm pool but gets circulated poleward and into the Indian Ocean releasing heat for years after. I’m sure his book goes into this. Therefore if you look at it on a short timescale it might look like permanent step changes. Which means if you are going to treat this as noise that cancels itself out in the short-term, and do attribution/sensitivity calculations based on observational data without some sort of valid correction for ENSO and it’s true long-term modes and effects, then you are going to fool yourself. And based on the ENSO mode (El Nino dominant) we were in during the IPCC analysis, they over-attributed the warming and sensitivity to CO2 by improperly ruling out natural variability effects of ENSO. By how much is the question…

JimS

Kudos Mr. Tisdale – an article well worth saving to my bookmarks.

Sean Peake

Well done. All it needs is a big bow to wrap it up

Andy Halloran

What causes trade winds to become stronger during a La Nina?

Gunga Din

Thank you.
What makes your understanding of this part of “Global Climate” a treasure is your ability to communicate it in a way understandable to people like me.

This all sounds absolutely wonderful. However you, like the rest of the world, continue to underestimate the Heat From Within the planet. Consider, if the sun is the main ingredient here, then why doesn’t this oceanic heating occur all over the planet? Why is this happening exclusively within the Ring Of Fire? Why just the Pacific?
I’ll tell you why. El Nino is the result of the heat from within, escaping along the deep oceanic floor, through plates/vents, where the heat radiates upward/outward, until it reaches the oceanic surface, and then moves into the atmosphere, along with moisture, and there it move along the jet stream, causing the El Nino effect we all know. and when it slows down, La Nina occurs.
If you refuse to see this, fine. I personally don’t care. That’s your problem. But like Continental Drift, its time will arrive, whether you like it or not. Just remember this and know where you read it first.
G-d Bless!