Guest contribution by Willis Eschenbach
I have already said that I see myself more as a climate activist than a climate skeptic. A skeptic doubts parts of things. A heretic questions the basic assumptions underlying the whole area. My heresy is that I don't think temperature is a linear function of greenhouse gas forcing. I think that temperature is regulated by a variety of "emergent" phenomena. In my last post, Watts Available, I discussed my view of how thunderstorms limit tropical Pacific temperature.
In addition to my underlying heresy, I view the various climate phenomena in ways that some people consider backward or inappropriate. I'm not that interested in how these phenomena work. Instead, I'm much more interested in what they do when they work. I was told this is called a "functional" analysis of a situation, which makes sense – I want to see what function a phenomenon does.
When I do a functional style of analysis, I find that thunderstorms work on exactly the same principle as your household refrigerator. And it also leads to my heretical view of another phenomenon of temperature regulation commonly known as "El Nino".
Let's take a leisurely journey through the work of the El Nino / La Nina interchange and consider what are known as "emergent" phenomena.
Let me first discuss the genesis and class of phenomena known as "emergent". Here are the defining characteristics of emergent phenomena.
- Occurring phenomena often arise very quickly from a so-called “featureless background”. For example, a day in the tropical oceans usually begins on a clear day. The clear air usually lasts until late in the morning, when suddenly, without warning, swollen white cumulus clouds form against the background of the strange blue sky and cover half of the sky. These cumulus clouds are an emergent phenomenon.
- In general, emergent phenomena are not what could be described as naive or obviously predictable before they occur. Suppose you've lived your entire life in a tropical, clear blue morning sky without ever seeing or knowing anything about clouds. There is no way you can look up and say, "You know what? I think a whole series of huge masses of white onions might suddenly appear high up in the sky!" People would call you crazy.
- Next, emergent phenomena are generally not permanent. For example, the tropical cumulus clouds above typically dissolve before daybreak. Emerging phenomena usually have a run-up time, a lifetime, and a dissipation time.
- Occurring phenomena are often, but by no means always, associated with a phase change. For example, the clouds mentioned above are associated with condensation, which is a phase change of water from a vapor in the air to tiny droplets of liquid in the clouds.
- Emerging phenomena are often mobile and wander through the landscape. An excellent example of this type of phenomenon are the well-known "dust devils" that often move in dry, hot landscapes.
- Emerging phenomena affect flow systems that are far from equilibrium.
- As the name suggests, emerging phenomena occur spontaneously when the conditions are right.
- The conditions for this emergence are often threshold-based. Once the threshold is crossed, many individual examples of the phenomenon can emerge quickly. This applies, for example, to the tropical cumulus clouds discussed above. As soon as the morning is warm enough and a local temperature threshold is exceeded, a sky full of cumulus clouds materializes quickly out of nowhere.
- Emerging phenomena are generally not cyclical. They don't repeat or move in predictable ways. Because of this, predictions of the phenomenon known as tropical cyclones have "cones" rather than a single line.
From the smallest to the largest, some of the emerging phenomena that I think work together to regulate global temperature are:
• • Dust devil
• • Rayleigh-Benard circulation of both the atmosphere and the ocean
• • Daily cumulus cloud fields
• • Tropical (convective) thunderstorms
• • Gust lines and other thunderstorm aggregations
• • Tropical cyclones
• • The El Nino / La Nina change covered in this post
• • Ocean-wide circulation shifts such as the Pacific Decadal Oscillation (PDO), the Atlantic Multidecal Oscillation (AMO) and the like.
All of these are thermoregulatory phenomena. When the local temperature exceeds a certain level, they leak out and cool the surface in a variety of ways.
With this discussion of emerging phenomena as a prologue, let's look at what's happening in the Pacific. Here's a movie about monthly sea surface temperatures (SSTs). In particular, note the tongue of cooler water that stretches along the equator at variable distances off the coast of South America.
Figure 1. Month-to-Month Temperature Variations, Reynolds Optimal Interpolated Sea Surface Temperature Dataset. The blue field shows the range "NINO34" from 5 ° N to 5 ° S and from 170 ° W to 120 ° W.
So where are the El Nino and La Nina in all this endless movement? Here is a drawing from NOAA showing normal Pacific conditions.
Figure 2. ORIGINAL CAPTION The map (upper surface) shows the Pacific Ocean from America (brown area, right edge) to Australia (brown area, left edge). The graph shows the sea surface temperature (colors from blue to red for cold to hot), the atmospheric circulation (black arrows), the ocean current (white arrows) and the "thermocline" (blue underground sheet). The thermocline is the bottom of the mixed layer – above the thermocline the ocean is regularly mixed, and there is little mixing below. As a result, the water above the thermocline is warmer, often much warmer than the water below the thermocline.
However, at times the heat accumulates in the Eastern Pacific near America. In this case, both the atmospheric and oceanic circulations change, as shown in Figure 3. The thermocline deepens with warmer water near the coast of America.
Figure 3. El Nino conditions. The surface near America is warmer. The thermocline off the coast of America is deeper.
In the transition from theory to measurement, the sea surface temperature (Figure 4) and the anomaly of the sea surface temperature (seasonal fluctuations removed, Figure 5) during an actual El Nino are shown here.
Figure 4. Actual sea surface temperature during the peak month (November) of the great El Nino from 1997-1998. Note the high water temperature in the blue rectangle that outlines the NINO34 area. The temperature in this area is diagnostic of the condition of the El Nino / La Nina change.
Figure 5. Sea surface temperature anomaly (seasonal variations removed) during the peak month (November) of the Great El Nino 1997-1998. This shows the large build-up of heat along the equator in the Eastern Pacific near America.
After an El Nino state peaks, a strong trade wind blows into Asia. This will blow the warm surface water towards Asia until the thermocline off the coast of America reaches the surface. When the warm water reaches the coast of Asia, it splits in two. One part goes towards the Arctic and the other towards the Antarctic. Here is the NOAA chart showing La Nina's terms and conditions.
Figure 6. Schematic representation of the La Nina state.
And as shown above, an actual La Nina state is shown below. This is the La Nina peak of the same Nino / Nina cycle in Figure 5 that began 12 months earlier in November 1997.
Figure 7. Reynolds Optally Interpolated (OI) sea surface temperature for November 1998.
And here is the temperature anomaly at that time:
Figure 8. SST anomaly (seasonal variations removed) during a La Nina peak.
In Figure 8 above, notice how the trade winds exposed the cooler underground waters throughout the equatorial Pacific. They were exposed because the warm water was pushed westward. You can see above how the warm water, when it hits Asia / Australia, is mostly split in two and moves towards the poles.
Now I've started doing functional analyzes. I don't look what is causing the El Ninos or the La Ninas. I'm not trying to understand the processes. Instead, I look at what they're doing.
When I do that, I see that it is wrong to talk about El Nino and La Nina as separate phenomena. Together they act as the largest pump in the world. They pump trillions of tons of warm equatorial Pacific water. So much water is pumped that the height of the equatorial Pacific sea surface decreases and the effect can be seen in local tide meters.
Figure 9. The Nino / Nina differences as shown by the moored TAU / TRITON buoys along the equator. You look west over the equator in the Pacific from a vantage point somewhere in the Andes in South America. The colored surfaces show TAO / TRITON sea temperatures. The top is the sea surface from 8 ° N to 8 ° S and from 137 ° E to 95 ° W. The shape of the sea surface is determined by TAO / TRITON Dynamic Height data. The wide vertical area is 8 ° S and extends to a depth of 500 meters. The narrower vertical area is 95 ° W. All of this data comes from the TAO / TRITON array of moored ocean buoys in the equatorial Pacific.
So … what happens when warm sea water is transported to the poles? More heat is lost to space. Figure 10 shows how much rising surface radiation reaches space by latitude.
Figure 10. Amount of surface radiation ascending into space, around 1 ° latitude band. These are monthly averages over the entire recording period.
In Figure 10 above, the low point at around 7 ° N is the location of the ITCZ, the intertropical convergence zone. As you move towards either pole, the percentage of surface heat radiation that escapes into space increases instantly and continuously.
Given the way my analysis works, I identify “El Nino” and “La Nina” differently than normally indicated.
Various indices are used to assess El Nino / La Nina conditions. An example of an index is that "El Nino Conditions" are times when the sea surface temperature (SST) anomaly in the NINO34 region (blue box) is more than a certain temperature (often around 1 ° C). Warmer as normal. And “La Nina conditions” are when they have more than one degree cooler than normal in the NINO34 region. (There are other identifications, but they all identify the Nino and Nina conditions separately, and they all set a temperature threshold for the Nino and Nina conditions. Neither do I.)
I don't look at them separately or have set temperatures. This is because I don't see them as separate phenomena.
Contrary to the standard definitions, I identify the Nino / Nina phenomenon as a pump that works together. In this pump, the El Nino is the top of the inlet stroke and the La Nina is the top of the outlet stroke. We can see this activity in a graph of the temperature in the NINO34 region (blue rectangle in the graphs above).
Figure 11. Sea surface temperature in the NINO34 area. Blue sections indicate the times when pumping takes place. Red dots show the El Nino top conditions and blue dots show the La Nina top conditions. Dotted vertical white lines indicate November of each year.
I've highlighted the times of pumping in blue. What I first noticed about them is what the Peruvians noticed about them. This means they all start within a month or so of November, and therefore are often strong around Christmas … hence the name "El Nino" for the boy child.
I noticed another oddity. In all highlighted cases, the duration of the pumping process from the red point above (peak “El Nino”) to the blue point below (peak “La Nina”) is one year plus or minus a month or so. This enables us to distinguish the Nino / Nina pumping action from the normal temperature fluctuations that occur anywhere in nature.
The regular duration of the discharge cycle of ~ 12 months also shows that the two (El Nino and La Nina) do not exist as independent units. Instead, they are closely related to a single larger annual phenomenon.
Now remember that the question in functional analysis is, what is the effect of this single larger combined Nino / Nina phenomenon?
I say that the El Nino / La Nina pump is an emerging phenomenon with a lifespan of 12 months. It occurs when enough heat is built up in the eastern equatorial Pacific. It cools the equatorial Pacific and thus the entire planet
1) Exporting the warm equatorial surface waters up, where the heat is lost to space faster, and through
2) Exposing the cooler subterranean ocean layer that cools the atmosphere.
So the function of the El Nino / La Nina change is to cool the earth through a periodic pumping cycle.
Like many other emerging climate phenomena, it is what I refer to as "self-locking". By this I mean that the Nino / Nina pump creates conditions after the start that it strengthens itself and thus tends to persist.
How it works The strength of the trade winds in the equatorial Pacific is determined by the east-west temperature difference. Now when the pumping starts the east will be cooler and the warm water will pool in the west. This increases the east-west temperature difference, which in turn increases the east-west wind force, which in turn increases the temperature difference, which …
This makes it self-locking and this positive feedback is responsible for the long duration of the phenomenon once initiated. As soon as the Nino / Nina phenomenon begins, it creates its own wind. This allows it to continue running until the cold water is exposed along the equator, as you can see in Figure 8 above.
Predictions and Conclusions
Now any theory like mine is only as good as its predictions. So how can I tell if the Nino / Nina is actually an emergent phenomenon that cools the Pacific off when excess heat builds up?
Well … we could start by observing that the cause of the pumping is the heat build-up in the East Pacific. The form of the phenomenon is obviously temperature limiting (cooling) and thermally threshold-dependent (occurs more frequently when it is warmer).
What I had never figured out before this analysis was how to determine whether the overall Nino / Nina pumping phenomenon was more common or stronger in warmer times, or both, than in cooler times. The problem is we already know that it is triggered by excess heat … but does it increase as the excess heat increases? And how would you measure this increase?
What I realized is that as pumping increases in warmer times, such as the current Reynolds SST record after 1981 with a gradual slight warming of the entire ocean surface, we should see different warming trends in the Pacific.
And what the pattern of major and minor trends should look like is what it looks like after a full pumping cycle – the areas on the way to the Pole should be warmer trends and the Eastern Pacific should be cooler. When the number of Nino / Nina cycles increases, the energy transfer shows up in the trend. The trend should be smaller in the area along the equator where the pump exposes cooler water and the trend should be larger as the pump moves the warm water west and toward the poles.
This is how it went at the end of the great Nino / Nina cycle 1997-1998. I repeat Figure 8 from above to here for comparison.
This is Figure 8 from the top.
And here are the ocean surface trends over a 36-year period during which, as the following figure shows, there has been a slight SST warming (0.10 ° C per decade).
Figure 12. Decadal trends in sea surface temperature.
My conclusion, from the marked similarity between these last two diagrams, is that the prediction from my theory is correct – the Nino / Nina pump is indeed a temperature regulating emergent phenomenon that counteracts any increase in the overall tropical Pacific temperature.
The first rain came here yesterday after a long dry "fiery but mostly peaceful" forest fire season here … the forest smell of growth, green life and decay is particularly strong tonight and reminds me of the endless cycles of creation and destruction.
My best regards to all,
Post Scriptum: When making a comment, please quote the exact words you are discussing. This helps avoid the endless misunderstandings that plague the internet. For more information on how to show I'm wrong, please see my "Disagree" post.