Will There Be A 2018/19 El Niño?

By Bob Tisdale – Re-Blogged From http://www.WattsUpWithThat.com

Looks like one may be forming right now.

Judith Curry published the post ENSO forecast for 2018 yesterday. On the thread (here) I asked and stated:

Judith, the question that needs answering: Are weather conditions right for a series of westerly wind bursts in the western tropical Pacific? Without westerly wind bursts to initiate downwelling Kelvin waves, there will be no El Niño.

So this morning I checked with the NOAA GODAS website, and, yes, there have been westerly wind bursts this year. See the hovmoller plot of the “Surface zonal wind stress anomaly” from the GODAS Pentad Anomaly Products webpage (my Figure 1 below).

Figure 1

Then it was time to check the subsurface temperature anomalies for the equatorial Pacific. And they can be found at the NOAA CDC webpage here. See animation 1 below. A downwelling Kelvin wave is already making its way across the equatorial Pacific.

Animation 1

So to answer the title question, it obviously appears the initial phases of the processes that initiate an El Niño are already in progress.

Will an El Niño in 2018/19 be strong enough to permanently raise global sea surface temperatures?

Only time will tell. And if you’re wondering how a strong El Niño can (and does) raise global sea surface temperatures permanently, then you obviously haven’t read my ebook Dad, Why Are You A Global Warming Denier? – A Short Story That’s Right for the Times, which is available in Kindle ebook and in paperback editions. In that book, I’ve explained how a strong El Niño can (and does) raise global sea surface temperatures permanently so simply that an eight-year-old can understand it. How do I know? In real life, I explained it to an eight year old, and he understood, no problem. BTW, I have not discussed, and have no intention of discussing, that very simple aspect of strong El Niños in a blog post.

Ciao!

CONTINUE READING –>

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13 thoughts on “Will There Be A 2018/19 El Niño?

  1. The global energy equation is very simple.

    Δ(H&W) ≈ Ein – Eout

    The change in heat energy content of the planet – and the work done in melting ice or vaporising water – is approximately equal to energy in less energy out. And you have to ask how the Pacific state changes energy out.

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    • “…ask how the Pacific state changes energy out.” I’d say variability rather than change. At that latitude, the prevailing winds are out of the east, causing the Pacific there to move east to west. Water ‘piles up’ on the west (the Pacific Warm Pool) a few feet higher than in the east.

      The Warm Pool heats from the sun, and the water stays where it is, so the warmth expands to depth. At some point (several years), warm water at depth, not being kept in place by the prevailing winds, starts traveling east, rising slowly as it moves. It can reach the surface thousands of miles to the east. When it surfaces, it can warm the air over it, causing the air to rise, ‘sucking’ air in from the west. This may cause the prevailing easterlies to turn to westerlies temporarily, and an El Nino is born. The El Nino may last for 4-6 months, and sometimes reappears the following year if the Warm Pool hasn’t been exhausted.

      Eventually, the normal east to west air flow returns, pushing the Pacific back toward the west with it. This sloshing back toward the Pacific Warm Pool may cause some of the warmer water to ‘overflow’ going into the Indian Ocean and into the more northerly Pacific. This east to west ocean flow reaction to the El Nino is called a La Nina, which progresses much more slowly than the El Nino. The heat/water flow of El Nino may be a single season, while the La Nina (if it occurs) would have its effects over several years – definitely not a symmetric pattern.

      These recurring, natural cycles affect global weather patterns for thousands of miles beyond the Pacific – into the Arctic, Atlantic, and Indian Oceans. While these cycles tend to be a few years apart, there also is a roughly 60 cycle during which El Ninos may be more likely to occur, alternating with a more less likely time period.

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    • From what I understand, ENSO, (El Nino Southern Oscillation) is an east/west movement driven by the sun. If anything, I would expect that ENSO affects AAO rather than the other way around. (I likely need to research this some more.)

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      • The meridional patterns of the polar annular models spin up the south and north Pacific gyres causing more upwelling that in turn sets up wind and current feedbacks across the Pacific. This is the origin of both the PDO and ENSO.

        Multi-decadal variability in the Pacific is defined as the Interdecadal Pacific Oscillation (e.g. Folland et al,2002, Meinke et al, 2005, Parker et al, 2007, Power et al, 1999). The latest Pacific Ocean climate shift in 1998/2001 is linked to increased flow in the north (Di Lorenzo et al, 2008) and the south (Roemmich et al, 2007, Qiu, Bo et al 2006)Pacific Ocean gyres. Roemmich et al (2007) suggest that mid-latitude gyres in all of the oceans are influenced by decadal variability in the Southern and Northern Annular Modes (SAM and NAM respectively) as wind driven currents in baroclinic oceans (Sverdrup, 1947).

        There is a growing literature on the potential for stratospheric influences on climate (e.g. Matthes et al 2006, Gray et al 2010, Lockwood et al 2010, Scaife et al 2012) due to warming of stratospheric ozone by solar UV emissions. Models incorporating stratospheric layers – despite differing greatly in their formulation of fundamental processes such as atmosphere-ocean coupling, clouds or gravity wave drag – show consistent responses in the troposphere. Top down modulation of SAM and NAM by solar UV has the potential to explain otherwise little understood variability at decadal to much longer scales in ENSO.

        This is an idea consistent with the stochastically forced model of ENSO – as opposed to the delayed oscillator model. The latter is described in terms of Rossby and Kelvin waves. These exist but are not fundamental to the ENSO dynamic.

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      • Much of what we’re saying is the same, except for cause & effect. In reality, while there are many theories, nobody really knows why El Ninos start.

        I find NASAs video leaves questions. They say turbulence causes the west to east airflow at times. But turbulence from where? With the ocean having a huge thermal mass compared to the atmosphere, I expect that the west to east flow is more likely to be caused by the ocean. Also, NASA for some reason doesn’t mention water at depth moving west to east – recently referred to as ‘The Blob.’ I think that when the Blob surfaces, it warms the air over it, which is what causes the west to east winds (air over the east rises allowing the air from the west to move in). What causes the Blob? I expect it’s partly due to the surface water movement from east to west, causing the higher western depth and downwelling, and then from west to east at depth.

        Is it associated with upwelling in Peru? Definitely. But, the upwelling is an effect, not a cause. Coriolis? I expect that’s a cause – but the cause & effect still are not known definitively, regardless ofhow many MODELS that NASA puts together. (A model is just another theory.)

        BTW< thanks for the feedback.

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  2. It is not a NASA video at all. Your ‘blob’ is a reflecting Kelvin wave. Atmospheric turbulence can be caused by the Madden-Julian Oscillation, a weakening of upwelling or any of a number of factors in a complex and dynamic system. But the origin of ENSO is undoubtedly upwelling on the eastern margin of the Pacific. The cause of increased upwelling is spinning up of the south Pacific gyre. Upwelling creates zones of low surface pressure in the west and high in the east that create the geopotential gradient across the Pacific. It is a baroclinic phenomenon influencing the disposition of the sun warmed surface layer – and not thermally driven as such.

    The equatorial Kelvin wave resulting when trade winds falter is the emerging El Nino – it is very different to the reflecting and submerging Kelvin wave that is at the core of the delayed oscillator model of ENSO. Model in this sense btw is simply a conceptual framework – a paradigm – for understanding process. The size and duration of an El Nino depends on the height anomaly in the western Pacific – before the trade winds falter and surface water flows eastward. Recharge in the western Pacific is simply not there yet.

    A paradigm in the scientific sense is a theory that explains observations. A new science paradigm is one that better explains data. As far as theories are concerned we at least an ocean apart. The key to ENSO is what is happening in the eastern Pacific.

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    • The Blob is NOT a Kelvin Wave. A Kelvin Wave is a surface phenomenon, caused by wind direction. So for example, when an El Nino starts, the prevailing east to west winds shift to a west to east causing an ocean west to east Kelvin Wave. The Blob is well below the surface, so it cannot be caused by wind direction. Also, the Blob comes before an El Nino and is an indicator that an El Nino may be imminent.

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      • The equatorial trade winds are north-east and south-east in the NH and SH respectively. In the open ocean on the equator they result in oceanic upwelling.

        When currents hit a coastline it results in downwelling.

        It is a process in the deepening thermocline in the western Pacific in La Nina and is almost purely inertia in a downwelling Kelvin wave. The idiotically named blob of popular blogging. The depth of the thermocline and the height of water mounded in the western Pacific is indeed indicative of the energy available to an emerging El Nino – and the likelihood of it being unleashed.

        The equatorial Kelvin wave is the result of warm water mounded against Australia and Indonesia sloshing eastward to crash against the Americas and dissipate north and south in coastal Kelvin waves. Then the whole thing starts again when the thermocline is again shallow enough to permit upwelling. Cold water rises resulting in a high surface pressure cell in the east with positive feedbacks and renewed Walker circulation. This is the so-called ENSO normal.

        So yes it is a Kelvin wave Virginia.

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  3. “Judith, the question that needs answering: Are weather conditions right for a series of westerly wind bursts in the western tropical Pacific? Without westerly wind bursts to initiate downwelling Kelvin waves, there will be no El Niño.”

    Bob’s error is to imagine that downwelling Kelvin waves need westerlies to be initiated. What wind anomalies initiate is a sloshing of mounded surface water eastward – the equatorial Kelvin wave – that is almost purely a gravity effect.

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  4. Actually, no. Just down from the quote you gave, there is a subsurface temperature animation, which clearly shows a Blob (stupid name or not, see the animation) forming. Where these Blobs surface, and how much warm water they contain, affects the amount of heat they can release in the more eastern Pacific. Their heat cause the air to rise above them, drawing in air from the west, creating the wind anomaly you talk about. Again, it’s chicken & egg stuff. The natural downwelling at the western pacific margin may be the cause of the Blob moving east at depth, but it’s the Blob surfacing that changes the system temporarily to El Nino. The reversed wind pattern allows gravity to set up the equatorial Kelvin Wave.

    Please accept that we both are saying the same thing, rather than trying to make somebody wrong. We both say that east to west prevailing winds cause a piling up of warmer water in the west. Part of this water downwells setting up the sloped thermocline that you’ve talked about. Both of us say that sometimes the prevailing winds shift to west to east, allowing the warm water to slosh eastward at surface. The only difference is that Bob Tisdale shows the animated data of the Blob, which closes the loop by causing the wind shift to west to east.

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