ENSO forecast for 2018

by Jim Johnstone and Judith Curry

Attempting to breach the ENSO springtime  ‘predictability barrier.’

The springtime predictability barrier in ENSO predictions (Webster and  Yang 1992) arises from stochastic processes occurring in the tropical Pacific that are tied to the annual cycle. As a result, forecast initialized prior to May (and in some years, as late as July) have shown little skill in ENSO prediction from late summer to the end of the year.

Recent advances in global seasonal forecast models appear to be breaching the predictability barrier to some extent. We have conducted a climate dynamics analysis seeking to identify the sources of this extended range ENSO predictability. We have identified DJF precursor signals in upper tropospheric and stratospheric anomalies at high latitudes of both hemispheres, consistent with research showing important extratropical forcing of surface wind anomalies and SST responses in the equatorial and off-equatorial Pacific.

So, how might all this actually translate into a useful forecast for 2018 ENSO conditions?  My company Climate Forecast Applications Network (CFAN) has issued our first long-range ENSO forecast. I look forward to your feedback.

The forecast report can be downloaded [ENSO 2018 forecast].

This forecast was motivated by our seasonal forecast for Atlantic hurricanes, which can be dowloaded here [Apr Fcst 2018 hurricane].

Introduction

CFAN’s early season ENSO forecast is motivated by preparing our seasonal forecast for Atlantic hurricane activity. ENSO forecasts made in spring have traditionally had very low skill owing to the ENSO ‘spring predictability barrier.’

Currently, an ongoing La Niña event is reflected by a negative sea surface temperature (SST) anomaly (-0.7 °C) in the equatorial east-central Pacific Niño 3.4 region. The present La Niña event, the most recent since 2014, was largely established by fall 2017.

Observers have long noted that cool winter La Niña events often persist or grow into the following winter, in contrast to El Niño events that more frequently undergo rapid spring-summer reversals. From 1980 to 2017, 11 of 14 La Niña winters were repeated by La Niña conditions in the subsequent December. However, reversals have become more frequent in recent years, with all three La Niña to El Niño transitions since 1980 observed in 2006, 2009 and 2014.

CFAN’s ENSO forecast analysis is guided by the ECMWF SEAS5 seasonal forecast system and a newly developed statistical forecast scheme based on global climate dynamics analysis.

ENSO forecasts from global models

The IRI/CPC plume of model ENSO predictions from mid-March 2018 is shown in Figure 1. The average for all models is 0.4 for OND and 0.5 for NDJ, with 44% and 48% probabilities, respectively, for El Niño.

Figure 1. https://iri.columbia.edu/our-expertise/climate/forecasts/enso/current/?enso_tab=enso-sst_table

The latest forecast from NOAA CPC (4/1/18) is shown below, which predicts the highest probability to be neutral values through the end of 2018.

Figure 2. http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/lanina/enso_evolution-status-fcsts-web.pdf

The latest forecast from ECMWF (initialized March 1) is shown in Figure 3, for Niño3.4 and Niño4 (indicative of Modoki). ECMWF predicts a transition towards El Niño conditions by autumn, with an average September prediction of 0.75C. There is no evidence of a Modoki (bottom figure, Nino 4).

Figure 3: CFAN’s analysis of ENSO forecasts from ECMWF SEAS5, initialized 4/1/18. Nino3.4 (top); Nino4 Modoki (bottom).

CFAN’s analysis of the ENSO hindcast skill of the ECMWF SEAS5 shows a correlation coefficient of 0.73 for Niño3.4 forecasts initialized in April for the next seven months (October).

Figure 4: Evaluation of the predictability of the Niño 3.4 index: correlation of observed versus predicted) from ECMWF SEAS5 as a function of initial month and lead-time. From Hirata, Toma and Webster, 2018: Updated quantification of ENSO influence on the U.S. surface climate.

ECMWF SEAS5 represents a substantial improvement relative to SEAS4:

Figure 4a: Evaluation of the predictability of the Niño 3.4 index: correlation of observed versus predicted) from ECMWF SEAS4 as a function of initial month and lead-time.

Statistical ENSO forecast model

Figure 5 illustrates the recent ENSO history as depicted by monthly Niño 3.4 anomalies from 1980 to February 2018. Highlighted are the past 14 La Niña Februaries (< -0.5°C), and anomalies in the following Decembers. Since 1980, neutral conditions (-0.5 to +0.5) follow La Niñas about 50% of the time, and La Nina and El Nino about 25% each.

Figure 5. Time series of the monthly Niño 3.4 SST index (5°N-5°S, 170°-120°W), with cool February La Niña anomalies (<-0.5°C) highlighted by blue markers and subsequent December anomalies marked in black.

Fig. 6A illustrates the same data separately for months surrounding each February event, and Fig. 6B shows Niño 3.4 anomalies with respect to February values. From cool initial February conditions, La Niña nearly always moderates in early spring (Fig. 6A), rising from a winter minimum toward a warmer, more neutral ENSO state by April. From April onward, however, a variety of trajectories may develop, leading either to continued warming and transition to El Niño by December, or alternatively, persistence or regrowth of La Niña conditions. Figure 6. Seasonal Niño 3.4 SST anomalies surrounding February La Niña conditions. A. Time series of monthly anomalies from the prior July through December, plotted separately for each year. Changes culminating in next-December El Niño conditions (>0°C) are plotted in red; weak La Niña conditions (defined here as -0.5 to 0°C) in light blue, and La Niña conditions (< 0.5°C) in dark blue. 2017-18 values are plotted in black triangles through February 2018 (-1.0°C). B. Monthly values relative to February.

Our model for the December 2018 Niño 3.4 forecast was developed by comparing December-February (DJF 2017/18) atmospheric anomalies with patterns in previous La Niña winters that most successfully predict next December Niño 3.4 conditions. Atmospheric data comes from the NCEP-NCAR Reanalysis. Predictor indices are systematically generated from different atmospheric variables over a range of heights, and latitude bands, using different weighting approaches for index construction. The indices are evaluated in leave-one-out mode, and the forecast skill is measured for each. This approach is designed to limit predictors to only those that show historical predictive skill in experiments that emulate the current forecast process.

A subset of three forecast models was selected to produce the overall Niño 3.4 forecast, with additional models used to estimate uncertainties. The most skillful predictors come from Northern Hemisphere DJF zonal (U) wind tendencies in the lower stratosphere, in a pattern that captures weak westerly flow over the Arctic and contrasting strong flow above the subtropical eastern Pacific. Current expression of such conditions in DJF 2017 contribute to expectations of neutral or El Niño conditions by December 2018. Similar indications are given by anomalous DJF convergence in the upper troposphere above Antarctica, as well as patterns of meridional (V) winds in similar areas of the Southern Hemisphere. The skill of these predictors reflect the importance of extratropical forcing of surface wind anomalies and SST responses in the equatorial and off-equatorial Pacific.

Historical forecasts from all three models are compared with observed Niño 3.4 values in Fig. 7. Models are based on data from 1980 through 2017, but show particularly good skill for the 2014 reversal to a weak (+0.6°C) December El Niño, comparable to the magnitude of the event projected for 2018. Individual models produce December 2018 Niño 3.4 estimates of +0.4, +0.5, and +0.9°C, averaging +0.6°C.

Figure 7. December Niño 3.4 SST projections from three forecast models are based on linear regressions on previous December-February (DJF) atmospheric circulation indices. Points are plotted in relation to December Niño 3.4 forecast values (x-axis) produced from previous DJF atmospheric precursors, and observed December values. Models are based on atmospheric precursors identified in the Arctic/North Pacific (red) and the Antarctic/Southern Hemisphere (green and blue) that show greatest skill in historical forecast experiments (r = 0.7 to 0.8). Individual models correctly estimated the sign of December Niño 3.4 anomalies in 37 of 42 cases (88%). December 2018 Niño 3.4 SST estimates of 0.4, 0.4 and 0.9°C (circles) are based on the recent DJF expression of skillful atmospheric indicators.

Atmosphere-ocean changes during La Niña-to-El Niño transitions are illustrated in composites of sea-level pressure (SLP) and SST anomalies for 2006, 2009 and 2014 (Fig. 8). Initial SST anomalies in February (Fig. 8A) feature La Niña’s defining signature pattern of cool water in the east-central equatorial Pacific. High SLP over the eastern tropical Pacific contrasts with low SLP over the Indo-Pacific warm pool, characteristic of an intensified Walker circulation and strong low-level easterly winds that maintain cool La Niña surface conditions in the east.

Figure 8. Composite maps of SLP, SST and wind anomalies and changes leading from February La Niña conditions to El Niño in December (2006, 2009, 2014). A. February La Niña SST composite. B. February La Niña SLP composite. C, D. April-June (AMJ) SST and SLP anomalies (differences from February). D,E. July-September (JAS) anomaly differences from February. F,G. October-December (OND) anomaly differences from February. Vectors reflect low-level wind anomalies at 925 hPa.

Composite SST anomalies (Figs. 8D,8E,8G) and SLP (Figs.8D,8F,8H) reflect developing ocean-atmosphere changes during transitions from February La Niña to December El Niño conditions. Maps reflect anomalies with respect to February values during spring (April-July, AMJ), Summer (July-September, JAS) and fall (September-November, SON) periods. Eastern Pacific surface warming begins in spring, and once established, warm conditions are maintained through December. Throughout much of the calendar year, negative SLP anomalies persist over the North Pacific, while associated cyclonic circulation anomalies tend to weaken off-equatorial North Pacific trade winds, a recognized contributing mechanism to El Niño development. From summer onward, cyclonic North Pacific winds also generate warming the northeast Pacific in conjunction with equatorial SST increases. During spring and summer, transitions to El Niño include coherent SLP anomalies over both polar caps, patterns broadly consistent with the polar atmospheric precursors identified by our forecast models.

Atmospheric precursors of El Niño transitions likely reflect contributions from multiple large-scale mechanisms, rather than a single, continuous process. During each recent transition (2006, 2009, and 2014), a similar two-stage warming pattern (Fig. 9A) is characterized by moderate SST increases in spring (April-May), but minimal changes in a June-September summer window that is followed by final surge of strong warming in October-November. Composite SST changes in spring and fall are also somewhat different in spatial structure. Early warming (Fig. 9B) develops over broad areas of the tropical Pacific from South America to Australia, but more concentrated and intense central Pacific warming is seen in fall.

Figure 9. Seasonal ocean-atmosphere changes during La Niña-to-El Niño transitions in 2006, 2009 and 2014. A. Monthly changes in Niño 3.4 SST. B. Composite SST changes during April-May of all three years. White hatching reflects statistically significant (p < 0.05) anomalies, based on observations from both months and all three years. C. Composite April-May anomalies of 1000 hPa (near-surface) April-May zonal winds. Red shading (westerly anomalies) in the tropical Pacific reflect weak easterly flow conducive to observed eastern Pacific warming and growth of El Niño. D. Composite October-November SST changes. E. Composite October-November zonal winds.

Equatorial Pacific warming is typically produced by anomalous westerly winds that reflect weakness in the mean easterly surface flow. In the April-May window of initial spring warming, westerly wind anomalies appear over the central Pacific (Fig. 9C) in conjunction with significant wind anomalies of both signs throughout much of the tropics as well as the Arctic. Fall warming in October-November (Fig. 9D) is similarly traceable to equatorial westerly wind anomalies (Fig. 9E) that extend over much of the tropical and subtropical Pacific and the globe, including both polar regions.

Our current forecast approach, by estimating the December ENSO state, implicitly accounts for all contributing processes during the calendar year.

Forecast summary

CFAN’s near-term prediction of ENSO is for a transition to neutral conditions over summer. Our extended-range statistical model predicts an average value of Nino3.4 0.6°C for December 2018. The forecast probabilities are:

El Nino        > 0.5          40%
Neutral +   0 to +0.5    46%
Neutral –   -.05 to 0      13%
La Nina       < -0.5         0%

In communicating these forecasts it is difficult to strike appropriate balance between actual probabilities from the objective forecast model, versus confidence in the forecast. IPCC has this same problem. So I don’t have 100% confidence in 0% probability of La Nina.

CFAN’s model for extended-range ENSO forecast is based on a new approach, and hence there is not an actual forecast track record for this methodology. Confidence in our prediction for 2018 can be derived from our hindcast predictions back to 1980 and the physical plausibility of the model predictors based on our predictability analysis.

It remains to be seen how successful we will be in breaching the ENSO springtime ‘predictability barrier.’

Historical phase-locked El Nino episodes

While we are on the subject of ENSO predictions, here is a really interesting paper:

Historical phase-locked ENSO state

David Douglass, Robert Knox, et al.

Abstract. Using a newly reported Pacific sea surface temperature data set, we extend a prior study that assigned El Niño episodes to distinct sequences. Within these sequences the episodes are phase-locked to subharmonics of the annual solar irradiance cycle having two- or three-year periodicity. There are 40 El Niño episodes occurring since 1872, each found within one of eighteen such sequences. Our list includes all prev- iously reported events. Three El Niño episodes have already been observed in boreal winters of 2009, 2012 and 2015, illustrating a sequence of 3-year intervals that began in 2008. If the climate system remains in this state, the next El Niño is likely to occur in boreal winter of 2018.

Douglass, D.H., Knox, R.S., Curtis, S., Giese, B.S. and Ray, S. (2017) Historical Phase-Locked El Niño Episodes. Atmospheric and Climate Scien- ces, 7, 48-64. http://dx.doi.org/10.4236/acs.2017.71005

115 responses to “ENSO forecast for 2018

  1. ENSO forecasting is just not up to the task. Here is the latest fiasco from ECMWF system. It was not the first:

    https://i.imgur.com/coRfZyA.png

    They also predicted a 2014 El Niño that failed to materialized. And they are not the only ones. I have followed IRI CPC model ensemble (the one from figure 1) for a couple of years and there is no skill in it. If you select the top performers for a 9 month period they can easily be the worst performers in the next 9 months.

    Then we have a different type of ENSO forecasting:

    Title:
    Predicting the La Niña of 2020-21: Termination of Solar Cycles and Correlated Variance in Solar and Atmospheric Variability
    Authors:
    Leamon, R. J.; McIntosh, S. W.
    Affiliation:
    AA(University of Maryland College Park, College Park, MD, United States Code 672, NASA Goddard Space Flight Center, Greenbelt, MD, United States robert.j.leamon@nasa.gov), AB(High Altitude Observatory, Boulder, CO, United States mscott@ucar.edu)
    Publication:
    American Geophysical Union, Fall Meeting 2017, abstract #SH42A-05
    Publication Date:
    12/2017
    Abstract
    Establishing a solid physical connection between solar and tropospheric variability has posed a considerable challenge across the spectrum of Earth-system science. Over the past few years a new picture to describe solar variability has developed, based on observing, understanding and tracing the progression, interaction and intrinsic variability of the magnetized activity bands that belong to the Sun’s 22-year magnetic activity cycle. The intra- and extra-hemispheric interaction of these magnetic bands appear to explain the occurrence of decadal scale variability that primarily manifests itself in the sunspot cycle. However, on timescales of ten months or so, those bands posses their own internal variability with an amplitude of the same order of magnitude as the decadal scale. The latter have been tied to the existence of magnetized Rossby waves in the solar convection zone that result in surges of magnetic flux emergence that correspondingly modulate our star’s radiative and particulate output. One of the most important events in the progression of these bands is their (apparent) termination at the solar equator that signals a global increase in magnetic flux emergence that becomes the new solar cycle. We look at the particulate and radiative implications of these termination points, their temporal recurrence and signature, from the Sun to the Earth, and show the correlated signature of solar cycle termination events and major oceanic oscillations that extend back many decades. A combined one-two punch of reduced particulate forcing and increased radiative forcing that result from the termination of one solar cycle and rapid blossoming of another correlates strongly with a shift from El Niño to La Niña conditions in the Pacific Ocean. This shift does not occur at solar minima, nor solar maxima, but at a particular, non-periodic, time in between. The failure to identify these termination points, and their relative irregularity, have inhibited a correlation to be observed and physical processes to be studied. This result potentially opens the door to a broader understanding of solar variability on our planet and its weather. Ongoing tracking of solar magnetic band migration indicates that Cycle 24 will terminate in the 2020 timeframe and thus we may expect to see an attendant shift to La Niña conditions at that time.

    Link

    I am waiting for the article. It might look fringe, but McIntosh and Leamon are two well respected astrophysicists that have published lots of well cited articles on solar physics and have put forward a very interesting hypothesis for the generation of the 11-year solar cycle from the 22-year solar magnetic cycle that explains when, how and how many sunspots are generated. See for example:
    McIntosh, S. W., Wang, X., Leamon, R. J., Davey, A. R., Howe, R., Krista, L. D., … & Pesnell, W. D. (2014). Deciphering solar magnetic activity. I. On the relationship between the sunspot cycle and the evolution of small magnetic features. The Astrophysical Journal, 792(1), 12.
    http://iopscience.iop.org/article/10.1088/0004-637X/792/1/12/meta

    If they are correct, we should see a shift to La Niña conditions starting in 2020.

    • ECMWF has a new seasonal forecast model effective Oct 2015. See figures 4 and 4a for the improvements in the new model relative to the old.

      • Judith,

        I remain skeptical about the ability to predict ENSO. The link in your figure 4 goes to an abstract that only talks about system 4. Was there a January 2017 forecast from system 5 that can be evaluated?. If it was substantially better than the rest you might have a point.

        As I said, I followed IRI CPC ENSO forecast for quite a long time. I made this figure from their Feb 2017 prediction, adding their month by month observation (black dot) from their monthly pictures.

        https://i.imgur.com/dFrvrDE.png

        Last October I gave up. It is useless. By September the spread of the 23 models goes from -0.7 to +1.6 so at least one has to be close to the observation only from chance, but not a single one of the 23 models came close to the evolution of the observations. The IRI CPC plume has absolutely no predicting power. 23 nearly useless models.

        Even Pukite, aka WebHubTelescope, an obnoxious past commenter of Climate.Etc that made a big deal about his model based on Length-of-Day has been getting everything backwards so far.

        https://i.imgur.com/SpCohpX.png

        No weak El Niño in 2017 and no weak La Niña in 2018. However his strong La Niña of 2019 more or less coincides with Leamon & McIntosh La Niña prediction based on solar activity for 2020. We will have to wait and see.

        So far I have not seen anything that can tell me that ENSO can be successfully predicted.

      • Hirata et al. are all employees of my company. We published Fig 4a somewhere, not sure where. Fig 4 is new. The SEAS5 ENSO forecast initialized in Feb initialized on Feb 1 at around -0.4, predicted an average of 0 for Apr 1. It has been running a bit high

      • Javier: I remain skeptical about the ability to predict ENSO.

        Me too. BUT CFAN here presents an earnest well-informed attempt, and the proof will be available soon enough.

      • Javier: Even Pukite, aka WebHubTelescope, an obnoxious past commenter of Climate.Etc that made a big deal about his model based on Length-of-Day has been getting everything backwards so far.

        How does that graph show him getting “everything” “backwards”.

      • Matthew,
        How does that graph show him getting “everything” “backwards”.
        The hindcast is good. That’s why I keep a “wait and see” approach. After all my opinion is that LOD is a climate integrator. But models always have to hindcast well. It is the forecast that counts.

        https://i0.wp.com/imageshack.com/a/img924/9074/5VVywf.png

      • ENSO has economic impacts, good and bad, all over the place, so modelers are never going to give up on trying to perfect their ENSO forecast models. CFAN will reap an economic reward if an El Niño forms in December 2018. If they can repeat successful forecasting, that reward will grow immensely.

        If one dismisses them as abject failures forever, well, they won’t be there when somebody finally pulls it off. One can assume ENSO forecasters drag they beaten butts back to the workshop and hone their models for the next go around, so I don’t see much point in talking too much about past failures.

      • Javier: It is the forecast that counts.

        It looks to me like he did well after the training period. Where did he get “everything” “backwards”?

      • This is a commercial, computerized curve fitting program – but if you note the numbers on the axis – it ain’t SOI.

        LOD varies with the ENSO state.

        https://arstechnica.com/science/2014/05/how-el-nino-temporarily-slowa-the-earths-rotation/

        But this just makes it a problem of predicting LOD rather than ENSO. Like all of Pukite’s stuff – it is utterly stupid.

      • Robert I Ellison: This is a commercial, computerized curve fitting program – but if you note the numbers on the axis – it ain’t SOI.

        He calls it SOI. If he takes comments, let’s ask him if he simply rescaled it.

        Whatever it is, does it look to you like he got “everything” “backwards” after the training period.

      • Matthew,

        It looks to me like he did well after the training period. Where did he get “everything” “backwards”?

        You are a trusting soul. A skeptic should doubt even peer-reviewed claims, so when dealing with non-peer-reviewed claims nothing should be taken at face value. It only takes 10 minutes to download and plot 3-period averaged SOI from:
        https://www.ncdc.noaa.gov/teleconnections/enso/indicators/soi/data.csv

        It becomes clear that the fit is not as good as claimed. Pukite has done something to official SOI data, or used a different SOI data, or…

        https://i.imgur.com/8tv3ayO.png

        In any case, as always, what counts is not the period presented, or hindcasted, but the period forecasted in the future (in red after 2016). In this case it is clear that the La Niña of late 2017-early 2018 is missing.

      • Robert I Ellison: Like all of Pukite’s stuff – it is utterly stupid.

        As WebHubTelescope he was an abrasive and insulting commentator. I criticised some of his work, including his critical comment on “Thermodynamics, Kinetics, and Microphysics of Clouds”. But I called his models “live” and encouraged him to publish his predictions of ENSO. He has a good series of posts beginning here:

        http://contextearth.com/wp-content/uploads/2016/05/SOIM-document.pdf.

        and summarized here:

        https://www.essoar.org/doi/pdf/10.1002/essoar.b1c62a3df907a1fa.b18572c23dc245c9.1

        All downloadable.

        It looks to me like he has made progress since he was a regular here.

        The test of “curve fitting” is in the fit to future out-of-sample data. For those models, the data will be arriving soon. The published fits to beyond-training-set data are encouraging.

      • As I explained – LOD varies with ENSO but is not any more predictable. As for reading any more of this nonsense – is it a cold day in hell?

      • Javier: A skeptic should doubt even peer-reviewed claims, so when dealing with non-peer-reviewed claims nothing should be taken at face value.

        No one is taking anything “at face value”. I downloaded his predictions so I’ll have them available when the out of sample data become available in the future. If, as is common, he responds to future misfits by re-estimating his parameters and recalculating his “predictions”, it will be public knowledge that his actual forecast was in error.

        I think that contrasts nicely with RIE’s “forecast” that the decade 2018-2028 will ring in a regime change that is totally unspecified: what measures will show it? Will they be higher, lower, or more oscillatory than before? Will they be mostly land or mostly sea? Northern or southern hemisphere?

        In the meantime, I can not find anywhere that your claim that Paul Pukite has gotten “everything” “backwards” since the end of the training data is justified. He got at least 1 peak basically correct in the out of sample data. His fits are “not as good as he claims” I can see, but not that he has gotten “everything” “backwards”.

    • Good read.

      NOAA has an ENSO blog, and they maintain a site with historic ENSO events for the last ~50 years.

      December 2017 La Niña update: Double, double

      Our second La Niña year in a row is in full swing now, and is forecast to last through the winter. In November, the average surface water temperature in the Niño3.4 region of the central Pacific Ocean was about 1.0°C cooler than the long-term average. A “double-dip” La Niña is not uncommon …

      https://i.imgur.com/tjF6Cml.png

      Two in a row.

    • Ulric Lyons

      There should be a major El Nino episode around one year past the next sunspot minimum, like the 1997-1998 and 2009-2010 episodes.
      Solar wind speed:
      https://snag.gy/n9IuHy.jpg

    • It depends on what you look at. ENSO hasn’t been doing much lately – a very minor cool spike, a short lived El Niño and the still very modest current La Niña.

      https://www.climate.gov/sites/default/files/SummerForecast_large.png

      Going beyond the spring predictability barrier with statistical models has had nil success and dynamic models have very low skill.

      https://www.climate.gov/sites/default/files/SummerForecast_large.png

      It is not clear what fig 4 means – and I can’t find the Hirata et al paper – just an abstract.

    • https://i.imgur.com/dxxMZ5d.png

      Consequently, NOAA scientists blog about the 2016 La Niña and the 2017 La Niña being back-to-back La Niña events.

      • Hm.
        You posted overlapping sets of 3 months for 3 months in a row totaling a 5 month period which is a little different to 5 overlapping 3 month periods which would actually add up a 7 month period as it is worded by NOAA above. Not your fault. Sloppy wording by NOAA which should have said at least 3 overlapping 3 month periods in order to be counted as a full blown episode in the historical record.
        They will probably read this and change their faulty wording. Congratulations JCH.

    • “Why do I believe that the MEI is better for monitoring ENSO than the SOI or various SST indices? In brief, the MEI integrates more information than other indices, it reflects the nature of the coupled ocean-atmosphere system better than either component, and it is less vulnerable to occasional data glitches in the monthly update cycles. Now, if you are interested in ENSO impacts in a very specific part of the world, I would suggest that you obtain other ENSO indices as well and establish which one best fits your needs. For instance, in Australia, Darwin sea level pressure and/or the SOI may be more appropriate than the MEI. My claim here is that the MEI does a better job than other indices for the overall monitoring of the ENSO phenomenon, including, for instance, world-wide correlations with surface temperatures and rainfall.” Claus Wolter

      What happens after a short lived El Niño?

      https://www.esrl.noaa.gov/psd/enso/mei/comp.png

      “Looking at the nearest 12 rankings (+6/-6) in this season, and excluding the two cases that showed a three-month rise of 0.4 or more, we end up with the following ten ‘analogues’: 1950, 51, 62, 63, 67, 68, 97, 99, 01, and 09 (three of these were flagged as an analogue last month: 63, 68, and 09). Subsequently, five of these analogues transitioned to El Niño conditions at some point during the same calendar year (within two months in 1997 compared to nine months in 1968, while 1951, 63, and 09 fall in between). In contrast, four years (1950, 62, 67, and 99) remained more or less in their La Niña state through the remainder of the year, and only 2001 eased into an ENSO-neutral state. Not much to glean from historical analogues, except that ENSO-neutral is least likely later this year.”

      Hmmmm….

  2. There is a glaringly obvious 42 month cycle in the satellite lower troposphere temperature data and the rate of change of atmospheric CO2 concentration. This is probably the driving factor for the El Nino event possibly caused by the periodic changes in the configuration of the Sun, Moon and planets relative to the Earth. See:
    https://www.climateauditor.com
    for a detailed analysis.

  3. Charles May

    I analyze all four Nino regions. In each case the data are comprised of monthly data from 1854 until 1990, weekly data from 1990 until 2014, and daily data thereafter. New daily data for the four regions was recently updated. I have a good fit for all the regions. I will display only the daily data for all four regions.

    Region 1.2
    https://1drv.ms/u/s!AkPliAI0REKhgZcMHM-yPIbMjFNs6g
    Region 3.0
    https://1drv.ms/u/s!AkPliAI0REKhgZcMHM-yPIbMjFNs6g
    Region 3.4
    https://1drv.ms/u/s!AkPliAI0REKhgZcJOlB42stKHYEVcg
    Region 4.0
    https://1drv.ms/u/s!AkPliAI0REKhgZcIGhsXZIW78iSN9g
    Just to indicate that I do look at the full dataset for a region here is an earlier analysis of region 3.4.
    https://1drv.ms/u/s!AkPliAI0REKhgZZ7VhO5OcDcTs-t3A

  4. Geoff Sherrington

    Minor comment, Judith.
    Can you please try to break a lifetime custom and avoid using NH seasons as time indicators? Better to use months to help SH readers. Also, expressing dates like 4/1/18 confuses readers in other countries where conventions differ. Better 5 Mar 2018 style. Tks Geoff.

    • Geoff, i had a funny exchange with Spencer on the subject after he replied (to someone with similar concerns), “if you all would just move north, we wouldn’t have that problem!”:

      fonzarelli: Dr. S., if they all did that they would wind up in the ocean…

      spencer: So what’s your point? (translation: fonzie, why don’t you go bother judy for a while?)

      fonzarelli: You’ve just given a whole new meaning to the term down under

  5. “Observers have long noted that cool winter La Niña events often persist or grow into the following winter, in contrast to El Niño events that more frequently undergo rapid spring-summer reversals. From 1980 to 2017, 11 of 14 La Niña winters were repeated by La Niña conditions in the subsequent December. However, reversals have become more frequent in recent years, with all three La Niña to El Niño transitions since 1980 observed in 2006, 2009 and 2014.”

    I think it may be as simple as the equinox as global winds belts move north. ENSO is a recharge/discharge oscillation. La Niña will power on until there sufficient recharge in the western Pacific. With a recharged warm pool instabilities in atmospheric circulation initiates an El Niño.

  6. It is hypothesised that the origins of the Pacific Decadal Oscillation (PDO) and the El Niño – Southern Oscillation (ENSO) are with meridional or zonal wind patterns in polar and sub-polar regions. The PDO is a 20 to 30 year pattern of warmer or cooler sea surface temperature in the north-east Pacific. ENSO is a recharge/discharge oscillation in the tropics and southern sub-tropics – but with a modulation of event frequency and intensity with the same 20 to 30 year periodicity. The warm (cool) phase occurs with low (high) polar surface pressure at the poles. In the warm phase (positive Arctic and Antarctic Oscillation indices) westerly polar winds are constrained closer to the poles – and in the cool phase (negative AO and AAO) winds and storms are pushed into lower latitudes spinning up the Californian and Peruvian Currents – and resulting in enhanced upwelling of cold and nutrient rich water.

    https://watertechbyrie.files.wordpress.com/2017/04/ocean-gyre.png

    The shared periodicity in both the south and north reveals a common mechanism for modulating polar surface pressure. This may involve solar UV/ozone chemistry. “A number of studies have indicated that the decreases in global mean temperature associated with a future decline in solar activity are likely to be relatively small3,4,5,6,7. However, variability in ultraviolet solar irradiance has been linked to changes in surface pressure that resemble the Arctic and North Atlantic Oscillations (AO/NAO)8,9,10 and studies of both the 11-year solar cycle11,12 and centennial timescales13 suggest the potential for larger regional effects. The mechanism for these changes is via a stratospheric pathway, a so-called ‘top-down’ mechanism, and involves altered heating of the stratosphere by solar ultraviolet irradiance.” http://www.nature.com/articles/ncomms8535

    So where is ENSO going? I’d suggest an enhanced flow in the Peruvian Current and very little recharge since the last El Niño says that the current La Niña should hang in for the rest of the year.

    http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/ao.obs.gif
    http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/aao/aao.obs.gif

    The prospects with a looming solar minimum seem even more interesting.

    • Ulric Lyons

      Positive AO, stronger trade winds.
      http://files.abovetopsecret.com/files/img/dt4f28ad37.jpg

      • I am pretty sure you are in the wrong ocean Ulric.

        The figure shows global “wind and gyre circulation changes hypothesized to be associated with multidecadal (a) warm and (b) cool phases of the North and South Hemispheres. White arrows indicate regions of enhanced wind and black arrows indicate areas of enhanced gyre circulation. The blue patches indicate the sinking waters in the North Atlantic. The zonal warm phase occurred from the 1910s to 1940s and 1970s to 1990s and is characteristic of strong westerly winds in the northern and southern hemisphere. North Pacific and North Atlantic subarctic gyre circulations enhance with sinking waters associated with the northern North Atlantic winter. In the Atlantic subtropical gyre circulations also enhance. Some surface waters travel from the Indian Ocean to the south Atlantic and join the Gulf Stream in the North Atlantic. The meridional cool phase occurring from the 1940s to 1970s and 1990s to present consists of equatorward winds over the continents and poleward winds over the subarctic and sub-antarctic oceans, resulting as Rossby wave formations. Intensified circulation in subtropical gyre systems enhances upwelling and productivity in the California and Peru systems. Strengthened easterly trade winds increase equatorial current circulation in the Pacific. The background global chlorophyll is from Yoder et al.” http://www.mdpi.com/2225-1154/3/4/833/htm

      • Ulric Lyons

        The subject is ENSO and not the AMO (which was in its *cold* phase in the 1970s to 1990s). Positive AO/NAO is certainly directly associated with faster trade winds and hence La Nina conditions and episodes.

      • Warm and cool phases relate to surface temperature nad the AO is far less significant for ENSO than the AAO.

  7. 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.

    Cheers.

    Bob

    • To answer my own question, the conditions have been right for westerly wind bursts. They’ve been occurring since the start of this calendar year. Use the attached webpage…
      http://www.cpc.ncep.noaa.gov/products/GODAS/pentad.shtml
      …and under the heading of “Time-Longitude Section Plots” select “Surface zonal wind stress anomaly”

      And in response to those westerly wind bursts, there is a relatively large downwelling Kelvin wave making its way eastward, impacting the equatorial subsurface temperature anomalies:
      http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/enso_update/wkxzteq.shtml

      They will eventually be drawn to the surface and raise sea surface temperatures in the eastern equatorial Pacific.

      Bye

    • Bob, three out of the last four solar mins have had substantial el ninos. Could a simple mechanism like say the slowing of walker trades (due to the solar mins) be the culprit here? Or would you say that it’s just coincidence?

    • Bob
      You tend to be among those cheering on an el Nino but I’m not so sure this time. Rising Nino temps are climatology for spring. The latest NOAA predicts near neutrality till year end:

      https://curryja.files.wordpress.com/2018/04/slide2.png

      OK it looks like a Kelvin wave. But SOI, OLR and trade winds and Peruvian upwelling are all still high/ strong.

    • All through the La Niña upwelling has commenced and quickly sputtered, which is why it’s been weak overall. Anyway, with the PDO in neutral to positive mode, La Niña means very meek cooling. A return to ENSO neutral means a warm 2018, and an EL Niño at the end 2018 may even mean a hot 2018.

      To get a big redistribution of ocean cold to the atmosphere requires a lot of upwelling of cold water from the eastern SH Pacific, which requires a Divine Wind. That’s the lesson of the arming hiatus. And there is no sign off the Divine Wind.

      Obviously skeptics are ignoring my imploring them to prayer. You’re a tribe. Pray for the return of the Divine Wind.

    • This system at the moment shows both a deepening thermocline and higher water levels in the western Pacific. The sub-equatorial trade winds produce a planetary wave that reflects off coastlines and submerges or is deflected along coastlines – just as Bob said. But this is not the fundamental mechanism for the initiation of an El Niño.

      ENSO is a recharge/discharge phenomenon. Energy is stored is the west in elevated water levels as warm surface water is piled up against Australia and Indonesia. This is an unstable wind friction/gravity balance and when the balance collapses a surface Kelvin wave propagates eastward across the Pacific to crash against the coast of the Americas and dissipate north and south.

      https://www.youtube.com/watch?v=hbeWmP0FQOg&t=179s

      Geopotential energy in the west is still fairly modest.

      https://sealevel.jpl.nasa.gov/images/latestdata/ssh/2018/SSHA_20180406_010000.png

      And the wind friction component derives from wind and gyre circulation in the south Pacific. I don’t think it is primed for a collapse just yet – and if it did the result would be a modest El Niño.

  8. The problem with La Nina or an ENSO forecast for 2018 or any year early on is not the springtime predictability barrier.
    The forces, while known to some degree, become more and more unpredictable the further out one goes in time.
    And one does not have to go out very far.
    Basically the system is one in which a fuel load, the sun, puts a slightly variable amount of heat through a much more unpredictable and variable cloud cover which alters the amount of heat received and more importantly where and when it is received as well as how quickly it can radiate out.
    On top of this the air and ocean currents capriciously help retain or emit heat in response to this and to their flow patterns which are also altered by
    the heat uptake and discharge irregularities.

    Hence the system moves between uptaking and discharging heat in patterns which can go from days to several years but eventually must return to the mean.

    Forecasting in advance is possible for up to 3 months as the ocean currents move slowly and retain heat well. The air currents have less predictability usage but generally go in a set direction.

    All one can say is that when the trend departs from zero in either direction one is both closer to achieving an El Nino/La Nina as there is less distance to travel and further away from it happening as the excess or underwight of heat in the system will try to drive it back to neutral.

    For 3 months we can predict where it should go. After that, it should always be a coin toss. With better monitoring available of the heat in the system Judith and others might get their predictions out another week. But unless they know when and where the clouds are going to be for the first 3 months, and they do not and cannot, it will remain a wicked problem

  9. Smith and Sardeshmukh [2000] have created a Bivariate ENSO Time Series (BEST) index that effectively combines the atmospheric component of the ENSO (i.e. the SOI index) with the oceanic component (i.e Nino 3.4 SST
    anomaly index).

    Ref: Smith, C.A. and P. Sardeshmukh, 2000,
    The Effect of ENSO on the Intraseasonal
    Variance of Surface Temperature in Winter.,
    International J. of Climatology, 20 1543-1557.

    Ref: http://www.esrl.noaa.gov/psd/people/cathy.smith/best/

    There is a possibility that some of the weaker El Nino events could be triggered by stochastic processes within the ENSO climate system. Under these circumstances, it would be prudent to:

    a) use Smith and Sardeshmukh’s less stringent criteria to ensure that we have as many El Nino events as possible, to ensure that we have adequate statistics for our analysis.

    b) limit our sample to the those El Nino events that last for more than three months to weed out the marginal or weak events that could be triggered by these stochastic processes.

    https://www.esrl.noaa.gov/psd/people/cathy.smith/best/table33.txt

    Hence, the El Nino events sample that is adopted uses the less stringent selection criteria and only includes those El Nino events that last longer
    than three months.

    The El Nino Events Sample

    The table below shows all of the El Nino Events that meet
    our selection criteria that occurred between 1871 and 2018.

    Table 1
    _________________________Mean___Mean
    _______Starting__Decimal__Delta___Apse
    _Year___Month___Year__Distance__Angle
    https://1.bp.blogspot.com/-gwX64PcBkYU/VGNRFuUrn2I/AAAAAAAAAwU/o33UrNO80mI/s640/Sample.jpg

    2015 March 2015.25

  10. Supplement to Table

    https://4.bp.blogspot.com/-3B9gdN_trd0/VGNhprMVFZI/AAAAAAAAAwo/fJFfWb-8k8Q/s1600/Sample_supp.jpg

    Columns one and two show the starting year and month of each strong El Nino event.

    Column three shows the decimal year of the start of the El Nino event.

    Column four shows the mean difference in lunar distance (in kilometres) between consecutive crossings of the Earth’s equator averaged over
    a period of six months centred on the beginning of the starting month of the El Nino event.

    Ref: Walker J.: Lunar Perigee and Apogee Calculator, 1997, available on-line at: http://www.fourmilab.ch/earthview/pacalc.html,

    Column five shows the mean angle of longitude of the lunar line-of-apse averaged over a period of six months centred on the beginning of the
    starting month of the El Nino event.

    Ref: Ray, R.D. and Cartwright, D.E.: Times of peak astronomical tides, Geophys. J. Int., 168, 999–1004, 2007.

    The El Nino events that have an (*) in column 2 are those events that just fall short of our selection criterion because they only last for three months.

    They have been included in Sample/Table for completeness.

    e) Extending the sample to events prior to 1871

    A data set that extends the SOI index back to 1866 is available for download from the NOAA site at:

    http://www.esrl.noaa.gov/psd/gcos_wgsp/Timeseries/SOI/

    This time series shows that there was a strong El Nino event that started around January 1868. Data for this event has been added as a supplement to the table.

  11. The sample posted above includes all the moderate to strong El Niño events between 1865 and 2018.

    A detailed investigation of the precise alignments between the lunar synodic [lunar phase] cycle and the 31/62 year Perigee-Syzygy lunar cycle, over the time period considered, shows that it naturally breaks up six 31 year epochs each of which has a distinctly different tidal property. The second 31-year interval starts with the precise alignment on the 15th of April 1870 with the subsequent epoch boundaries occurring every 31 years after that:

    Epoch 1 – Prior to 15th April 1870
    Epoch 2 – 15th April 1870 to 18th April 1901
    Epoch 3 – 8th April 1901 to 20th April 1932
    Epoch 4 – 20th April 1932 to 23rd April 1963
    Epoch 5 – 23rd April 1963 to 25th April 1994
    Epoch 6 – 25th April 1994 to 27th April 2025

    Hence, if the 31/62 year seasonal tidal cycle plays a significant role in sequencing the triggering of El Niño events it would be reasonable to expect that its effects for the following three epochs:

    New Moon Epoch:
    Epoch 1 – Prior to 15th April 1870
    Epoch 3 – 8th April 1901 to 20th April 1932
    Epoch 5 – 23rd April 1963 to 25th April 1994

    [That have peak seasonal tides that are dominated by new moons that are predominately in the northern hemisphere]

    https://3.bp.blogspot.com/-UIPnYGwhTcU/VGTNFpoxWBI/AAAAAAAAAxA/Zk2SIxzgm_4/s400/fig_01_IV.jpg

    should be noticeably different to its effects for these three epochs:

    Full Moon Epochs:
    Epoch 2 – 15th April 1870 to 18th April 1901
    Epoch 4 – 20th April 1932 to 23rd April 1963
    Epoch 6 – 25th April 1994 to 27th April 2025

    [That have peak seasonal tides that are dominated by full moons that are predominately in the southern hemisphere]

    Evidence that the Moon Triggers El Niño Events

    Figure 1 below shows the (mean) absolute difference in lunar distance between consecutive transits of the Earth’s equator, versus the (mean) longitude of the lunar line-of-apse.

    Each of the 65 data points in figure 1 represents a six month time interval, with the intervals arranged sequentially across a period that extends from June 1870 to Nov 1902. The 32 year time period chosen is assumed to be reasonably representative of the 153 year period of this study, which
    extends from 1865 to 2018. [N.B. All of the data points shown in figure 1 are obtained by averaging the plotted values over a six month time interval.]

    Shown along the bottom of figure 1 are the months in which the longitude of the lunar line-of-apse aligns with the Sun. This tells us that the line-of-apse aligns with the Sun at the Equinoxes when its longitudes are 0 [March] and 180 [September] degrees, and it aligns with the Sun at the Solstices when its longitudes are 90 [June] and 270 [December] degrees.

    https://3.bp.blogspot.com/-UIPnYGwhTcU/VGTNFpoxWBI/AAAAAAAAAxA/Zk2SIxzgm_4/s400/fig_01_IV.jpg
    Figure 1

    [N.B. The mean longitude of the lunar line-of-apse (averaged over a six month period) moves from left to right across the diagram at roughly 20.34 degrees every six months. This means that it takes 8.85 years (the Cycle of Lunar Perigee) in order to cross the diagram from far left to far right.]

    Figure 1 shows that if you were to randomly select a sample of six month time intervals during the years from 1865 to 2014, you would expect that they should (by and large) be evenly distributed along the sinusoidal shown in this plot.

    Indeed, if you apply a chi-squared test to the data in figure 1, based upon the null hypothesis that there is no difference between number of points within +/- 45 degrees of the time where the lunar line-of-apse aligns with the Sun at the Equinoxes, compared to the number of points within +/- 45 degrees of the time where the lunar line-of-apse aligns with the Sun at the Solstices, then you find that:

    +/- 45 deg. Solstices________33 points
    +/- 45 deg Equinoxes_______32 points

    expected value = 32.5
    total number of points n = 65
    degrees of freedom = 1
    chi squared = 0.015
    and p = 0.902

    This means that we are (most emphatically) unable to reject this null hypothesis.

  12. El Niño Events During the Full Moon Epochs

    Figure 2 shows the corresponding plot for all the El Niño events that are in the Full Moon epochs of the 31/62 year Perigee/Syzygy tidal cycle i.e.

    Full Moon Epochs:
    Epoch 2 – 15th April 1870 to 18th April 1901
    Epoch 4 – 20th April 1932 to 23rd April 1963
    Epoch 6 – 25th April 1994 to 27th April 2025

    Figure 2
    https://4.bp.blogspot.com/-GW7JBreQvC4/VGTaHFb0hyI/AAAAAAAAAxU/y7d8OmNVQWY/s400/fig_03_IV.jpg

    As with figure 1, if you apply a chi-squared test to the data in figure 2, based upon the null hypothesis that there is no difference between number of points within +/- 45 degrees of the time here the lunar line-of-apse aligns with the Sun at the Equinoxes, compared to the number of points within +/- 45 degrees of the time where the lunar line-of-apse aligns with the Sun at the Solstices,then you find that:

    +/- 45 deg. Solstices________2 points
    +/- 45 deg Equinoxes_______11 points

    expected value = 6.5
    total number of points n = 13
    degrees of freedom = 1
    chi squared = 6.231
    and p = 0.013

    This tells us that we can reject the null hypothesis.

    Hence, we can conclude that there is a highly significant difference between number of points within +/- 45 degrees of the time where the lunar line-of-apse aligns with the Sun at the Equinoxes, compared to the number of points within +/- 45 degrees of the time where the lunar line-of-apse aligns with the Sun at the Solstices. The difference is such that the El Niño events in the Full Moon epochs preferentially occur near times when the lunar line-of-apse aligns with the Sun at the times of the Equinoxes.

    It is obvious, however, that the robustness of this claim of significance is not very strong, simply because of the small sample size. Indeed, it would only take two extra data points in the +/- 45 deg. Solstices bin to render the result scientifically insignificant [i.e. a chi-squared of 3.267 and a probability of rejecting the null hypothesis of 0.071]. Ideally, you would like to have at least double the sample size before you would be a little more confident about the final result.

  13. El Nino Events During the New Moon Epochs

    Figure 3 shows the corresponding plot for all the El Niño events that are in the New Moon epochs of the 31/62 year Perigee/Syzygy tidal cycle i.e.

    New Moon Epoch:
    Epoch 1 – Prior to 15th April 1870
    Epoch 3 – 8th April 1901 to 20th April 1932
    Epoch 5 – 23rd April 1963 to 25th April 1994

    Figure 3
    https://4.bp.blogspot.com/-HH0_r1GsHsw/VGTaa0og7NI/AAAAAAAAAxc/4sW4UhUChWY/s400/fig_05_IV.jpg

    As with figure 1, if you apply a chi squared test to the data in figure 3, based upon the null hypothesis that there is no difference between number of points within +/- 45 degrees of the time where the lunar line-of-apse aligns with the Sun at the Equinoxes, compared to the number of points within +/- 45 degrees of the time where the lunar line-of-apse aligns with the Sun at the Solstices, then you find that:

    +/- 45 deg. Solstices________9 points
    +/- 45 deg Equinoxes_______4 points

    expected value = 6.5
    total number of points n = 13
    degrees of freedom = 1
    chi squared = 1.923
    and p = 0.166

    This tells us that we are unable to reject the null hypothesis. However, the El Niño event that has a mean longitude for the lunar line-of-apse of 135.45 degrees in figure 3 could technically be placed in +/- 45 deg. Solstices bin changing the chi-squared to 3.769 and the probability of rejecting the null hypothesis to the scientifically significant value of p = 0.052.

    Hence,we can conclude that there is a marginally significant difference between number of points within +/- 45 degrees of the time where the lunar line-of-apse aligns with the Sun at the Equinoxes, compared to the number of points within +/- 45 degrees of the time where the lunar line-of-apse aligns with the Sun at the Solstices. The difference is such that the El Niño events in the New Moon epochs preferentially occur near times when the lunar line-of-apse aligns with the Sun at the times of the Solstices.

    However, just like the El Niño events in the Full Moon epochs, it is obvious that the robustness of this claim of significance is not very strong, simply because of the small sample size.

    IN SUMMARY

    El Niño events in the Full Moon epochs preferentially occur near times when the lunar line-of-apse aligns with the Sun at the times of the Equinoxes.

    El Niño events in the New Moon epochs must preferentially avoid times when the lunar line-of-apse aligns with the Sun at the Equinoxes.

    Prediction: Since we are currently in a 31 year Full Moon Epoch for El Niño events, there should be a heightened probability of experiencing a moderate to strong El Niño in the following years:

    2019-2020 and
    2024

    as these are the years where the lunar line-of-apse aligns with the Sun at the times of the Equinoxes.

    • There is a possibility of an El Nino starting in 2018 that is a part of a continuing 9.05-year sequence for the starting dates of El Ninos:

      1982.3 / 1991.4 / (2000.4) / 2009.5 / 2018.5 [with a half sequence at 1986.9]

      These El Ninos belong to those that start when the line-of-apse of the lunar orbit points towards the Sun at the times of Summer and Winter Solstices.

      This contrast with the El Nino sequence:

      1997.3 / 2006.4 / 2015.4 / 2024.5 [with half sequences at 2001.9 / 2020.0 ?]

      These El Ninos belong to those that start when the line-of-apse of the lunar orbit points towards the Sun at the times of Vernal and Autumnal Equinoxes.

  14. Pingback: Will There Be A 2018/19 El Niño? | Bob Tisdale – Climate Observations

  15. Pingback: Will There Be A 2018/19 El Niño? | Watts Up With That?

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  17. Fascinating read. Trying to understand drivers of a well known but not well understood repeating natural phenomenon. Sort of 4/5 chance of Modoki or stronger half a year out. Look forward to seeing how that prediction pans out.

  18. Today I read in USA Today that Phillip Klotzbach of Colorado State University predicted a 60% chance of an above average number and severity of Atlantic hurricanes this season with more hurricanes making US landfall. The article noted that Klotzbach predicted fewer Atlantic hurricane last year and there were more. I wonder if this year’s predictions are using using the same prediction model from last year?

    The article mentioned that a cooler Eastern Equatorial Pacific sea surface temperatures accentuated the temperature gradient between a warm Atlantic and the cooler Equatorial Pacific such that hurricane formation would be enhanced.

    It is my understanding that a warm Equatorial Pacific sea surface temperature via an El Nino would create high altitude wind shear and thwart hurricane formation; hence, fewer Atlantic hurricanes.

    After reading Judith’s article it appeared to me that a large part of Atlantic hurricane predictions involves predicting the phase and duration of ENSO.

  19. Waiting for el Ninot, scene 5

    Adapted from http://samuel-beckett.net/Waiting_for_Godot_Part1.html

    ESTRAGON: People are bloody ignorant apes.
    VLADIMIR: Pah!
    ESTRAGON: Charming spot. Inspiring prospects. (He turns to Vladimir.) Let’s go.
    VLADIMIR: We can’t.
    ESTRAGON: Why not?
    VLADIMIR: We’re waiting for el Ninot.
    ESTRAGON: (despairingly). Ah! (Pause.) You’re sure it was here?
    VLADIMIR: What?
    ESTRAGON: That we were to wait.
    VLADIMIR: He said by the tree. (They look at the tree.) Do you see any others?
    ESTRAGON: What is it?
    VLADIMIR: I don’t know. A bristlecone pine.
    ESTRAGON: Where are the leaves?
    VLADIMIR: It must be dead.

  20. “The meridional cool phase occurring from the 1940s to 1970s and 1990s to present consists of equatorward winds over the continents and poleward winds over the subarctic and sub-antarctic oceans, resulting as Rossby wave formations.” op. cit.

    The north/south excursion of circumpolar winds are driven by higher polar surface pressure – that is in part solar mediated.

    “The mechanism for these changes is via a stratospheric pathway, a so-called ‘top-down’ mechanism, and involves altered heating of the stratosphere by solar ultraviolet irradiance. Anomalous temperatures in the region of the tropical stratopause give rise to changes in the subtropical stratospheric winds, in geostrophic balance with the modified equator-to-pole temperature gradient. This signal then propagates poleward and downward and is amplified by altered planetary wave activity8 before being communicated throughout the depth of the troposphere in the Pacific and Atlantic basins14.” https://www.nature.com/articles/ncomms8535

    The global energy budget is modulated by cloud change anti-correlated to SST changes.

    “We emphasize that the NE Pacific cloud changes described above are tied to cloud changes that span the Pacific basin. Despite much less surface sampling in the Southeast (SE) Pacific, cloud and meteorological changes in that region generally occur in parallel with those in the NE Pacific (Figs. 2 and 3). Also, we find that the leading mode in an empirical orthogonal function analysis (15% of the variance) of global cloud cover (fig. S3) has a spatial pattern similar to that in Fig. 3 and the time series shows the same decadal shifts as in Fig. 1, indicating that the changes in the NE Pacific are part of a dominant mode of global cloud variability.”
    https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00003.1

    It seems that beyond decadal modulation of the global energy budget – this is a mechanism of centennial scale amplification of solar variability. The 20th century saw a 1000 year high in El Nino intensity and frequency.

    https://watertechbyrie.files.wordpress.com/2015/12/vance-2012-e1520868687324.jpg
    https://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00003.1

    https://watertechbyrie.files.wordpress.com/2015/10/isotopes.png

    And there is of course millennial variability.

    https://watertechbyrie.files.wordpress.com/2014/06/moys-20023.png

    Christopher Moy and colleagues examined a sediment core from Laguna Pallcacocha in southern Ecuadora. More rainfall and runoff In El Niño conditions wash more red sediment into the lake. So we know it was pretty rainy in South America a 1000 years ago. Some 5,000 years ago there was a change from dominant La Niña anomalies to dominant El Niño – that dried the Sahel. Just 3,500 years ago there were a long series of El Niño with red intensity greater than 200 and civilisations fell. For comparison – red intensity in the ‘monster’ 1997/1998 El Niño event was 99.

    The mid-Holocene transitions appears as well in the cosmogenic isotope record.

    http://www.pnas.org/content/pnas/109/16/5967/F3.medium.gif

    Will there be more La Niña over the next centuries? Can we expect more El Niño in a thousand years? Might we see great herds return to the Sahel? The details of the future evolution of climate remains absolutely uncertain. What is more certain is that the next global climate shift is due in a 2018-2028 window. The next shift may be to yet cooler conditions – given the 20th century high in both solar activity and El Niño intensity and frequency. Regardless of near term outcomes – it is odds on for a cooler sun and more upwelling in the Pacific Ocean this century – providing a cooling influence on the oceans and atmosphere and the inevitable regional variability in rainfall.

    • “The role of tropical Pacific SSTs in driving global medieval hydroclimate is assessed. Using fossil coral records from Palmyra Atoll, tropical Pacific sea surface temperature (SST) boundary conditions are derived for the period 1320–1462 A.D. These boundary conditions consist of La Niña‐like mean state conditions in the tropical Pacific with inter‐annual and decadal variability about that altered state…

      For the western US, paleo‐reconstructions of drought conditions indicate that the droughts of the last 150 years are considerably less severe and protracted than those that have been estimated for time periods in the 12th and 13th century from tree ring data [Woodhouse and Overpeck, 1998].” https://agupubs.onlinelibrary.wiley.com/doi/full/10.1029/2009GL042239

      The question is less if this will happen again but when.

      • The question is less if this will happen again but when.

        Yes, history repeats. past cycles of warm and cool and warm and cool will continue into the future with warm and cool and warm and cool.

        it snows more during warm when oceans are more thawed and it gets cool after. it snows less during cool and it gets warm after. as to when, we can use past timing for a guide, with a lot of leeway.

    • “To understand the impact of decadal variability in the Pacific on global and regional climate, one only needs to look at the last 16 years. In the late 1990s the tropical Pacific sea surface temperatures (SSTs) transitioned to a La Niña‐like cool phase, reversing the El Niño‐like conditions that had persisted since the late 1970s. The cool conditions in the tropical Pacific have been linked to changes in regional sea level rise [Hamlington et al., 2013], strengthening of the large‐scale atmospheric circulation [Chen et al., 2008; Burgman et al., 2008b], a reduction in the rate of increase in the global mean surface temperature [Meehl et al., 2011; England et al., 2014], and persistent drought conditions in North America [Hoerling and Kumar, 2003; Schubert et al., 2004, 2009; Seager et al., 2005, 2008; Burgman and Jang, 2015].

      For decades, researchers have investigated the spatial and temporal characteristics of decadal variability in the Pacific over the past century and its influence on the ocean and atmospheric circulation, regional climate, and marine ecosystems. Using surface observations and differing metrics, several authors identified several “regime shifts” in the Pacific over the past century occurring in the mid‐1920s, the mid‐1940s, and in the late 1970s [Trenberth and Hurrell, 1994; Mantua et al., 1997; Zhang et al., 1997; Power et al., 1999]. The SST structure of Pacific decadal variability (PDV) is characterized by a broad triangular pattern in the tropical Pacific surrounded by opposite anomalies in the midlatitudes of the central and western Pacific Basin. In the late 1990s and early 2000s the Pacific transitioned to the cool La Niña‐like phase of the oscillation [Chen et al., 2008; Burgman et al., 2008b; Jo et al., 2013]. This cool PDV pattern persisted until very recently, when a large pattern of warming expanded throughout much of the Northeast Pacific, indicating a possible shift back to the positive phase.” https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2016GL071978

      https://watertechbyrie.files.wordpress.com/2018/04/el-nino-la-nina1.jpg

      Could we get 20 to 30 years of natural warming in the context of the prospect for centuries of cooling as insolation declines and the Pacific Ocean responds? The solar modulated cool and warm phase hypothesis says no – but these things are complex and dynamic.

    • From the millennial to the near real time. Low pressure cells – counterclockwise in the NH and clockwise in the SH – can be seen spinning off the polar regions as a result of recent more negative polar annual modes. The polar modes have intense and frequent variability – and the hypothesis is that the modes are biased to one state or another by changes in solar UV emissions. Both polar modes drifted to more positive values in the latter decades of the 20th century with a more negative turn at about the mid 1990’s.

      https://watertechbyrie.files.wordpress.com/2018/04/earth-null-7-4-2018.jpg

      The live version is cool – https://earth.nullschool.net/#current/wind/surface/level/overlay=mean_sea_level_pressure/equirectangular=-136.27,-1.73,201/loc=-140.932,51.972 – I have placed a green circle in the Aleutian Low.

      The NCEI PDO is -0.51 for March showing further cooling. The ENSO cold tongue remains with some intense upwelling in the east.

      https://watertechbyrie.files.wordpress.com/2018/04/earth-null-7-4-2018.jpg

      The solar modulated sub-polar wind and gyre – with enhanced upwelling in negative polar annular modes – hypothesis suggests a higher probability of La Niña in the vicinity of solar lows. Data points are a bit sparse as yet. I might do some actual work on extended indices – but in principle I’d expect there to be a bias to one state or another rather than a strong correlation. In addition to the multi-factor variability of the polar annular modes there is the resonant response of the system itself.

    • Robert I Ellison: Could we get 20 to 30 years of natural warming in the context of the prospect for centuries of cooling as insolation declines and the Pacific Ocean responds?

      That is a cool series of posts.

      The live version is cool –

      Thank you for the immediately following link.

    • “given the 20th century high in both solar activity and El Niño intensity and frequency. Regardless of near term outcomes – it is odds on for a cooler sun and more upwelling in the Pacific”

      The reverse, low solar leads to increased El Nino conditions.

      • More salt in this Law Dome ice core ENSO proxy is La Nina – and more rain in Australia. It is a mirror of the cosmogenic isotope record over the last 1000 years.

        https://watertechbyrie.files.wordpress.com/2014/06/vance2012-antartica-law-dome-ice-core-salt-content.jpg

        The physical linkage is between the Southern Annular Mode, the strength of the Humboldt current and subsequent upwelling off Peru. Negative SAM spins up the south Pacific gyre. Negative SAM (and NAM) are associated with low solar activity.

        https://watertechbyrie.files.wordpress.com/2017/04/ocean-gyre.png

        The figure shows global “wind and gyre circulation changes hypothesized to be associated with multidecadal (a) warm and (b) cool phases of the North and South Hemispheres. White arrows indicate regions of enhanced wind and black arrows indicate areas of enhanced gyre circulation. The blue patches indicate the sinking waters in the North Atlantic. The zonal warm phase occurred from the 1910s to 1940s and 1970s to 1990s and is characteristic of strong westerly winds in the northern and southern hemisphere. North Pacific and North Atlantic subarctic gyre circulations enhance with sinking waters associated with the northern North Atlantic winter. In the Atlantic subtropical gyre circulations also enhance. Some surface waters travel from the Indian Ocean to the south Atlantic and join the Gulf Stream in the North Atlantic. The meridional cool phase occurring from the 1940s to 1970s and 1990s to present consists of equatorward winds over the continents and poleward winds over the subarctic and sub-antarctic oceans, resulting as Rossby wave formations. Intensified circulation in subtropical gyre systems enhances upwelling and productivity in the California and Peru systems. Strengthened easterly trade winds increase equatorial current circulation in the Pacific.” http://www.mdpi.com/2225-1154/3/4/833/htm

        This hypothesis has explanatory power but the correspondence of SAM to solar activity is not linear. It may bias the Pacific resonant system to one state or other. Eyeballing in correlations between ENSO and solar activity is a fools errand.

      • The largest clusters of multi-year drought in Australia were during solar minima, because of the increase in El Nino conditions.
        https://australia-nature.wikispaces.com/Drought+in+Australia#x-Droughts%20in%20the%2019th%20century

      • “The Quinn index, which is a much longer proxy time series than is available in the instrumental record, suggests that cold ENSO and warm ENSO are almost equally distributed at solar peak years and implies that they are an independent phenomena.” https://journals.ametsoc.org/doi/full/10.1175/JAS-D-12-0101.1

        Over the Schwabe cycles the internally generated ENSO beat has it’s own dynamic. In the much longer term there is a peak in El Nino intensity and frequency in the 20th century following centuries of La Nina dominance. but the primary observation is not this.

        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. Negative SAM and NAM are associated with lower solar activity. 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.

      • “suggests that cold ENSO and warm ENSO are almost equally distributed at solar peak years and implies that they are an independent phenomena”

        Independent of UV variability yes, but not independent of the solar wind strength.

  21. So, the outlook (an El Niño winter) for southern California means we would be more than usual rainfall and stormy weather (flooding, erosion, landslides) this winter and possibly an earlier winter. Good to know.

  22. The forecasting by the models r ENSO events is not good in the least.

  23. for ENSO events

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  27. “So, why is the accuracy of the models so bleak during the spring? Is there reason to believe that more model development will improve upon the low skill we see during the spring? While there are many ideas on why the spring barrier exists, there are no definitive culprits (Webster and Yang, 1992, Webster, 1995, Torrence and Webster, 1998, McPhaden, 2003, Duan and Wei, 2013).

    One of the reasons that the spring barrier is said to exist is because spring is a transitional time of year for ENSO (in our parlance, signals are low and noise is high). The spring is when ENSO is shifting around— often El Niño/La Niña events are decaying after their winter peak, sometimes passing through Neutral, before sometimes leading to El Niño/La Niña later on in the year. It is harder to predict the start or end of an event than to predict an event that is already occurring. There is also weaker coupling between the ocean-atmosphere in the spring due to a reduction in the average, or climatological, SST gradients in the tropical Pacific Ocean. However, for various reasons, these factors don’t fully explain why we see lower skill (6).”
    https://www.climate.gov/news-features/blogs/enso/spring-predictability-barrier-we%E2%80%99d-rather-be-spring-break

    https://www.climate.gov/sites/default/files/styles/inline_all/public/WinterForecast_610_alt2.png

    Unless there has been a very recent breakthrough – you may as well toss a coin this time of year. I think the problem may be as simple as thermal instabilities as the Sun crosses the equator initiating El Niño in the right conditions of ocean mounding in the western Pacific. Recharge in the western Pacific in the weak 2017/18 La Niña is modest as yet – any emergent El Niño would be likewise moderate. The safest prediction would seem to be ENSO neutral but surprises are inevitable. I’d say that there is a greater likelihood of a La Niña surprise.

    As of now – surface pressure differences are lower again in Darwin as compared to Tahiti and winds and currents are still pushing moderately strongly north along the Peruvian coast – before diverging from the coastline nearer the equator. The MEI fell a little in Feb/Mar marginally into neutral territory. An MEI ranking of 22 rather than a weak La Niña ranking of 21.

    https://www.esrl.noaa.gov/psd/enso/mei/comp.png

    Anomalous easterlies near the equator seem sufficient to maintain the current state a little longer. Winds and south Pacific gyre flows depend directly on the state of the south polar annual mode (SAM or alternatively AAO).

    http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/aao/aao.obs.gif

    A continuation of a more negative AAO state is somewhat unpredictable – the hypothesis is that it is in part the result of solar uv/ozone chemistry in the upper atmosphere translating through atmospheric pathways to polar surface pressure – e.g. Ineson et al 2015. But a continuation presages enhanced flow in the Humboldt Current, more upwelling on the eastern margin and a La Niña intensification. Regardless – we will need to wait until the Inter Tropical Convergence Zone moves south again with the Sun to get a better idea of which way the equatorial trade winds are blowing.

    • …The next update for the MEI is expected by March 12th { I think Wolter means May 12} or earlier. Compared to last month, the odds for continued La Niña conditions for the next few months are now worse than 50% in the MEI sense, while the odds for El Niño appear to gain the upper hand during the second half of the year, but only slightly. Meanwhile, the PDO showed its lowest value since January 2014 in October (+0.05), followed by rise back up to +0.70 in January 2018 and back down to +0.37 in February. At least for now, the PDO is still projecting onto its positive phase. Daily updates of the ENSO status can be found at the TAO/TRITON website, showing weakened La Niña conditions in early April over the equatorial Pacific, along with weak anomalous southeasterlies near the dateline that might just be sufficient to maintain status quo (weak La Niña) for a little while longer.

      • I was going to email about the date.

        “Daily updates of the ENSO status can be found at the TAO/TRITON website, showing weakened La Niña conditions in early April over the equatorial Pacific, along with weak anomalous southeasterlies near the dateline that might just be sufficient to maintain status quo (weak La Niña) for a little while longer.”

        But that’s pretty much what I said about current conditions. And yes I can read.

        As for the PDO – SST over the region cooled again last month. From the NCEI PDO.

        201707 -0.49
        201708 -0.62
        201709 -0.25
        201710 -0.60
        201711 -0.46
        201712 -0.13
        201801 0.29
        201802 -0.17
        201803 -0.51

    • “Unless there has been a very recent breakthrough – you may as well toss a coin this time of year. I think the problem may be as simple as thermal instabilities as the Sun crosses the equator initiating El Niño in the right conditions of ocean mounding in the western Pacific. Recharge in the western Pacific in the weak 2017/18 La Niña is modest as yet – any emergent El Niño would be likewise moderate. The safest prediction would seem to be ENSO neutral but surprises are inevitable. I’d say that there is a greater likelihood of a La Niña surprise.”

      The main cause of unpredictable thermal instability is cloud cover.
      There should probably be a direct link between increased cloudiness and the onset of La Niña conditions from the first three months of Spring onwards. Not that this would help in predicting because it is happening not happened.It should be obvious in retrospect. The degree of ocean conditions extant is probably not as important as they should already be known in advance (expected depth, temp, winds etc).

  28. Global SSTs have fallen a third of a degree in less than 3 years from the 2016 Nino peak. The biggest fall in 40 years. It’s starting to look like more than just post el Nino correction.

    http://www.climate4you.com

      • La Nina conditions continue – and of the course the skill of these models this time of year is ‘bleak’. Yet he keeps posting them expecting a different response. Isn’t that the definition of madness?

        I’d watch the Nino 1+2 region (the Humboldt Current) rather Nino 3.

        https://www.ncdc.noaa.gov/teleconnections/enso/indicators/sst.php

      • Niño 1.2 has been blinking hot and cold throughout the now completely dead La Niña.

        … Recent advances in global seasonal forecast models appear to be breaching the predictability barrier to some extent. We have conducted a climate dynamics analysis seeking to identify the sources of this extended range ENSO predictability. We have identified DJF precursor signals in upper tropospheric and stratospheric anomalies at high latitudes of both hemispheres, consistent with research showing important extratropical forcing of surface wind anomalies and SST responses in the equatorial and off-equatorial Pacific. …

        So, how might all this actually translate into a useful forecast for 2018 ENSO conditions? My company Climate Forecast Applications Network (CFAN) has issued our first long-range ENSO forecast. I look forward to your feedback. …

        CFAN’s analysis of the ENSO hindcast skill of the ECMWF SEAS5 shows a correlation coefficient of 0.73 for Niño3.4 forecasts initialized in April for the next seven months (October).

    • The Humboldt current is the origin – upwelling that creates feedbacks across the Pacific – of the La Nina that continues in the equatorial Pacific. “It is considered that La Niña conditions continue in the equatorial Pacific” – being the first line of his own link.

      “The PCCS (Peru–Chile Current System) has a rather tight connection to the equatorial Pacific and the globally strongest mode of interannual variability; the ‘El Niño/Southern Oscillation (ENSO)’ propagates via atmospheric and oceanic pathways into the PCCS and provokes specific physical and ecological responses. ” https://www.sciencedirect.com/topics/agricultural-and-biological-sciences/humboldt-current

      “Recent advances in global seasonal forecast models appear to be breaching the predictability barrier to some extent.” So CFAN claims that 50% of the variance 7 months out from April can be explained by the new ECMWF SEAS5 dynamical, probabilistic model?

      “One ‘ensemble forecast’ consists of 51 separate forecasts made by the same computer model, all activated from the same starting time. The starting conditions for each member of the ensemble are slightly different, and physical parameter values used also differ slightly. The differences between these ensemble members tend to grow as the forecasts progress, that is as the forecast lead time increases.”

      I am not sure how this works as the explanations of procedures are lacking – but I suppose it is a slight improvement over the NOAA skill estimates I linked to above.

  29. “Atmospheric precursors of El Niño transitions likely reflect contributions from multiple large-scale mechanisms, rather than a single, continuous process.”

    They likely reflect the effects of the solar wind coupling at the polar regions.

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  31. Sliding into NOAA’s La Niña zone of death:

    https://i.imgur.com/VQL0LMU.png

    Reinforcements from Niño 1.2 getting decimated:

    https://i.imgur.com/VGsFp6o.png

    Small bone, JIASO PDO slightly negative:

    https://i.imgur.com/xLRDbdd.png

  32. Until there is an understanding of the origins of cool and warm conditions in the eastern Pacific – it is all just whistling in the wind. Negative values of the polar annular modes spin up the south and north Pacific gyres and enhance upwelling. The latter creates feedbacks across the Pacific. The origin of ENSO is upwelling in the Nino 1+2 region – in which stronger upwelling is happening.

    https://www.youtube.com/watch?v=EjlIeQFxdlE&list=PL75CBFA21C7B6F783

    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. 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.

    The eastern Pacific has cooled and the La Nina pattern remains. Easy enough to see – even in JCH’s 7 day weather change. The NCEI PDO is -0.51 for March. It is as I have explained before – not a matter of which is right. They are both equivalent – the zero point in the index is somewhat arbitrary – and both show cooling in the north-east Pacific. This is a predictable outcome of meridional blocking patterns emerging from the pole that brought such storminess in the boreal winter.

    As far as ENSO is concerned – there has been a short lived El Nino followed by a modest La Nino. There is quite simply insufficient recharge in the western Pacific for a significant El Nino to emerge. Everyone seems to be predicting neutral conditions because nothing is all that pronounced. But the wild card is the potential for the upwelling that drives this system.

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