What happened to ENSO?

[Artful Dodger]

Hi folks,

There are three climate patterns on planet Earth that override all other factors. These are, in decreasing order of effect:

• the rotational 'day/night' diurnal pattern,
• the orbital inclination 'seasonal' or 'annual' pattern, and
• the El Niño–Southern Oscillation 'ENSO' pattern.

During Northern Autumn of 2012, something happened to El Niño, something unprecedented in Human history, and perhaps something that has never happened before.

A building El Niño has faded, and failed to appear. This was completely unexpected by the various National Forecasting agencies, and remains unexplained to this day.

Whatever happened, it is more powerful than the third greatest climate forcing on Earth.

So then I ask you, what has happened to El Niño?

[ghoti]

Looking at the history of the ENSO at http://www.cpc.ncep.noaa.gov/products/analysis_monitoring/ensostuff/ensoyears.shtml I'm not convinced the current run of La Nina / neutral is unusual historically. Looks like there have been many multi-year stretches without the appearance of El Nino.

[Neven]

Ghoti, this is true. But what is weird, is that all the conditions were pointing to El Niño, and then, all of a sudden, everything flipped again, and now it looks like it's going to be neutral for a couple of months. I don't know if this has happened a lot, probably not since observations/modeling started.

[werther]

Thanks, Lodger, for bringing this intriguing issue into the Forum.
I've had this in my mind since November, as I was very involved in categorizing NCEP/NCAR decadal means in the pursuit of 'wacky' weather.
As I haven't a clue yet on how the mechanism might work, I would be very interested to hear FI what R.Gates' opinion is. He seems to have a good grasp on the longitudinal graphs describing the atmospheric pressure developments.
I read lately that SSW's often form over the Tibetan Plateau, working their way into the Arctic high in the stratosphere. I wonder how much heat transfer could have happened in that period in the western Pacific, out of the ENSO-zone. Remember the incredible typhoons out there? Like Bopha? Could this sort of processes anomalously 'kill' 'El Nino'? Could it have influenced the particular patterns in both Polar regions? Both showed anomalous pressure patterns...

[icebgone]

Werther,  I think you have described the primary reason for the sudden cessation of ENSO.  Vertical mixing at depth could easily have transferred a substantial amount of heat from surface waters into deeper water.  If so, then we should be able to measure a temperature increase in mid-level ocean layers.  Are there any Argo floats in the area of interest?  A series of 500-2,000 meter depth readings should be revealing.  If this is the mechanism, then it also means the amount of energy waiting to be vented during the next ENSO will be much larger.  Is there any connection with Antarctic melting?  I also find the timing rather curious as this was about the time that Sandy was making its appearance in the Atlantic and along the Northeast U.S. coastline.

[Bruce Steele]

The pacific decadal oscillation is currently negative and for the west coast of north America it has a powerful effect. I know there are large parts of the pacific that are warm during the negative phase  but the earth temperature anomalies and the PDO phase show interesting parallels. I realize speculation without a explanation for what would cause the PDO to effect world temperature trends is speculation. Biologically the PDO has it's influence but biology is messy business. For a fisherman however it is a good predictor and much longer lived( biological effects) than the ENSO.   

[Bruce Steele]

//www.skepticalscience.com/Is-Pacific-Decadal-Oscillation-the-Smoking-Gun.html.   Here is a skeptical science piece from five years ago. Although the PDO flipped negative -positive (2009)and back negative, eleven of the last 13 years have been negative. The parallels with temperature trends are still holding.   

[werther]

The faded El Nino had its peak at a 3-month mean of +0.6 during last October. As the peak geographically shifted from East to West, it had a 'Modiki-Nino' aspect just before it started fading out.
Icebgone introduced downward mixing of heat to deeper ocean layers. In my hurry to speculate on the role of cyclones I forgot that process. He's right, considering what we know about the vast storage of heat in these deeper layers and the upwelling near Antarctica in the Amundsen Sea. Still, I wouldn't be surprised if both processes could be identified to have this intertwining effect on FI ENSO. After all, since 2010 (Igor), 2011 (Irene) and 2012 (Sandy) the character of cyclones is changing. While they do not seem to score high on the Saffir-Simpson scale, they transfer enormous amounts of energy measured by their diameter.
A speculative analysis is that all these processes underline the intensifying loss of the zonal gradients through the atmosphere and the oceans. In other words; the schematic, orderly identification of the Hadley-Ferrell and Polar cells is shifting and something similar is working its way through the thermohaline sirculation in the oceans.
But... can it be identified? How fast? Where will the inevitable anomalies occur?

[werther]

On my earlier post... I know I mentioned only Atlantic storms to illustrate my claim that the character of cyclones has changed (most specifically later in the season). I am not very courant with the East Pacific typhoons. But, FI Bopha was equally weird. Close to the Equator etc.

[Artful Dodger]

UCAR Communications Officer Bob Henson offered this blog update on November 9, 2012:

¡Hola, La Nada! - "What happens when El Niño and La Niña take a break?"

In it, Bob shows how the ENSO pattern evolved over the period Feb-Sep 2012, only to collapse rapidly in Sep 2012:



Bob goes on to say:

If there’s anything striking about current ocean conditions around the globe, it’s the impressive blobs of warmer-than-usual water located off the midlatitude coasts of Asia and North America, close to where the Kuroshio and Gulf Stream currents branch out into the North Pacific and North Atlantic, respectively.

So I think in this there may be the beginning of a new hypothesis:

"Meridional heat transport has increased to the point where it now overpowers the heat transport due to ENSO (at least, it is stronger than a mild el Nino)."

Increíblemente imposible hijo asesino. Si es así, ¿qué hemos hecho?

[Artful Dodger]

Icebgone introduced downward mixing of heat to deeper ocean layers. In my hurry to speculate on the role of cyclones I forgot that process. He's right, considering what we know about the vast storage of heat in these deeper layers and the upwelling near Antarctica in the Amundsen Sea.

Hola, Werther!

I'd have to see salinity data from fixed tethered buoys and sea skimmers before I speculate along this line. The density of sea water (which is what drives deep ocean mixing) depends far more on its salinity than it's temperature. Too bad the U.S. Navy at Pearl doesn't provide public access to this data. Their nuclear sharks prowl the first 400 m of those seas, and have for decades.

A speculative analysis is that all these processes underline the intensifying loss of the zonal gradients through the atmosphere and the oceans. In other words; the schematic, orderly identification of the Hadley-Ferrell and Polar cells is shifting and something similar is working its way through the thermohaline circulation in the oceans.
But... can it be identified? How fast? Where will the inevitable anomalies occur?

Well, the AO is negative right now, but was not strongly so in the Fall. There is a mechanism for meridional atmospheric heat transport (ENSO teleconnections, the atmospheric bridge), but does this have even 1/10,000^th the heat capacity of ENSO? Enough energy to move the Eastern Pacific Ocean? I surely do no know!

The atmospheric bridge during el nino

Well the 'atmospheric bridge' may well be at work, but if it is it will leave these fingerprints: (from the Wikipedia page linked above)

"The atmospheric bridge is more effective during boreal winter when the deepened Aleutian low results in stronger and cold northwesterly winds over the central Pacific and warm/humid southerly winds along the North American west coast, the associated changes in the surface heat fluxes and to a lesser extent Ekman transport creates negative sea surface temperature anomalies and a deepened MLD in the central pacific and warm the ocean from the Hawaii to the Bering Sea."

Anybody seen these signs? That'd be strong evidence, I think. 

[Artful Dodger]

Let's take a quick detour with another look at the density of sea water as a function of temperature and salinity (attached). The red line is the freezing point of salt water, the blue line is for fresh water.

Using the density curves plotted in the chart, we can see that sea water at +27.5 C (temp) and 35 psu (salinity) has the same density as sea water at -2 C and 28 psu.

For the purposes of estimating ocean currents, salinity is a HUGE determining factor. This is why brine rejection in Arctic sea ice and the freshening of the surface layer has such a huge effect on the Arctic.  When warm but salty water enters from the Pacific, it wants to sink and spread!

[Artful Dodger]

Let's highlight this chart from Bob Henson's blog post: (linked up-thread) Image credit: NOAA - Oct 12, 2012.


ENSO is far and away the weakest of the three concentrations of warm surface water in the Northern Pacific. Bebé pobre, it had nowhere to go!

The next ENSO Diagnostics Discussion is scheduled for 7 March 2013.

In his blog post, Bob Henson goes on to say:

During October 2012, waters off the midlatitude coast of Asia and North America were unusually warm—more than 2°C (3.6°F) above average in some cases. (Image from Monthly Ocean Briefing, courtesy NOAA Climate Prediction Center.)

EDIT: Let's compare the two PDO patterns: (h/t Bruce Steele for the image)



Positive phase (cool in W. Pac) vs Negative phase (warm in W. Pac)

To me, Oct 2012 was NOT the normal PDO pattern. The Northern Pacific was dominated by warm SSTs on both the Western and Eastern sides, with a slug of cooler water in the mid-Pacific.

Something else is afoot here, folks.

[Neven]

What kind of PDO is that?

[Artful Dodger]

What kind of PDO is that?

Hi Neven,

The Wikipedia page (linked upthread) show this a the "PDO positive phase global pattern". That would be with the NW Pacific (Asian side) cool, and the NE Pacific (American side) warm.

The PDO negative phase would be the opposite, with NW warm and NE cool.

The point being, there's no PDO phase with warm on both sides. What we saw in Oct 2012 is NOT the result of the PDO.

[Artful Dodger]

Now you see El Niño, now you don’t
"The tropical Pacific is keeping us in suspense"
Bob Henson • September 28, 2012

This blog posted earlier in 2012 talks about the influence of the PDO:

Other factors are also in play. The Interdecadal Pacific Oscillation (IPO), which affects ocean temperatures as well as North American climate, has been in a cold (negative) phase since around 1999. This tends to work in ways similar to La Niña, fostering drought across the western and central United States, according to Aiguo Dai (now at the University at Albany, State University of New York). Thus, any El Niño that does develop might face countervailing influences from the IPO, though these interactions are poorly understood.

This important point was made by NCAR scientist Kevin Trenberth:

There’s another elephant in the room: the long-term influence of greenhouse gases. “In my view, El Niño and La Niña are very likely changing as a consequence of climate change, but such changes cannot be measured when you get only one event every three to seven years,” says Trenberth. “The natural variability is enough to make it is impossible to determine a climate change signal.” Still, he adds, when it comes to El Niño and La Niña, it’s best not to assume that past performance is any guarantee of future results.

So then, back to my hypothesis...

[Gray-Wolf]

If we are indeed seeing Arctic Amplification impacts in our current northern Hemisphere circulation patterns then surely this must also have some impact on the 'normal running' of the ENSO system?
I've seen papers noting a growing impact , since the 1980's, of our warming on the PDO (background warming meaning less 'cold temps and more neutral/positive temps) and if PDO phase is also interlinked with a predominance in ENSO state (PDO-ve linked to Nina's and +ve to Nino's) then changes to the PDO must also impact the ENSO cycles?

We have also seen a growth in the number of 'shifted' Nino's with the bulk of the Warmth out to the west suggesting ,again, that something is altering in the old 'ENSO' workings.

The other thing is a request for clarity on something. does the longer we stay neutral/Negative allow for a deeper build up of warmth awaiting it's chance to be brought to the surface (super Nino)? I may well have just dreamed it but I'm sure I read a discussion pointing out this 'quirk'? Are we really awaiting the appearance of a 'Super Nino' due to this long period of accumulation?

[Bruce Steele]

http://jisao.washington.edu/pdo/pdo_warm_cool3.jpg.  The current negative phase of the PDO has resulted in cool waters along the Washington ,Oregon and Calif. Coast which is expected. It also has warm waters in the western pacific around Japan also expected, so other than a large pool of warm water 1000 miles off the Canadian - U.S. border this negative phase PDO looks fairly normal to me. In my earlier post I didn't mean to imply the PDO had stopped the development of a potential ENSO event.As Grey-Wolf says the phase of the PDO does have an effect on the intensity of ENSO either positive phase or negative phase. Until someone can explain the mechanism which drives the PDO cycle we are stuck with speculation as to how it interacts with the better understood ENSO cycle.   

[Bruce Steele]

Sorry for the failed link. I was trying to show the negative phase graphic.

[werther]

Following this mornings posts, I checked the SST global maps. They don't tell much about heat content in the deeper layers. But some interesting differences with last year speak out on the maps.
It looks like an El Nino pattern is weakly appearing again. And what about the large warm area west of southern Chile, right into the Amuundsen Sea.
And the Cape Verde/Gulf of Guinea region in the Atlantic doesn't bode well for the Atlantic hurricane season.

[icebgone]

The mid-latitude warm pools are also home to a growing collection of human trash - primarily plastics that remains floating on the surface or suspended in the top 100 meters of the water column.  Area of extent ranges from 600,000 - 1,300,000 km2, so fairly small compared to the size of the ocean.  Sea life hitches rides and appropriates this trash for camouflage etc..  Small impact related to surface temperature perhaps?  Possible resistance to wave propagation from Hadley downwelling or dilution of eddy transport?  Whatever impact it may have is certainly unique to this current climate.

[Artful Dodger]

The next ENSO Diagnostics Discussion is scheduled for 7 March 2013.

Indeed, the new ENSO discussion is out:

7 March 2013

ENSO Alert System Status: Not Active

Synopsis: ENSO-neutral is favored into the Northern Hemisphere summer 2013.

During February 2013, ENSO-neutral continued although SSTs remained below average across the eastern half of the equatorial Pacific Ocean (Fig. 1). The Niño 3.4 index remained near -0.5oC, while the Niño 3 index became less negative as the month progressed (Fig. 2). The oceanic heat content (average temperature in the upper 300m of the ocean) similarly increased during the month (Fig. 3), largely due to the eastward push of above-average temperatures at depth (Fig. 4). The Madden-Julian Oscillation (MJO) again contributed to increased atmospheric variability over the tropical Pacific during February. Anomalous low-level winds were primarily easterly over the west-central equatorial Pacific, while upper-level winds remained near average, but with some intra-monthly variability. Over Indonesia, anomalous convection remained enhanced north of the equator and suppressed south of the equator (Fig. 5). Due to the lack of persistent atmosphere-ocean coupling, the tropical Pacific continues to reflect ENSO-neutral.

...ENSO-neutral is favored into the Northern Hemisphere summer 2013

...The next ENSO Diagnostics Discussion is scheduled for 4 April 2013.

[Artful Dodger]

Following this mornings posts, I checked the SST global maps. They don't tell much about heat content in the deeper layers. But some interesting differences with last year speak out on the maps.

Hi werther,

Please look at Fig.3 from the March 7, 2013 ENSO Diagnostic Discussion. It shows the oceanic heat content near the equator (average temperature in the upper 300m of the ocean) for the Eastern Pac (180W to 100W).

[Tim King]

Was not the weather memory of the previous La Nina been fairly persistent in the run up the the still born El Nino across the Pacific Basin? Then what caused this pattern?  The anomalously high ss temps in North Atlantic Equatorial region maybe caused by relatively weak NAO in second half of winter causing reduced trade wind cooling.  It will have an input into tropical storm development in that area from African waves but their development into hurricane strength is often limited by Saharan dry air. If this happens the surface is not mixed so much and carries that extra warmth towards the Gulf of Mexico and the Western Atlantic to positively influence hurricane formation their and to potentially bring exta heat to the melting of the GIS.

[werther]

Well, I'll be ***... You just read CPC's march prediction... and then you get this from OSDPD. Just compare it to 0403 above... this is Nino-pattern unfolding. Do we see the oceans regressing into a sort of Parkinson "on-off" effect? Sure you can call this 'La Nada', but it's not like nothing is going on...

[Neven]

BOM is updating its ENSO wrap-up tomorrow, I guess tonight for us Europeans.

[crandles]

Just three days ago there were 6 red lines above 0.5 on
http://origin.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/imagesInd3/nino34Sea.gif

This is a rapid movement downwards.

(see http://origin.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/imagesInd2/nino34Sea.gif for what it was like on 27th March.)

OTOH
http://origin.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/imagesInd1/nino34Sea.gif
seems to be showing red lines below zero that will soon be replaced by blue lines perhaps like other blue lines above zero. So there was a rapid change upwards a short while ago which has now evaporated.

Is this normal in the run up to the spring forecast barrier? Perhaps when ENSO is neutral the spring barrier creates a bigger problem and more rapid swings in enso forcasts?

[deep octopus]

Hi folks,

Long time follower/lurker/reader, just joining. I've been following ENSO developments with much interest the past few months. Like Werther, I've also lately been observing the warming of the equatorial Pacific waters west of South America.

Indeed, Nino 3 and Nino 1+2 region SST anomalies have flipped slightly positive again and (based on previous El Niño/La Niña episodes) can be a leading indicator of Nino 3.4 SSTs that NOAA uses to determine if an event is occurring.
http://www.cpc.ncep.noaa.gov/data/indices/wksst8110.for

And, yes, there appears to be some warmth sitting in deeper waters, which could well rise to the surface in the next few weeks.


And the underwater currents (Kelvin Waves?) are aggressively pushing eastward at the equator, so the pool of warm water in the western Pacific is very clearly finding its way to the east.


Trade winds have also been slackening the past few weeks in that same Nino 3 region, so there could be potential for positive feedbacks that would bring El Niño back into play.

[Steve Bloom]

Re ENSO and related changes, several recent papers to look at:

Are greenhouse gases changing ENSO precursors in the Western North Pacific?
http://cliserv.jql.usu.edu/paper/JCLI_WNP_ENSO_final.pdf

Recent multidecadal strengthening of the Walker circulation across the tropical Pacific
http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate1840.html

A change in the relationship between tropical central Pacific SST variability and the extratropical atmosphere around 1990
http://iopscience.iop.org/1748-9326/7/3/034025/article

Sorry, abstract-only for the second one.  I've requested a copy.

[Artful Dodger]

Re ENSO and related changes, several recent papers to look at:

Are greenhouse gases changing ENSO precursors in the Western North Pacific?

Hi Steve, welcome to the Forum 

I'm trying to cast a slightly wider net here, looking for evidence of a teleconnection between ENSO and Arctic sea ice/boreal climate change. Something more along the lines of these:

Gong, Dao-Yi, et al. "Interannual linkage between Arctic/North Atlantic Oscillation and tropical Indian Ocean precipitation during boreal winter." Climate Dynamics (2013): 1-21. PDF

Zhang, Renhe, et al. "Effects on Summer Monsoon and Rainfall Change Over China Due to Eurasian Snow Cover and Ocean Thermal Conditions." (2013). PDF

[Neven]

BOM is updating its ENSO wrap-up tomorrow, I guess tonight for us Europeans.

BOM has updated:

Atmospheric and oceanic indicators of the El Niño-Southern Oscillation (ENSO) generally continue within the neutral range. The recent increase in the Southern Oscillation Index (SOI) has been due to persistent high pressure weather systems in the central Pacific Ocean, and is not considered indicative of the broadscale climate. The SOI is known to be volatile at this time of year.

Summer ocean surface temperatures around Australia were the highest on record. Some cooling of the ocean off Australia’s northern coast has taken place in the last fortnight, in association with tropical cyclones Sandra and Rusty, but southern waters remain warm. High ocean temperatures may promote increased local rainfall in favourable weather conditions.

Climate models indicate the tropical Pacific is likely to remain ENSO-neutral through the first part of the southern hemisphere autumn. While it is known that predictions from dynamical models during the April through June period have lower skill, all models agree that an ENSO-neutral state is the most likely scenario for the next season.

The Indian Ocean Dipole (IOD) has little influence upon Australia’s climate from December through to April.

[Vergent]

NOAA has changed how they detrend the index.

http://www.climatewatch.noaa.gov/article/2013/in-watching-for-el-nino-and-la-nina-noaa-adapts-to-global-warming

Since ENSO events are identified by temperatures that are warmer or cooler than average, the key question is: what’s average? Up until last year, Climate Prediction Center scientists used a 30-year average of the three most recent complete decades, updated in each new decade. So, in the 1990s, for example, they used the 1961-1990 average, and in the 2000s, they used the 1971-2000 average.

.....

To deal with the reality of climate change, Climate Prediction Center scientists decided, after brainstorming with colleagues at the International Research Institute for Climate and Society, to start using fixed 30-year averages. Each five-year period in the historical record now has its own 30-year average centered on the first year in the period: the years 1950 to 1955 are compared to the 1936-1965 average, for example, while the years 1956-1960 are compared to 1941-1970.

This approach works smoothly up through the 1996-2000 period, which uses the 1981-2010 average. However, the 2001-2005 period will require the 1985-2015 base period, and 2006-2010 will need the average from 1991-2021. Until those years are available, CPC will use the most recently calculated climatology, which, for now, is the 1981-2010 average. They will update the climatology every five years. The next update will be in 2016, at which point the average for calculating La Niña and El Niño for the current decade will shift to the 1985-2015 period.

The new approach essentially changes from a 30+ year trailing mean to a now centered mean, This subtracts between 0.1-0.2C from the index.



Under to old method the El nino would have been longer and stronger.

[Glenn Tamblyn]

You all might find this interesting

It is Meehl et al 2011.
http://www.nature.com/nclimate/journal/v1/n7/full/nclimate1229.html - the link through Google Scholar for the full pdf is broken unfortunately.

Essentially that some climate models predict that hiatus periods will occur from time to time, typically lasting a decade or so, where more heat gets transported to the middle depths of the ocean and less remaining nearer the surface. Which is what we are seeing recently in the OHC data 0-2000 vs 0-700. This covers all the oceans not just the Pacific and depths down to 2000 are greater than the depths involved in ENSO.

So a possible scenario. A broader scale hiatus period is occurring at present, transporting more heat deeper. This is on a larger depth/distance scale than ENSO, potentially across multiple basins but may well be interacting with ENSO in the South Pacific basin. If the oceans are tending to drive heat deeper, could that be having a local effect in the South Pacific, tending to draw the heat that might rise during an El Nino deeper, countering the forces leading to El Nino's and producing a higher proprtion of La Nina's?

Could this also be a factor in the current 'Warming has stopped' denialist meme. Warming of the upper ocean certainly has been slower in the last decade even if total ocean warming hasn't slowed. But if the surface waters don't warm as much, the atmosphere won't either.

[Artful Dodger]

You all might find this interesting

It is Meehl et al 2011.

Thanks Glenn. The PDF is here:

Meehl, G. A., J. M. Arblaster, J.T. Fasullo, A. Hu and K.E. Trenberth 2011 Model-based evidence of deep-ocean heat uptake during surface-temperature hiatus periods, Nature Climate Change, 5pp, DOI: 10.1038/NCLIMATE1229.

I'd sure appreciate it a squid could leak some cruise data. THAT would be a silent service. 

[Bruce Steele]

ASLR has pointed out the formation process changes for AADW at the Antartic page. The last line of the Meehl paper posses questions which further ARGO work may help resolve.  " Whether the processes noted here are intrinsically linked through phenomena such as ENSO-like or Interdecadal Pacific Oscillation teleconnections or whether it is a coincidence that oceans change together to play a role in creating the hiatus periods warrants further exploration." I will be interested in how the PDO (Interdecadal Pacific Occillation) plays into all this.

[Glenn Tamblyn]

New paper on OHC and its vertical distribution has just come out. Involvement of the 1998 El Nino considered but a big impact from the volcanic eruptions, particularly Mt Pinatubo in 1992

http://thingsbreak.files.wordpress.com/2013/03/distinctive-climate-signals-in-reanalysis-of-global-ocean-heat-content.pdf

Warming hasn't stopped, it has accelerated!

[werther]

Thanks, Glenn,
From the "Distinctive climate signals in reanalysis of global ocean heat content", Balmaseda Trenberth Källén 2013.
I found this that stirs me:

'More surprising is the extra cooling following 1998, a likely consequence of the ocean heat discharge associated with the massive 1997–98 El Niño event [Trenberth et al., 2002]. Meehl et al., [2011] have demonstrated in a model study how La Niña events and negative PDO events could cause a hiatus in warming of the top 300 m while sequestering heat at deeper layers. This mechanism can also explain the increasing role of the depths below 700m after 1999 in the ORAS4 OHC, consistent with La Niña-like conditions and a negative phase of the PDO which has dominated the last decade. The deep ocean warming, which mostly involves the depth range 700–2000 m, and may also be related to the weakening of the MOC after 1995, which is present in ORAS4 [BMW13]. Possibly changes in MOC and PDO are connected by changes in the atmospheric circulation patterns.'

[Glenn Tamblyn]

Yeah Werther.

The oceans really are the dog of climate. Everything else is just the tail wagging.

[AndrewP]

I don't see the big deal. All ENSO events are unique. Not all developing El Ninos go on to become full-fledged moderate or strong El Ninos. El Nino events are preceded by a build up of 0-300m OHC in the tropical pacific. The OHC that built up over last summer was not really very impressive for an El Nino. IIRC most forecasts were for a weak El Nino. But then OHC began to tank in September.


If you want to look for what killed this El Nino, I'd look at September. At the start of the month 0-300m tropical pacific temperatures were .8C above average. By the end of the month they were only .2C above average. That's a TON of heat.

[dorlomin]

Speculative question alert! Would the rapid inudtrialisation of S+SE Asia, specifically Indonesia but also India and China not likely see a regional build up of sulphates that would reduce the rate of warming in the West Pacific Warm Pool, hence reduce the warm phase of the ENSO?

[werther]

Hello Dorlomin,
As the western warm pool has been pointed at as possibly fuelling the recent SSW events, I would be surprised if industrial emittance would have the effect you mention. For March, NCEP/NCAR doesn't hint at that too:



The teleconnective lead thats maybe even harder to prove is partly in the intense pressure/temperature anomalies, like over the NH through March:



I'm not suggesting that ENSO hasn't wobbled in the past. There were long 'neutral' periods then, too. But the timing and strength of the variability does suggest a relationship.

(PS I've renewed this post, as I saw it's no use copying an URL straightaway from the Daily composites. So I interfaced via Photobucket again...)

[deep octopus]

Trade winds on the eastern Pacific are now significantly weaker this month than in February.

https://lh5.googleusercontent.com/-qwACHTMc6dQ/UVWqxELaIdI/AAAAAAAAACw/0djvDPve3LE/s799/compday.50.198.155.157.87.8.51.29.gif


Currents along the equator also continuing to make a strongly eastward push.


And Niño 3 SST's continue to climb higher in-kind.



Given this, I wouldn't rule out that a 2013-2014 El Niño in the making. Just some things to keep an eye on.

[Artful Dodger]

Given this, I wouldn't rule out that a 2013-2014 El Niño in the making. Just some things to keep an eye on.

Indeed Deep Octopus, it will be interesting to read the NOAA forecast this coming Thursday:

The next ENSO Diagnostics Discussion is scheduled for 4 April 2013.

BTW, are there a couple dolphins above your left breast pocket?

[deep octopus]

Ha! Why yes, but as somewhat of a mesopelagic animal, I usually have to swim to the surface to find them there whenever I need help from them.

Some more tips from my Pacific dolphin friends, who are reporting warmer water this week than last. Formation of a warm tongue is more apparent today than it has been in months, if the daily NCDC SST map is anything to respect. The warm tongue has clearly moved over the Nino 3.4 region, which is what NOAA uses to identify El Niño.


Tomorrow's ENSO update should be revealing, indeed. I'm imagining that if this trend can be self-sustaining and intensify for a few more weeks, the atmospheric-ocean synergy will kick in, pointing to a greater than 50% chance of El Niño. And from that, 2014 would be well-positioned to overtake 2010 as the hottest year globally. But like watching Arctic ice, it all depends on keeping a patient and watchful position.

[Artful Dodger]

Hi D/O. Useful friend, that little ELF... 

The NOAA ENSO update was released on April 4, 2013:

Most models forecast Niño-3.4 SSTs to remain ENSO-neutral through the Northern Hemisphere fall (Fig. 6), with dynamical models tending to predict warmer conditions (0oC to 0.5oC) than the statistical models (-0.5oC to 0oC). There is less confidence in the forecasts for the last half of the year, partly because of the so-called "spring barrier," which historically leads to lower model skill beginning in late spring.

The next ENSO Diagnostics Discussion is scheduled for 9 May 2013.

[Steve Bloom]

Just happened to spot this interesting EGU poster:

The effect of the stratosphere on the Boreal response to Pliocene-era tropical Pacific sea surface temperatures

Manoj Joshi (1) and Chris Brierley (2)
(1) School of Environmental Sciences, University of East Anglia, Norwich, UK, (2) Department of Geography, University College London, London, UK

Previous work has shown that the stratosphere modulates the Northern Hemisphere response to equatorial Pacific temperature anomalies associated with the El Niño Southern Oscillation. Here, we show that the stratosphere also plays a major role in modulating the response to tropical sea surface temperature anomalies representative of the mean state of the Pliocene era, approximately four million years ago. Changes in the occurrences of so-called sudden stratospheric warmings during Boreal winter and spring force a significant anomalous surface pressure response over the North Atlantic Ocean. The anomalous circulation pattern results in relatively cold winter-spring Eurasian surface temperatures and relatively warm surface temperatures in Greenland and North America. The implications of these results for simulating and understanding the climate of the Pliocene era 4 Myr ago are discussed.

http://meetingorganizer.copernicus.org/EGU2013/EGU2013-10882.pdf

Sounds not entirely inconsistent with present trends. 

[crandles]

Continues to be unpredictable it seems:

MEI neutral on La Nina side:
http://www.esrl.noaa.gov/psd/enso/mei/table.html

CFSv2 spiked into el Nino territory
http://origin.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/imagesInd3/nino34Sea.gif
albeit only a short period above .5 SD.

[Jim Williams]

Continues to be unpredictable it seems:

MEI neutral on La Nina side:
http://www.esrl.noaa.gov/psd/enso/mei/table.html

CFSv2 spiked into el Nino territory
http://origin.cpc.ncep.noaa.gov/products/people/wwang/cfsv2fcst/imagesInd3/nino34Sea.gif
albeit only a short period above .5 SD.

And here we are at "the Spring Wall."  The projections of the forecasts mean nothing at all at this time of year.

[misfratz]

Speculative question alert! Would the rapid inudtrialisation of S+SE Asia, specifically Indonesia but also India and China not likely see a regional build up of sulphates that would ... reduce the warm phase of the ENSO?

There is some evidence that sulphate aerosols from North America were responsible for shifting the ITCZ in the tropical Atlantic having a knock-on impact on Sahel rainfall, leading to the persistent series of droughts there in the 70s and 80s.

It is plausible that Chinese and SE Asian aerosols might also have an impact on the tropical Pacific, though I'd be wary of speculating about the mechanisms involved. I think there are some non-core experiments in the CMIP5 plan for model runs with aerosols off, so by comparing those with the standard runs you would be able to look for an impact on ENSO - though really you'd want an experiment with just the SE Asian emissions of aerosols tweaked.