ENSO Updates (2007 thru 2023)

[Hunabku]

I put together an animation to better conceptualize the connection between PDO and ENSO, via ONI which uses 3.4 region.

In the bottom area, the PDO looks 3.5 month into the future from the current date of the animation. I went with a 3.5 month PDO lag because it tracked closer to ONI than 3 or 4 months with this data set. Since we don't have October's JISAO PDO data yet, I estimated that it will stay the same as September's. On the "Lag Differential .." chart in the lower right, notice the big jump in the differential between PDO-October and ONI-June (the last big red bar).

This jump could be because of any one or a combination of the following:
1) There is something outside of ENSO teleconnection that has been recently forcing the PDO more positive
2) The PDO is showing a stubbornness to go lower which means more nino trends going forward
3) My October estimate for PDO is high, so it will actually be lower, which would better track with ONI

Also notice toward the end of the animation in November with the cold deepening in the east pacific. This seems to portend a dropping PDO, which will bring it more back in line with the temps that have dropped in ONI since July.

One thing to think about is the depth of the warm waters in the far northeastern Pacific above 40N. For the past couple of years it's not just shallow surface warmth easily shifted by the upper level pattern but consistent at depth as well. It takes a lot to upwell cooler waters with such deep warm anomalies. I think had the Nina been able to go stronger the atmosphere may have been more successful at flipping the PDO but instead the weather pattern in the northern Pacific remained similar to as if ENSO was a Nino with the deeper Aleutian low.

Anomalies at depth in the northeastern Pacific. The area you want to look at is right of 40N on this chart.



Quite warm in fact up and down the latitudes across the eastern Pacific. I posted Sept because ECMWF reanalysis does not yet have data for October.

In your typical cold PDO at depth would be colder

Wonderful thanks for this. I'd like to explore other corollaries besides Sept 2012, which was a strongly negative and entrenched PDO. If I may ask - where did you find these subsurface temp maps at?

[Ntxw]

They can be found in the ECMWF (euro) reanalysis. It's a great resource

http://www.ecmwf.int/en/forecasts/charts/oras4/

Meridonial monthly average is what I used for this case

[Ntxw]

-0.7C this week.

More on the PDO. In fact if you take the traditional NPAC PDO area (20N and up), you could make an argument the +PDO is strengthening for November!

+PDO to the left

[Hunabku]

-0.7C this week.

More on the PDO. In fact if you take the traditional NPAC PDO area (20N and up), you could make an argument the +PDO is strengthening for November!

Ha I see your point - that would be something.

[Hunabku]

@Ntxw

This from http://www.aer.com/science-research/climate-weather/arctic-oscillation

But the big story of late has been the rapidly cooling SSTs across the mid-latitudes of the North Pacific. These cool waters seem to be a result of the very cold temperatures that developed across Siberia this October. The cold air across Siberia both being advected out across the North Pacific and strengthening the westerlies across the North Pacific have dramatically cooled SSTs in the North Pacific. This seems analogous to the winters of 2013/14 and 2014/15 when cold temperatures in Canada cooled North Atlantic SSTS and strengthened the Jet Stream to record speeds as it headed towards Europe. This dramtaic cooling of SSTs demonstrates we are more confident that the atmosphere forces SSTs than SSTs force the atmospehre in the mid-latiudes. Warmer than normal SSTs to the north near Alaska and colder than normal SSTs across the mid-latitudes, could favor a southward shift the in the Jet Stream across the North Pacific this winter. The cool waters across the mid-latitudes could help strengthen the Aleutians low further south opposite to what might be expected during La Niña.

Edit: In my nullschool mashup graphic below, you can see how winds from yesterday's Aleutian low push colder air/water and hence SST anomalies south while pulling up warmer air/waters along the west coast US - thus bumping up the PDO signal when it should be dropping now. Interesting to see how south the Aleutians low go, that mid-latitude of the North Pacific sure is anomalously cold.



Seems like changes in NH upper latitudes are creating a dominant weather forcing mechanism that is more and more consistently drowning out the ENSO signal.

[Ntxw]

@Ntxw

This from http://www.aer.com/science-research/climate-weather/arctic-oscillation

But the big story of late has been the rapidly cooling SSTs across the mid-latitudes of the North Pacific. These cool waters seem to be a result of the very cold temperatures that developed across Siberia this October. The cold air across Siberia both being advected out across the North Pacific and strengthening the westerlies across the North Pacific have dramatically cooled SSTs in the North Pacific. This seems analogous to the winters of 2013/14 and 2014/15 when cold temperatures in Canada cooled North Atlantic SSTS and strengthened the Jet Stream to record speeds as it headed towards Europe. This dramtaic cooling of SSTs demonstrates we are more confident that the atmosphere forces SSTs than SSTs force the atmospehre in the mid-latiudes. Warmer than normal SSTs to the north near Alaska and colder than normal SSTs across the mid-latitudes, could favor a southward shift the in the Jet Stream across the North Pacific this winter. The cool waters across the mid-latitudes could help strengthen the Aleutians low further south opposite to what might be expected during La Niña.

Edit: In my nullschool mashup graphic below, you can see how winds from yesterday's Aleutian low push colder air/water and hence SST anomalies south while pulling up warmer air/waters along the west coast US - thus bumping up the PDO signal when it should be dropping now. Interesting to see how south the Aleutians low go, that mid-latitude of the North Pacific sure is anomalously cold.

http://i.imgur.com/ZI9tHd3.png

Seems like changes in NH upper latitudes are creating a dominant weather forcing mechanism that is more and more consistently drowning out the ENSO signal.

It's no secret the Aleutian low is a reflection of El Nino. During +PDO/El Nino episodes the aleutian low is very strong thus cooling the waters by upwelling it below the Aleutians. During La Nina the Aleutian low is significantly weaker and often replaced by the Aleutian high shoving the lower pressures east towards the coast of North America and you have a -PDO look. So while the tropics have seen some La Nina like weather patterns, the mid latitudes are still lagging. Perhaps still feeling the effects of the monster El Nino of past.

however if you look back at those SST's maps the waters just west/northwest of Hawaii is very warm which is more typical of La Nina/-PDO. I think by early next year perhaps this area of warmth will shift northeastward and perhaps change the PDO but it is a very, very slow process. But as of right now the +PDO looks to be holding on through the last 45 days or so of the year.

[Hunabku]

PDO decoupling from 3-4 month ENSO lag signal, or intensifying as to indicate more nino-like trends in the future? I'd guess more of the former, because of the degree of positive change. Interesting to see if the trend persists. Disclaimer - this graph is using all ENSO regions (not just 3.4)

Also found this on PDO Wikipedia site:

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.

With all that said, i could see how what we are seeing currently with the SST cooling in mid latitudes might be due to more to Ekman pumping and to a lesser extent the cold Eurasian air mass transport.

Edit: Hmm - kinda of rethinking that just looking at how that cold Eurasian air intrudes over the last 72 hours.

[Ntxw]

Jisao PDO for October nudge up to 0.56. With Nov half way done and no sig changes through the rest of this month, Nov's reading will jump up even more. 1983-1984 had a similar disconnect between -ENSO and +PDO

[Ntxw]

Both CFS and Euro (very very early) are hinting at the return of warm ENSO (El Nino?) By next spring. It is way to early to speculate but with the rise in PDO it is food for thought

[Hunabku]

Both CFS and Euro (very very early) are hinting at the return of warm ENSO (El Nino?) By next spring. It is way to early to speculate but with the rise in PDO it is food for thought

Yes rise of the PDO does give credence to warming by next spring. But notice that in late '83 the high PDO did not translate into nino conditions by spring of '84.


I think that the reason why late '83 deviated so much from the more typical PDO 3-4 month ENSO lag is the same reason why we are deviating so much now - namely the presence of the Aleutian low and the primary long-term index that quantifies its presence, the North Pacific Index (NPI).

Bob Tisdale explains https://bobtisdale.wordpress.com/2014/04/20/the-201415-el-nino-part-5-the-relationship-between-the-pdo-and-enso/

That (NPI) causes the year-to-year and the multidecadal variations in the PDO index to be different than an ENSO index. . . . the differences in the multidecadal variations between the PDO index and our ENSO index can be seen in Figure 4. (below)

I subtracted the PDO index data from standardized NINO3.4 sea surface temperature anomalies, and compared that difference to the North Pacific Index data, where the difference and the North Pacific Index data were both smoothed with multiyear filters. The long-term variations mimicked one another reasonably well over much of the term of the data.

Perhaps a better question to ask is: If the NPI wasn't having such a powerful effect on the PDO now, how high would the PDO be? I still think that the models are going in the right direction in regard to an ENSO warming trend into spring, especially when I look at SSHA surrounding ENSO regions and the fact that the atmosphere hasn't yet built up enough indication or momentum to really drive a significant nina state. With that all said there is decent coldness in 3.4's thermocline and all we need are some trades.

Also, i put the new October PDO value you provided into my spreadsheet and the difference between october's positive PDO and ONI (3.5 months before october) jumped up even further to .63. Big deviation there.

[Ntxw]

The colder North Asia and cooling of the Pacific (via the gradient) is a common occurance during El Nino. A typical Nina/-PDO should actually be warmer in Asia and cooler over North America

Fall composite of Nino's

[cycloneye]

 https://twitter.com/philklotzbach/status/799327420415283200

[NDG]

Euro has not done too well with its ENSO forecast over the past 6 months or so in its shorter 1-4 month range, first it was forecasting it to cool down too fast then forecasting it to warm up back to neutral levels by now.

[Ntxw]

Warms a little more to -0.4C this week

[Golf7070]

Does anyone have all the region numbers for enso? Beside 3.4?

[Ntxw]

Does anyone have all the region numbers for enso? Beside 3.4?

You can get all ENSO data from the CPC ENSO page. latest update

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

Code: Select all

Niño 4 -0.3ºC
Niño 3.4 -0.4ºC
Niño 3 -0.3ºC
Niño 1+2 -0.1ºC

[Hunabku]

Even though the ENSO indexes are similar between 1997-98 and 2015-16, we see a significantly more powerful moisture signal in 2015-16, in large part due to global warming and the greater capacity of warmer air to carry water.



I also think that all the anomalously warm pacific waters outside of ENSO regions mightily fed into this boom of moisture and amplification of the Hadely Cell. That amplification caused the rain to push way north of southern cal and deliver unprecedented nino rain to the pacific northwest.

Lots of super cool research going on around all this right now, including connections to other atmospheric processes such as the polar cell and the QBO.

[Ntxw]

-0.4C again this week. After calling for a Nina, then putting it off, and then back on, and now unless it strengthens which is looking less likely (in fact warm anomalies are starting to develop out in the central Pacific below the surface) CPC may not get enough for an official Nina.

The CPC took a very cautious approach with the 2014-2015 weak El Nino and didn't declare anything until it was official that there were enough ONI values by Feb to call it. Yet for this Nina with weaker support and the on and off nature they've been more bullish on it. I thought they would have taken the same cautious approach. Kind of a head scratcher there.

[Ntxw]

I don't think this still qualifies as a La Nina. Doesn't appear like there will be enough trimonthlies.



In fact with recent warming trends of the ENSO regions, one might actually think we could end up with warm neutral weekly values by the end of winter.



+PDO and the atmosphere put a kibosh on the event

[wxman57]

See this discussion of how Pacific SST anomalies are being modified to indicate warmer conditions there (La Nina) when it appears that neutral conditions prevail:

https://wattsupwiththat.com/2016/12/05/early-december-2016-la-nina-update-mixed-signals-from-noaa-and-bom/