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Saturday, September 10, 2016

Losing his grip on ENSO: Bob Tisdale thinks he's an expert, and yet...

Sou | 3:57 AM Go to the first of 14 comments. Add a comment
Bob Tisdale fancies himself as an ENSO expert, yet he doesn't show that in his WUWT article today (archived here). He's complaining that a couple of days ago NOAA removed the "watch" status for La Nina. Bob's headline was "NOAA Cancels La Niña Watch While La Niña Conditions Exist". Well, he seems to be the only person who thinks La Nina conditions exist. Oh, except maybe for Anthony Watts who, way back in June, declared that we are already having a La Nina.

Today Bob Tisdale wrote:
Regardless of the existing (and strengthening) La Niña conditions, NOAA has canceled its La Niña Watch, which had been in effect since April.
Except there are not conditions currently existing for La Nina. Bob's wrong. This is where he was wrong - almost everywhere:
  1. Bob didn't base his assessment on the ENSO definition's standard of the ONI, which is a 3 month running mean;
  2. He based his current sea surface temperature anomaly in the Nino 3.4 region on the wrong average baseline, making it appear approx 0.4 C colder than it is (the cutoff is -0.5 C) (h/t Rattus Norvegicus);
  3. He used the wrong dataset (Reynolds OI v2), not the one used as standard for ENSO estimates (ERSST v4).
Summary added by Sou 4:57 pm 10 September 2016

What seems to have happened is that Bob got the definition of La Nina wrong, which surprises even me. He wrote:
La Niña conditions are typically defined by NOAA as sea surface temperature anomalies less than or equal to -0.5 deg C for the NINO3.4 region of the east/central equatorial Pacific. 
Different agencies have different definitions for the conditions required for La Nina. They share some of them, such as that "During La Niña events, there is a sustained strengthening of the trade winds across much of the tropical Pacific". Currently the trade winds are fairly normal - not characteristic of La Nina. BoM reports:
Trade winds near the equator in the Pacific Ocean have remained close to average for the 5 days ending 28 August, and have remained generally so since March.



Contrary to what Bob wrote about NOAA, that agency defines La Nina in terms of the Oceanic Nino Index. That's the three month running mean of the sea surface temperature in the Nino 3.4 region, not the temperature anomaly at any one time. Because of global warming, sea surface temperatures are increasing, so NOAA adjusts the base period for the ONI every five years. The current base period is 1986 to 2015. This is explained on the NOAA website:
...ONI values during 1950-1955 will be based on the 1936-1965 base period, ONI values during 1956-1960 will be based on the 1941-1970 base period, and so on and so forth.

In real-time operations, the past 30-year base period (e.g. 1986-2015) will continue to be used to compute the departure from average. However, CPC will create an additional 30-year base period every 5 years (the next update will be at the beginning of 2021).. When these 5 year updates occur, the ONI values over the most recent decade will change slightly because of the inclusion of more recent data.
What that means is that even with the most recent warming factored in, the ONI still isn't at La Nina threshold levels. (If an older base period had been used it would be even further from the threshold.) The current and past ONI values are shown here. For the most recent three month running means, the values are as follows:
  • AMJ 0.6 (April, May, June)
  • MJJ 0.1 (May, June, July)
  • JJA -0.3 (June, July, August)

So it's not at -0.5 C 3-month running mean yet, and the chances are getting higher that it won't make it, according to NOAA.

The BoM ENSO update is always available in the sidebar. Although it's had a La Nina watch for some time, for most of that time the BoM reports have indicated that if we get one (and the chances it gave were at best 50/50) then it was likely to be weak. The latest report was the weakest of all. The next report is due next Tuesday so it will be interesting to see what it says.

Incidentally, BoM uses the Southern Oscillation Index (SOI) as a measure of ENSO, as well as other indicators such as the strength of the trade winds, sea surface and sub-surface temperatures. For the SOI:
Sustained positive values of the SOI above +7 typically indicate La Niña while sustained negative values below −7 typically indicate El Niño. Values between about +7 and −7 generally indicate neutral conditions.
Here is the BoM model outlook from 31 August 2016. Most of the model runs show that the Nino 3.4 sea surface temperatures have bottomed and are expected to rise:


I can understand the deniers' disappointment that La Nina isn't bringing the expected ice age. While there's still a chance of a La Nina this year, it's looking less and less likely.


From the WUWT comments


In among the comments from rational people, there were the usual from the conspiracy theorists. Dr. S. Jeevananda Reddy is one such person who seems sure that a La Nina is on its way and the scientists are conspiring to hide the fact:
September 9, 2016 at 3:52 am
ENSO nuetral condition means, the temperature anomaly must be flat with ups and downs. At present no such scenario is evident but on the contrary the El Nino peak coming down steadily, a La Nina condition similar to 1997/98. Unfortunately science is misused for the selfish gains, There is a strong need to stop such tendencies in scientific institutions.
Dr. S. Jeevananda Reddy

tadchem is another conspiracy theorist, though I've no idea to what he's referring:
September 9, 2016 at 5:47 am
Never let the data get in the way of a politically productive hypothesis.

Clyde Spencer  is another one. His reasoning is not reasonable. Remember that until this week, NOAA was reporting a La Nina watch, so Clyde's comment makes no sense.
September 9, 2016 at 9:01 am
Kevin,
NOAA thought it worthwhile reporting. I suspect that is part of the intention to scare the public with reports of high temperatures with little chance of declining. The problem is, if their forecast turns out to be wrong, they will have egg on their face.

Our new fan ptolemy2 must be looking in the wrong place, putting up an old chart at WUWT. I'll give him or her a helping hand - and for future reference the entire archive.
September 9, 2016 at 8:04 am
Can anyone say why the BOM monthly subsurface Pacific ocean equatorial temperature anomalies down to 400 meters, has stopped at March 2016:
It took a good couple of hours before anyone realised (or commented) that Bob had his criteria wrong. It was Kevin in NH who first pointed this out:
September 9, 2016 at 6:08 am
I think the official designation for La Nina would be 3 consecutive months or more with -0.5C anomalies or colder.
#1 This makes any declaration of La Nina (or El Nino on the other side) overdue as it is not official until it has been going on for at least 3 months.
#2 Most of the recent forecasts I have seen show the anomaly hanging out just about at 0.5C for a couple of months then returning very close to zero, not a steep, long lived drop into Nina territory.
So yes the conditions exist right now but may not make the 3 month threshold.
And “global warming” is NOT the cause of a huge Nino not turning into a huge Nina.

A little while later Richard M pointed to another problem with Bob's unfounded claims:
September 9, 2016 at 6:33 am
The problem is the trade winds have yet to pick up. Since they normally don’t start doing this during the NH summer I’m not sure what the NOAA changes are based on. If the models are based on those summer winds then their ability to predict La Nina will not be very good.The issue will be what happens in October and thereafter.

Perpetually joyfilled (some might say perpetually hysteric) Janice Moore was quite overwhelmed, as usual, with Bob's cleverness:
September 9, 2016 at 9:29 am
Thank you, Bob Tisdale — for more GREAT analysis. What a gift to the world you are: a true humanitarian in your persevering efforts to get the facts out there.
How was your first long holiday in YEARS (if I am not mistaken)? I hope that it was wonderful.
Janice

Top image source: Bureau of Meteorology 




14 comments:

Victor Venema said...

Even if you see lizard people everywhere and are gullible enough to know there is a global conspiracy in a natural science over decades, why the hell would anyone try to make this La Nina smaller? El Nino is just noise on a long-term trend.

If they would want to start their "hiatus" nonsense all over again, they should be thrilled that the start of their 2016 hiatus is warm. They would need La Nina's at the end of their "hiatus", now they need warmth.

seaice said...

What I do not understand bout WUWT is that they deny things that need to maintain their story. When the Godzilla El Nino was predicted they were denying that the coming El Nino was exceptional, yet when temperatures rose they relied on an exceptional El Nino to explain the temperatures. This is similar. They need the La Nina to fail in order to explain the lack of cooling that will presumably happen. I can see it now - temperatures did not fall because there was no La Nina like there was in 1999. It appears to be just a knee jerk rejection of anything that scientists say about the climate.

It reminds me of Trump. It doesn't matter if he is caught out in a lie because there are simply too many to tie him down to.

Rattus Norvegicus said...

It also appears that he used a more recent base period in his cute little lying chart, 1990-2016. I caught the 3 month running mean error, but didn't know about the base period used to define what the 0C anomaly is.

Rattus Norvegicus said...

It also appears that he used a more recent base period in his cute little lying chart, 1990-2016. I caught the 3 month running mean error, but didn't know about the base period used to define what the 0C anomaly is.

@whut said...

Lots of interesting papers on ENSO over the years, some of these are obscure in spite of the credentials of the authors. I reviewed Glenn Brier's work from 1989 here

My understanding is that ENSO will become predictable soon.

Sou said...

Good catch. I missed that one. I put down the difference to Bob's choice of dataset, which isn't the one used by NOAA (or any agency) for ENSO estimates. I should have checked.

Nick said...

Tisdale is so numbingly arrogant. It is trivially easy to check on his claims. The classification criteria are clear.

Nick said...

...and this seems just neatly pitched for squeaky wheels like Bob:
https://www.climate.gov/news-features/blogs/enso/september-2016-enso-update-cooling-our-heels

Raymond Arritt said...

Glenn was my unofficial advisor for my M.S. work. He was a very gentle and modest man who had infinite patience with a rather dense beginning graduate student. Glenn died some years ago but his work still informs much of what we do now.

Anonymous said...

Declarations of ENSO "events" are based on precisely defined long-term sea surface temperature "conditions" in the 3.4 region of the Pacific Ocean. When El Nino or La Nina temperature anomalies (a "condition") in the 3.4 region are +0.5° or -0.5°C respectively, it can be said that El Nino or La Nina "conditions" exist, but an El Nino or La Nina "event" may not be present if the time (persistence) requirements have not been met.

It is easier to have a rational discussion by using more precise terms, which is why I almost always use the terms "El Nino event" or "La Nina event" vs. "conditions" when writing about the subject.

When the phrases "an El Nino" or "a La Nina" are used by meteorologists and climatologists, they generally are referring to an "event." But Tisdale is obviously talking about SST's as a "La Nina condition."

Although the latest (Sept 5,2016) NOAA "weekly Region 3.4 SST departure" is -0.7°C, it appears to have "bottomed out." The description above the NOAA graph of the model results states "The CFS.v2 ensemble mean (black dashed line) generally favors ENSO-neutral conditions during the Northern Hemisphere fall and winter 2016-2017." Indeed, the 3.4 SST line is climbing above -0.5°C and stays above that threshold until the final 3-month (MAM) on the graph. (NOAA graph uses 0.5°C tics on the y-axis rather than the odd 0.4°C tics on the above BoM graph of the same data, Sou. That makes it easier for me to see the ENSO "condition" thresholds.)

David van Harn (a.k.a. Xulonn)

Magma said...

Did Bob somehow forget that for Warmists capable of repeatedly rewriting the temperature history of the entire Earth, changing a La Nina event to ENSO-neutral is child's play? [insert evil laughter to taste]

The WUWT barrel continues to get smaller and the fish to get fatter, slower and more stupid.

Sou said...

David, the reason BoM has the "odd 0.4°C tics" and the lines on the POAMA chart at +0.8 C and -0.8 C rather than +/-0.5 C is this:

The National Climate Centre (NCC) uses the "NINO3.4 index" to classify ENSO conditions (see "Note:" below). The NINO3.4 index is defined as the average of SST anomalies over the region 5°N – 5°S and 170° – 120°W. NCC classifies the NINO3.4 temperature anomaly as "warm" if it exceeds 0.8°C, which is about one standard deviation above average.Similarly, anomaly predictions below –0.8°C are tabled as "cool", with those in between classed "neutral".

http://www.bom.gov.au/climate/model-summary/about-model-summary.shtml

NOAA uses ONI, which is a 3 month running mean at or below -0.5C.

Anonymous said...

Thanks for the clarification, Sou. I did some cursory research, and it appears that different countries (U.S.A., Australia, and Japan) use different definitions for La Nina and El Nino "events" and warm and cool anomaly ENSO thresholds.

So of course, American blogger Tisdale uses the less demanding NOAA standards, and the current -0.7°C anomaly is below the -0.5°C NOAA threshold. However, since for Bob, "all models are wrong", the ENSO neutral forecast for the coming season cannot possibly be correct.

BTW, the only background I could find on Bob Tisdale is that he is a U.S. "retiree." It appears that he has no training or education in climate science. This guy hides his identity and lack of credentials and expertise better then Tony Heller (a.k.a. Steven Goddard). I'm surprised that no one has "outed" him, because he is a prime example of a "fake expert.

David van Harn (a.k.a. Xulonn)

Sou said...

David, I don't know that NOAA standards are really any lower although I do agree that BoM is a bit more conservative when it comes to making an announcement. (ENSO events are important for much of Australia.) NOAA's -0.5 C has to be for a 3 month running mean, which means that every week it's above -0.5C there has to be at least the same time below it by the same amount.

I think the main point is that there are more indicators of ENSO events than just sea surface temperature. BoM places more emphasis on the Southern Oscillation Index (a pressure difference), and also uses all the other indicators - wind, cloudiness, sea surface temperature etc. NOAA places more emphasis on sea surface temperature, and would be guided by the other indicators as well, I expect.

One thing - the agencies agree when the event is in full swing, though they might come to that decision of when it starts at slightly different times. IIRC NOAA (and JMA) have jumped the gun on occasion.