David Middleton is hot and bothered by the spurt and the Pacific Decadal Oscillation

As you know, Anthony Watts (quite wisely) mostly uses guests to write freeby articles for his blog. He gets into too much trouble when he tries to write something all by himself. Anthony doesn't need to determine whether his guests write nonsense or not. His good friend Wondering Willis Eschenbach gave him an "out" writing: "So it is not Anthony’s job to determine whether or not the work of the guest authors will stand the harsh light of public exposure. That’s the job of the peer reviewers, who are you and I and everyone making defensible supported scientific comments. Even if Anthony had a year to analyze and dissect each piece, he couldn’t do that job..." Yes, even his close allies think Anthony's incapable of distinguishing pseudo-scientific waffle from science.

Today Anthony's posted another article by David Middleton. This time David is waffling on about the Pacific Decadal Oscillation (PDO). The PDO is measured by an index. As Kevin Trenberth explained it in a recent Perspective article in Science (my paras):

Denier Cherries: Big changes to come in climate or same old same old?

There's an article on the climate conspiracy blog, WUWT, which illustrates the tunnel vision or selective bias of deniers. It is another example of blatant cherry-picking. Eric Worrall repeated nonsense that he read on a denier website (archived here). He wrote about a recent publication from the UK Met, which has the title:

UK Met: "Changes Underway in the Climate System?"

The misleading headline at WUWT reads:

WUWT: "UK MET: Global warming pause may continue". 

That's right. Compare the two titles. The UK Met booklet is suggesting there may be big changes underway, while the WUWT article is suggesting the Met Office is saying there'll be more of the same.

Global Warming and the Pacific: Kevin Trenberth's Perspective

Earlier today, Anthony Watts copied and pasted a press release about a new article from Kevin Trenberth (archived here). Anthony, who didn't even link to the press release, complained he couldn't find the article and asked his readers to tell him where it was. Did he really want that? Or did he just pull out that press release because, for a change, he recognised the name and figured it was sure to rouse the lynch mob? Anthony wrote:

Another excuse for the pause, Trenberth says ‘Internal climate variability masks climate-warming trends’

From the  AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE and the “if warming can’t overcome Nature, is it really there at all?” department.

More "the seas got hotter because they got hotter" from Bob Tisdale at WUWT

Greenhouse effect denier, Perennially Puzzled Bob Tisdale, has written another article claiming that the seas got hotter because they got hotter (archived here). He's tried this non-argument before and didn't get hammered for it - except for here:)  Here's an image of some of the seas that got hotter this year, courtesy NOAA:

Unusually warm temperatures dominate three areas of the North Pacific: the Bering Sea, Gulf of Alaska and an area off Southern California. The darker the red, the further above average the sea surface temperature. NOAA researchers are tracking the temperatures and their implications for marine life. Source: NOAA

There's not a lot you can say about a long and tedious Tisdale article that explains that the sea surface got hotter because the sea surface got hotter. That is, the sea surface in the North Pacific got hotter - plus the sea surface over the equatorial Pacific got hotter. We already know that warming in both areas took place. In any case, it's not just the Pacific that's anomalously warm. Here is a snapshot of sea surface temperature anomalies for October, from the UK Met Office Hadley Centre.

Source: UK Met Office Hadley Centre

So, for something different let's take this paragraph from today's WUWT article and break it down. Bob wrote:

If the manmade greenhouse gas-forced climate models used by the IPCC cannot explain the 24-year absence of warming of the surface in the North Pacific, it can’t be claimed that the weather-related warming there in 2013 and 2014 were caused by manmade greenhouse gases. That little bit of common sense eludes alarmists.

The Pacific Decadal Oscillation and Australia - plus more

Here is the article about the Pacific Decadal Oscillation, with particular reference to Australia. I'll warn you in advance - it's long, a bit meandering, probably could do with more illustrations, and not a complete guide to everything. That's my excuses out of the way. I figure I've spent enough time on it so here it is. Feel free to add what you know and correct what I don't :)

In the previous article, I referred to some comments by a contributor, trying to argue that Australia's record heat of the 2012-13 summer was caused by a (non-existent) spike in the PDO index, or was an advance reaction to a spike that had not yet appeared. His comments were not easy to follow. Thing is, the PDO index wasn't positive during the Australian summer of 2012-13. In fact it did not register as positive until January 2014. There's more to it than that, in any case.

Anthony Watts takes on Kevin Trenberth and loses big time

I often wonder, as I'm sure you do, if Anthony Watts ever reads any of the articles he puts up at WUWT.  Today he's posted about an article in Nature, which in part draws on a paper by Kevin Trenberth and John Fasullo published late last year.

Thing is, Anthony has already posted a number of articles about Trenberth and Fasullo (2013).  There is this one by Bob Tisdale, which I wrote about here. And this one and this one - both also by Bob Tisdale.  Perennially Puzzled Bob Tisdale was trying to argue that Trenberth and Fasullo were cheating or something silly like that.  (Since I wrote the main article, Anthony has elevated his piece to a "sticky", which just shows what HotWhopper readers know from past experience, Anthony's memory is not that great.)

In this latest WUWT article (archived here), Anthony wrote this, as if it was the first article about the Trenberth Fasullo paper at WUWT, instead of the fourth in a just a little over a month:

From the “settled science” department. It seems even Dr. Kevin Trenberth is now admitting to the cyclic influences of the AMO and PDO on global climate. Neither “carbon” nor “carbon dioxide” is mentioned in this article that cites Trenberth as saying: “The 1997 to ’98 El Niño event was a trigger for the changes in the Pacific, and I think that’s very probably the beginning of the hiatus,”

This is significant, as it represents a coming to terms with “the pause” not only by Nature, but by Trenberth too.

For anyone who knows of Kevin Trenberth's work, to say that first second sentence of Anthony's is ludicrous would be an understatement.

Kevin Trenberth has been publishing papers about the oceans for more than forty years.  He knows more about oceans than all the purported hundreds of thousands of WUWT readers combined. John Fasullo is younger, but if you combine them, they have more than 55 person years of science between them.

If Anthony Watts is interested in tracking the history of discovery of the Pacific Decadal Oscillation, he could do a lot worse than starting with the following two seminal papers by Kevin Trenberth, going back nearly 25 years:

Trenberth, Kevin E. "Recent observed interdecadal climate changes in the Northern Hemisphere." Bulletin of the American Meteorological Society 71, no. 7 (1990): 988-993.

Trenberth, Kevin E., and James W. Hurrell. "Decadal atmosphere-ocean variations in the Pacific." Climate Dynamics 9, no. 6 (1994): 303-319.


Since we're tracking back history, this 1981 paper might be of interest - though it's probably peripheral to the subject, it was cited in Mantua, Hare et al (1997).

Trenberth, Kevin E., and Daniel A. Paolino Jr. "Characteristic patterns of variability of sea level pressure in the Northern Hemisphere." Monthly Weather Review 109, no. 6 (1981): 1169-1189.

What caught my eye was the opening sentence, particularly given Anthony's opening comments about Dr Trenberth "finally admitting to ... cyclic influences":

The atmospheric circulation is characterized by various "centers of action" which are spatially interdependent.

Since I've plugged the references here, I'll add the PDO paper:

Mantua, Nathan J., Steven R. Hare, Yuan Zhang, John M. Wallace, and Robert C. Francis. "A Pacific interdecadal climate oscillation with impacts on salmon production." Bulletin of the American Meteorological Society 78, no. 6 (1997): 1069-1079.


Back to the Nature article - here are some key excerpts discussing the "hiatus" in surface temperature rise in recent years:

Trenberth, ... estimated that aerosols and solar activity account for just 20% of the hiatus. That leaves the bulk of the hiatus to the oceans, which serve as giant sponges for heat. And here, the spotlight falls on the equatorial Pacific.

...Just before the hiatus took hold, that region had turned unusually warm during the El Niño of 1997–98, which fuelled extreme weather across the planet, from floods in Chile and California to droughts and wildfires in Mexico and Indonesia. But it ended just as quickly as it had begun, and by late 1998 cold waters — a mark of El Niño’s sister effect, La Niña — had returned to the eastern equatorial Pacific with a vengeance. More importantly, the entire eastern Pacific flipped into a cool state that has continued more or less to this day.

This variation in ocean temperature, known as the Pacific Decadal Oscillation (PDO), may be a crucial piece of the hiatus puzzle. The cycle reverses every 15–30 years, and in its positive phase, the oscillation favours El Niño, which tends to warm the atmosphere (see ‘The fickle ocean’). After a couple of decades of releasing heat from the eastern and central Pacific, the region cools and enters the negative phase of the PDO. This state tends towards La Niña, which brings cool waters up from the depths along the Equator and tends to cool the planet. Researchers identified the PDO pattern in 1997, but have only recently begun to understand how it fits in with broader ocean-circulation patterns and how it may help to explain the hiatus.

One important finding came in 2011, when a team of researchers at NCAR led by Gerald Meehl reported that inserting a PDO pattern into global climate models causes decade-scale breaks in global warming3. Ocean-temperature data from the recent hiatus reveal why: in a subsequent study, the NCAR researchers showed that more heat moved into the deep ocean after 1998, which helped to prevent the atmosphere from warming6. In a third paper, the group used computer models to document the flip side of the process: when the PDO switches to its positive phase, it heats up the surface ocean and atmosphere, helping to drive decades of rapid warming7.

A key breakthrough came last year from Shang-Ping Xie and Yu Kosaka at the Scripps Institution of Oceanography in La Jolla, California. The duo took a different tack, by programming a model with actual sea surface temperatures from recent decades in the eastern equatorial Pacific, and then seeing what happened to the rest of the globe8. Their model not only recreated the hiatus in global temperatures, but also reproduced some of the seasonal and regional climate trends that have marked the hiatus, including warming in many areas and cooler northern winters.

...That was investigated by Trenberth and John Fasullo, also at NCAR, who brought in winds and ocean data to explain how the pattern emerges4. Their study documents how tropical trade winds associated with La Niña conditions help to drive warm water westward and, ultimately, deep into the ocean, while promoting the upwelling of cool waters along the eastern equatorial region. In extreme cases, such as the La Niña of 1998, this may be able to push the ocean into a cool phase of the PDO. An analysis of historical data buttressed these conclusions, showing that the cool phase of the PDO coincided with a few decades of cooler temperatures after the Second World War (see ‘The Pacific’s global reach’), and that the warm phase lined up with the sharp spike seen in global temperatures between 1976 and 1998 (ref. 4).

The article goes on to discuss the work of Mark Cane, who proposes that global warming may lead to extended La Ninas.  Other scientists' work suggests that global warming may lead to more El Ninos. Time (and more research) will tell.

Now you'll be wondering why Anthony Watts mentioned the Atlantic Multidecadal Oscillation.  So am I.  It isn't mentioned in the Nature article although it is mentioned in Trenberth and Fasullo (2013).  Maybe Anthony actually read a scientific paper (not likely).

From the WUWT comments

There aren't any stand out comments, so I'll award the comment of the day to Anthony Watts himself for his opening comments about Kevin Trenberth, who was arguably very influential in shaping the understanding of what we know today as the Pacific Decadal Oscillation.

Most WUWT readers will be in for a big shock when the next El Nino arrives.


DirkH doesn't have a clue about climate models and says:

January 16, 2014 at 4:10 am
“The simplest explanation for both the hiatus and the discrepancy in the models is natural variability.”

No, that’s nonsense. The simplest explanation is that the theory is falsified, and that the models are wrong. In fact, EVERYTHING points at the models being wrong, false and useless. Not ONE thing points to the models being right, correct, or useful. There are simply no such reports. We should see thousands of triumphant papers confirming again and again that the models got this right and that right after many years of painstaking development, but we NEVER see any such report.

That’s like celebrating the 100,000th Lancaster bomber built and shipped over the Atlantic while not one of them ever made it through the Kammhuber line.

johnmarshall is a "scientists don't no nuffin'" denier and says:

January 16, 2014 at 4:12 am
Trenberth getting a reality hit?
One of his problems is a complete misunderstanding of latent heat which is where much heat has been used for in cooling at the surface and has stupid graphic in AR4 which uses a flat earth with 24/7 sunlight and no idea from where radiated energy comes from.

Chris Marlowe says:

January 16, 2014 at 4:29 am
The smartest of these guys will be looking for an exit strategy and will eventually look the other way if anyone suggests they were once on the bandwagon beating the drum.

Stephen Richards is a conspiracy nutter and says:

January 16, 2014 at 4:36 am
What I don’t want is for these guys to remain in place when this whole scam is exposed. Like Erlich they will just keep coming back with another scare for money scheme.

M Courtney struggles to understand climate and energy accumulation and says:

January 16, 2014 at 4:46 am
Not sure that this report does fully recognise the impact of natural cycles.
It seems to think that the cooling phase of the PDO exactly balances the warming from Greenhouse gases over several decades when the emissions have varied.

That raises two questions:
1 How come the balancing is so precise – are our emissions coupled to the PDO or is their effect swamped by the PDO?

2 If the PDO can match the magnitude of AGW on th ecool sided, can it match the magnitude of AGW on the warm side? If so, how do we know any of the 20thC warming was manmade?

Ivor Ward misunderstands what's written and thinks that Kevin Trenberth agrees with Bob Tisdale that there are leprechauns burning coal fires in the oceans and says:

January 16, 2014 at 5:02 am
So essentially he is saying that Bob Tisdale is right and he was wrong. Why does Trenberth not just say that and get it over with?

Jim Cripwell is about right (except when it comes to Australia's PM Tony Abbott) when he says (excerpt):

January 16, 2014 at 5:12 am
Unfortunately, what is written on WUWT carries little weight with our politicians and the MSM. 

graphicconception also mistakenly thinks that Kevin Trenberth attributes global warming to leprechauns like Bob Tisdale does, and says:

January 16, 2014 at 5:24 am
The temperature graph is a kind of integration of the PDO Index graph.
(You need to add 0.6 to the Index, cumulate and then scale. Where do I collect my Nobel Prize?)

So as Bob Tisdale has been saying, if I understand it correctly, PDO variations are not just oscillations about a mean. They leave a resultant change.

evanmjones knows nothing about science either.  I bet he thinks a fake sceptic invented the PDO when he says:

January 16, 2014 at 5:29 am
Yeah, they finally discovered the PDO. Sort of like a professional secretary discovering the Shift key. Bloody amateurs.
Now they need to “discover” that their panic was due to a positive PDO and, consequently, their “projections” were at least twice too high. Then maybe they can learn the rest of the alphabet . . .

I can't say I agree with clivebest when he says:

January 16, 2014 at 5:56 am
The graphic above shows that we have only just entered a new 30 year long cool period of the PDO. This means that there will be no further warming until ~2030. Warming may well then resume after 2030, but whichever way you look at it, climate sensitivity looks to be about one half of current IPCC estimates. How is the IPCC going to keep the egg off its face for the next 15 years ?

Source: NOAA

Conspiracy nutter Timothy spawned an idiot in David Ball, who says:

January 16, 2014 at 6:13 am
“Now, after having wasted at least 30 years of public money and time due to our false ideology, we return you to your regularly scheduled viewing,…..”
Idiots.

Resourceguy says:

January 16, 2014 at 6:26 am
At some point the deadenders will attack the wavering warmists and excommunicate them from the treasure hunt known as carbon tax revenue. The only question is whether it will be a peaceful process or a North Korean-style purge.

Clay Marley is mistaken if he thinks Bob Tisdale invented the "sloshing" ENSO.  Unlike Bob, who thinks the oceans will keep warming forever, Clay  is hopeful that Earth's temperatures will one day return to "normal".  He says "it has to end...":

January 16, 2014 at 6:38 am
First I’d heard the term “sloshing” is in Tisdale’s posts and book. It isn’t intended to be a scientifiky term. That Trentberth uses it probably means at least that he is reading Tisdale, which would be a good thing. But he is hoping/praying for another strong El Niño that would start the warming again.

Tisdale is saying that a strong El Niño will cause a rapid SST rise over much of the earth. After the event, SST’s cool slowly. If the El Niño events come frequently enough there isn’t enough time between them to cool completely. Thus we see a stairstep warming with slight cooling between events. This is what has been happening since around 1918.

It has to end though. We can’t keep getting strong El Niños until the oceans boil. So there must be some process that slows and weakens the El Niños and allows the rest-of-world to get back to lower temps.

Richard M says that Dr Trenberth "don't know nuffin'" about oceans and could learn a thing or two from Perennially Puzzled Bob.  This one is runner-up comment of the day - after Anthony's opening comment:

January 16, 2014 at 7:15 am
Trenberth doesn’t realize that El Niño events might not quite work the same during a -PDO. As Tisdale has demonstrated it is the after effects of the El Niño during a +PDO that have a lot to do with the step up warming that occurs even after the following La Niña. I have a feeling that the changes in circulation in a -PDO will eliminate that effect (didn’t see it during the 2009-2010 El Niño). That is probably why the global temperature falls during a -PDO.

I wonder how many copies of Tisdale’s books will find their way to NCAR? Or, should I say …. have found their way?

These WUWT-ers aren't just scientifically illiterate. They are deluded.  Here's another one from  Economic Geologist who says:

January 16, 2014 at 7:42 am
I think Trenberth is reading Tisdale, but will never give him credit. The AGW crowd will slowly morph their scientific positions as their predictions continue to fail, and no-one will be held accountable for all the money wasted on useless, misguided research. And no-one in the skeptic camp will be acknowledged for having seen the weaknesses in the climate community’s science. There’s no justice in this world.

Oh - that's more than enough. I can't be bothered reading the rest. You can read more here if you want to.