Learning About The AMO

Guest Post by Willis Eschenbach

I must admit to being greatly bemused by Michael Mann’s new (and sadly, paywalled) opus magnum about the Atlantic Multidecadal Oscillation (AMO), sometimes called Atlantic Multidecadal Variability (AMV). Here are a couple of quotes from our boy on the subject, emphasis mine:

Mann 2011:

“The AMO, defined as a 40-60 year timescale oscillation originating in coupled North Atlantic ocean-atmosphere processes, is almost certainly real

and

“This is a key finding of Knight et al (2005) (of which I was a co-author) as well as Delworth and Mann (2000) [the origin of the term ‘Atlantic Multidecadal Oscillation’ (AMO) which I coined in a 2000 interview about Delworth and Mann w/ Dick Kerr of Science].”

followed by Mann 2021

“Two decades ago, in an interview with science journalist Richard Kerr for the journal Science, I coined the term the “Atlantic Multidecadal Oscillation” (AMO) to describe an internal oscillation in the climate system resulting from interactions between North Atlantic ocean currents and wind patterns.  … Today, in a research article published in the same journal Science, my colleagues and I have provided what we consider to be the most definitive evidence yet that the AMO doesn’t actually exist.

I do enjoy Mann’s implication that he was the discoverer of the AMO phenomenon, when in fact it had been described in detail in 1994 by Schlesinger and Ramankutty, six years before the publication of Delworth and Mann. Also, in the linked Kerr article in Science that Mann refers to above, despite discussing the name “Atlantic Multidecadal Oscillation” in detail, Kerr never says that Mann named the phenomenon … but I digress.

First, what is the AMO? It is a slow temperature swing of the Atlantic, most visible in the North Atlantic. Here’s a graphic of the oscillation.

Figure 1. Long AMO, from NOAA. This shows a period of about 65 years. There are various instrumental versions of the AMO data. This is the longest instrumental version of the AMO held by NOAA, starting in 1856.

Since the first description of the AMO in 1994, the phenomenon has been extensively studied by any number of scientists. A search on Google Scholar shows 31,300 web pages discussing the AMO. So why does Michael Mann now claim it’s not a natural variation of the Atlantic?

Because “state-of-the-art” climate models say so … his study starts like this:

An analysis of state-of-the-art climate model simulations spanning the past millennium provides no evidence for an internally generated, multidecadal oscillatory Atlantic Multidecadal Oscillation (AMO) signal in the climate system and instead suggests the presence of a 50- to 70-year “AMO-like” signal driven by episodes of high-amplitude explosive volcanism with multidecadal pacing

(Protip—any time someone starts out by talking about “state-of-the-art climate models” you can safely ignore their claims … but again I digress.)

Mann’s claim in his new paper, Multidecadal climate oscillations during the past millennium driven by volcanic forcing (paywalled), is that in preindustrial times what people have been calling the “AMO” was actually a stable Atlantic that was being forced by sporadic volcanic eruptions that just happen to have the same frequency as the AMO. But then that volcanic forcing has died out in modern times, and just in the nick of time volcanic forcing has been replaced by anthropogenic forcing … funny how that works. In M. Mann’s world, it’s always the humans who are to blame.

In any case, I thought I’d see what I could learn from the data in both the instrumental and proxy AMO records, along with the volcanic records discussed by Mann. To start with, here’s the Amman et al. dataset that Mann et al. used of 61 tropical eruptions that they say drove the AMO before modern times. I’ve shown the eruptions as vertical lines. On top of these volcano lines, I’ve overlaid several of the empirical modes of a Complete Ensemble Empirical Mode Decomposition (CEEMD) analysis of the eruptions, showing the various longer-term cycles in the data.

Figure 2. Tropical volcanic eruptions, and various CEEMD modes.

Here’s the thing about signals. As the brilliant mathematician Joe Fourier showed way back a couple of centuries ago, any signal can be decomposed as the sum of underlying signals of various periods. CEEMD is like Fourier analysis, except it doesn’t break a signal down into regular sine waves. It breaks a signal down into underlying signals that can change over time, as you can see above.

Now, is there a cycle in the eruption data similar to the ~ 65 year period of the AMO? Well … kinda. But since each and every signal can be broken down into underlying signals, it may just be by chance. The underlying signals have to have some period, and it might just be fifty to sixty years, as in the volcanos.

So that’s the volcanos. How about the proxy records of the AMO? The main one that is discussed by Mann is the Wang et al study, “Internal and external forcing of multidecadal Atlantic climate variability over the past 1,200 years“. The data is available here. It’s based on “a network of annually resolved terrestrial proxy records from the circum-North Atlantic region.” In that study, Wang et al. distinguished between what they called “AMV”, Atlantic Multidecadal Variability”, and the AMO. They said that something like 30% of the variability of the AMV was from volcanoes, and when that’s taken out we’re left with the AMO. Me, I doubt that, because modern volcanoes show little effect on the AMO. I also wanted to see how well the eruptions matched up with their data, so I’ve used their raw “AMV” data.

First I looked at how well the Wang proxy records matched the instrumental records shown in Figure 1. I’ve also added in the 50-60 year empirical mode of the CEEMD analysis of the Amman eruption records shown above in Figure 2.

Figure 3. Two AMO records and one eruption record, 1856 to present.

We see a couple of things in Figure 3. First, the Wang paleo proxy AMV (red) is very close to the modern instrumental AMO (blue).

However, the Amman eruption data is a quite poor match to the modern AMO data. This is no surprise. Look at Figure 1. If you don’t know which year the huge Pinatubo eruption occurred, you couldn’t tell it from Figure 1.

Next, I looked at the longer term view of that same data. Figure 4 shows that result.

Figure 4. Two AMO records and one eruption record, 800 to present.

Again, some interesting things in Figure 4. First, the average length of the cycles in the Wang paleo AMV is 65 years, which matches the modern data.

However, as in the modern period, there’s a very poor fit between the Amman eruption data and Wang paleo data. Among other things, the period of the eruption data averages 55 years, not the 65 years of either the Wang paleo data or the modern instrumental data. So although at times it matches up with the Wang data, it goes into and out of sync with both the instrumental AMO and the Wang AMV data.

So … how did Mann et al. come to their conclusions? As mentioned above, computer models …

The CMIP5 Last Millennium multimodel experiments provide a pseudo-ensemble of N = 16 simulations driven with estimated natural forcing (volcanic and solar, with minor additional contributions from astronomical, greenhouse gases, and land-use change) over the preindustrial period (the interval 1000 to 1835 CE is common to all simulations). We estimate the forced-only component of temperature variation by averaging over the ensemble, based on the principle that independent noise realizations cancel in an ensemble mean.

(In passing, let me note that it is certainly not always true that averaging a number of model outputs means that the “noise realizations cancel”. But again I digress …)

I rather did like the idea of a “pseudo-ensemble”, however … is that a bunch of random computer models hanging out on a street corner smoking cigarettes and pretending to be an ensemble? But I digress …

And what were their conclusions (emphasis mine)?

The collective available evidence from instrumental and proxy observations and control and forced historical and Last Millennium climate model simulations points toward the existence of externally forced multidecadal oscillations that are a consequence of competing anthropogenic forcings during the historical era and the coincidental multidecadal pacing of explosive tropical volcanic activity in past centuries. There is no compelling evidence for a purely internal multidecadal AMO-like cycle.

His claim is that for about eleven centuries, “explosive tropical volcanic activity” made it look like there is an AMO. And coincidentally, just when the volcanic forces left off, a competition between CO2 and sulfate forcings caused the AMO swings.

You’ll forgive me if, given what I see in the Figures above, I don’t find that argument even slightly compelling.

Finally, this is what I love about studying the climate. The science is far from settled, and that gives me the opportunity to learn something new from every paper that comes out.

Here on our dry northern California coastal hillside, rain is forecast starting tomorrow morning and lasting two days. However, around here, rain forecasts even twelve hours out are sometimes way wrong, and it’s generally true for rain forecasts three or four days out. Funny thing about chaotic systems. They tend to be … well … chaotic.

[NOTE: It’s now “tomorrow morning” when the rain was supposed to start … bright sunlight and not a cloud in the sky. Gotta love chaotic systems.]

Seems like out here in the real world, the modelers don’t have that whole “noise realizations cancel” deal completely worked out … but I digress.

My best regards to all, skeptics and mainstream folks alike,

w.

PS—I sign everything I write with my initial, “w.”, and for the same reason I choose my words very carefully—because I wrote them, I take ownership of them, and I know that it is always possible I will be called upon to defend them. However, I can’t defend your interpretation of my words. So when you comment, please quote the exact words that you are discussing. This avoids endless misunderstandings.

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March 8, 2021 10:11 am

Willis,
Thank you for taking the trouble to do this analysis, so we don’t have to.

John Tillman
Reply to  Philip Mulholland
March 8, 2021 12:01 pm

Mann also tried to pin the Little Ice Age on volcanoes, as a regional phenomenon, rather than a global interval caused by repeated solar minima.

Caligula Jones
Reply to  John Tillman
March 8, 2021 1:33 pm

Way back in the days of UseNet, I ran into infamous serial Wiki censor William Connolly and he was as adamant that “everyone knows” that the LIA was local, short and not very impressive.

Its the scientific equivalent of denying Ruby shot Oswald…

John Tillman
Reply to  Caligula Jones
March 8, 2021 3:47 pm

A long-lived false meme sustained by the Carbonari.

Michael S. Kelly
Reply to  John Tillman
March 8, 2021 4:53 pm

Wait, Ruby shot Oswald? No way! It was some guy named Grasse Noel.

Taphonomic
Reply to  Michael S. Kelly
March 9, 2021 1:27 pm

I thought it was Neil deGrasse Tyson.

Sara
Reply to  John Tillman
March 8, 2021 6:04 pm

Well, in reality,Mann refused to acknowledge the existence of the LIA in the early days of his spiels, because it upset his line of blather. That was back when he first began to gain some notoriety.
But he also said that ice masses (similar to icebergs) and ice dams did not form on rivers, and this was right after a massive flow of ice masses had been caught on video flowing south down the Des Plaines River from its northern end. It was so spectacular that it was on the local news.
There is a reason his eyes are brown, you know.

Mohatdebos
Reply to  Sara
March 8, 2021 7:46 pm

Send him to St.Claire River in Michigan. Ice dams have been causing flooding recently. We could have used a Russian nuclear icebreaker.

David A
Reply to  John Tillman
March 8, 2021 8:11 pm

…and eliminated the MWP.

MarkW
Reply to  Philip Mulholland
March 8, 2021 12:02 pm

Nothing better than friends with time on their hands.

fred250
Reply to  Philip Mulholland
March 8, 2021 12:56 pm

AMO is clearly visible in Icelandic sea ice data even through the LIA.

comment image

Duker
Reply to  fred250
March 8, 2021 11:44 pm

Iceland…..don’t they have volcanoes too and are slap bang in the middle of the north Atlantic. No there’s a forcing that should leap out the data?

Neo
March 8, 2021 10:12 am

There was a urban legend around UNIVAC that one guy got a patent for a electronic circuit .. followed by second guy who got a patent on the same circuit with a resistor value changed .. followed by third guy who got a patent on the same circuit with the resistor value changed back.

I’m seeing Mann as the second guy.

Bryan A
Reply to  Neo
March 8, 2021 12:09 pm

Resistance is Futile

Pat from kerbob
Reply to  Bryan A
March 8, 2021 1:02 pm

“Resistance is …. not futile”? 3rd of 5

11C47EC4-A74C-4290-B4E2-EBE610E462DB.jpeg
Reply to  Pat from kerbob
March 8, 2021 1:19 pm

Love it – thanks

Pat from Kerbob
Reply to  Roger Caiazza
March 8, 2021 1:47 pm

3rd of 5, AKA “Hugh”.

Last edited 4 months ago by Pat from Kerbob
Sara
Reply to  Pat from kerbob
March 8, 2021 6:06 pm

Priceless!

ATheoK
Reply to  Neo
March 8, 2021 3:40 pm

I think the 2nd and 3rd guy are manniacal.
Then manniacal claims he invented the name ‘circuit’.

Rag
Reply to  ATheoK
March 9, 2021 5:32 am

And although he got a patent on a circuit board, the manniacal says electricity does not exist

ResourceGuy
March 8, 2021 10:17 am

Well, someone in the agenda science ranks had to step forward to erase or confuse the AMO cycle. It might as well be the ring leader.

I guess this means the AMO is now seen as the most challenging issue for the Climate Crusades. It must be stopped at all costs. That also means they see it for what it is but don’t want to acknowledge it publicly. Send out the goon squad instead.

Congrats to those who already saw the AMO as a major cyclical cooling force coming into the forefront from this simple concept of cycle turning points. All we need now is some honesty surrounding the problems of detrending it or allowing for cycle differences on peak amplitude.

Better hurry though because Uncle Joe is about to wreck the economy based on not knowing anything about the AMO or its implications. No pressure–just facts

Ian W
Reply to  ResourceGuy
March 8, 2021 10:40 am

Uncle Joe will have joined the Paris Accord and dropped a whole shedload of dollars into the Green Fund for China (who will NOT thank him).
The AMO will fall and it will get significantly colder – Joe and John Kerry will declare victory over AGW. It will continue to get colder. The obvious way for Joe to stop the freeze is to get a rebate from the Green Fund…….
That is as logical as Mann checking models against the real world and declaring the real world as wrong.

Taphonomic
Reply to  Ian W
March 9, 2021 1:33 pm

If it gets significantly colder, it will be difficult to claim victory, as there is no way that atmospheric CO2 will stop increasing thanks to emissions from China, India and Third World Countries.

Reply to  ResourceGuy
March 8, 2021 10:55 am

As AMO is cyclic, and following a warm period is a cool period, have we to be aware of coming volcanoe erutions ?
Else, I see no “external forcing” for the coming cooling AMO period.

Last edited 4 months ago by Krishna Gans
Thomas Mee
Reply to  Krishna Gans
March 8, 2021 7:27 pm

They will drop nuclear bombs in volcanos, so they have something to blame.

MarkW
Reply to  ResourceGuy
March 8, 2021 12:07 pm

Krugman has apparently convinced Uncle Joe that the reason why Obama’s $800million infrastructure bill didn’t stimulate the economy was because it was too small.
To fix that problem, they are currently discussing a $3Trillion dollar infrastructure bill. No doubt, like the COVID relief bill, most of the money will be directed towards blue states. But there is no politics here.

Retired_Engineer_Jim
Reply to  MarkW
March 8, 2021 2:59 pm

OK, I live in a blue state (possibly the bluest) and our Governor, by a mere signature, redirected a new tax to fix the roads to another cause. We will look fore=ward to all that infrastructure money flowing out of Our Nation’s Capitol. However, I won’t hold my breath waiting for the roads to get fixed.

David A
Reply to  Retired_Engineer_Jim
March 8, 2021 8:16 pm

…and California can expect little of the magical maniac money to go towards water infrastructure.

drh
Reply to  David A
March 9, 2021 6:40 am

It’ll likely to fund the high speed rail. It doesn’t go anywhere but, hey, at least it’s an expensive boondoggle.

Drake
Reply to  ResourceGuy
March 8, 2021 5:13 pm

I am sorry, but according to The Princess Bride, they are the BRUTE squad.

Max:
Beat it or I’ll call the Brute Squad!
Fezzik:
I’m on the Brute Squad.
Max:
[sees Fezzik’s size] You are the Brute Squad!

Terminology is so important

eck
Reply to  ResourceGuy
March 8, 2021 6:53 pm

“Uncle Joe” doesn’t know anything about anything. He’s a stooge. Check for the “radical handlers” behing the curtain.

Duker
Reply to  eck
March 8, 2021 10:56 pm

The most experienced president since the 1960s…
The stooge was the guy who spent his time on the golf course and watching daytime TV

alacran
Reply to  Duker
March 9, 2021 8:33 am

Oh yes,sure, what am I doing here, eh, I’ll have to look at my memory card, uh, eh, experience is a weird thing……

Duker
Reply to  alacran
March 9, 2021 10:51 am

Read a transcript of the other guys speeches, mostly incoherent rambling
Remember the Oval Office speech that cut of americans from returning home…had to be corrected, or the internal blue lights thing , or the tweets that were deleted because they were nonsense

MarkW
Reply to  Duker
March 9, 2021 7:23 pm

Can you repeat that, this time in English?
Or has hatred caused you to have a stroke?

MarkW
Reply to  Duker
March 9, 2021 7:22 pm

Being the oldest doesn’t make him the most experienced.
So what if he takes in an occasional round of golf?

Your partisan hatred has rotted your brain. You aren’t even trying to make sense any more.

Burl Henry
Reply to  eck
March 9, 2021 11:33 am

eck;

What is even worse, the “Joe Biden” that we now see is an imposter. No idea who he is. Compare images of him before 2019, and the present, especially note the different right ear lobe. There are other subtle differences. Sean Hannity ran a piece on this. .,

damp
Reply to  Burl Henry
March 9, 2021 5:44 pm

This “Joe Biden” is the real Paul McCartney.

Burl Henry
Reply to  damp
March 9, 2021 6:49 pm

damp.

No, Paul’s right earlobe is not attached to his cheek, as is the fake Joe’s

March 8, 2021 10:18 am

Manns paper passed peer-review ?
unbelievable….comment image

Michael 63
Reply to  Krishna Gans
March 8, 2021 10:29 am

Believe it, his peers reviewed it – he’ll probably review something of theirs soon. /s

RelPerm
Reply to  Michael 63
March 8, 2021 4:10 pm

Same comment but no /s

Jean Parisot
Reply to  Krishna Gans
March 8, 2021 10:34 am

Science (the Journal) is getting worse than the PNAS

AGW is Not Science
Reply to  Jean Parisot
March 8, 2021 8:08 pm

It’s more like Pravda at this stage.

Bryan A
Reply to  Krishna Gans
March 8, 2021 12:13 pm

It’s Loo Paper and Pee-er review

Thomas Mee
Reply to  Bryan A
March 8, 2021 7:29 pm

Lew paper.

ResourceGuy
Reply to  Krishna Gans
March 8, 2021 1:06 pm

It’s good enough for political peer review.

Caligula Jones
Reply to  Krishna Gans
March 8, 2021 1:35 pm

Hey, if they can accept, peer review and publish a paper in TWO DAYS stating that PCR tests are acceptable for COVID19, then, yeah, its believable.

Its 2021 and the word “science” has been post-moderned out of existance…

James
Reply to  Krishna Gans
March 8, 2021 3:39 pm

Unbelievable!! How it passed the peer review! We need the name of the Editor and all reviewers! It is high time to demand disclosing the peer review report. Put all the scientific comments as raised by many scientists and experts in the form of open peer-review. This published paper is so absurd and has no merit.

Can science go like that? Sensible scientists need to step up!

Gerald Machnee
Reply to  James
March 8, 2021 6:16 pm

Pal-review.

eck
Reply to  Krishna Gans
March 8, 2021 6:55 pm

No. It was a Pierce review. Seymore Peirce. Don’t know him??

John in Oz
Reply to  Krishna Gans
March 8, 2021 8:24 pm

Willis has just peer reviewed it and proved it wrong.

Real peer review only occurs when a paper becomes public and, as Einstein said, ‘It only takes one to prove me wrong’.

Burl Henry
Reply to  John in Oz
March 9, 2021 11:47 am

John in Oz:

“It only takes one to prove me wrong”

Good point.

I offer my paper “A Graphical Explanation of Climate Change”

http://www.skepticmedpublishers.com/article-in-press-journal-of-earth-science-and-climatic-change/

Any takers?

Ron Long
March 8, 2021 10:32 am

Interesting posting, W. As a geologist with a lot of experience with volcanic activity (OK, especially volcanic activity that produces gold deposits) I cannot imagine what cyclic, or oscillation if you prefer, could possibly control the timing of volcanic eruptions. Let’s e clear here, at least half of volcanic eruptions are on the sea floor, and not many detected. Then you face the issue of how explosive does a volcanic eruption have to be to get aerosols into the atmosphere where they MIGHT modify the weather/climate. The big, explosive, volcanic eruptions are all subduction related, where the melt incorporates crustal material as it ascends to a magma chamber (ascends based on density contrast) then the composite melt sits there and undergoes progressive crystal fractionation, resulting in accumulating volatiles, then the bad tacos event occurs and the magma chamber is emptied in explosive fashion. How can there be a cyclicity to this complex sequence of steps?

Kevin kilty
Reply to  Ron Long
March 8, 2021 10:46 am

I think one can look at the sporadic nature of eruptions, each of which likely has some different impact on climate (more or fewer stratospheric aerosols produced), and see a cyclic pattern if one is needed.

John Tillman
Reply to  Ron Long
March 8, 2021 10:49 am

A 2012 study of Pacific sediments did find a correlation with the 41k year Milankovitch obliquity cycle:
https://pubs.geoscienceworld.org/gsa/geology/article-abstract/41/2/227/131209/A-detection-of-Milankovitch-frequencies-in-global?redirectedFrom=fulltext

But that’s a far cry from a multidecadal oceanic oscillation.

Reply to  Ron Long
March 8, 2021 11:13 am

“How can there be a cyclicity to this complex sequence of steps?”
Oh, man, where to start… I’ll leave it to better mathemathingy guys. Complexity is the stuff Nature builds the most beautiful cycles upon. Just go look at a cloud…
Does anyone have data on geostorms before and since fracking become a “revolution”? I have serious doubts about that programme.
I define “geostorm” as tectonic events, underground thunder if you like. And geostresses directly influence local weather (Devereaux) and animal behaviour. You know, all the fish run to high ground and the elephants climb trees before the tsunami hits?
More of that sort of thing since fracking came to this part of the world. Volcanoes release a lot of geostress quickly, which can change weather patterns, even enough to start a butterfly effect?
Sorry to ramble, had this on my mind again for some months now. I would not be surprised, should someone show AMO and volcanic activity to be part of the same underlying frequency. What is the life expectancy of your average continent floating on a pool of lava millions of years in the burping?

Thomas Mee
Reply to  Willis Eschenbach
March 8, 2021 7:33 pm

Isn’t the volcanic cycle just an artifact of the data? Things that are not cyclic can have cycles …. random chance.

Reply to  Willis Eschenbach
March 8, 2021 8:34 pm

Tectonic events: Stresses building up in the crust. Stresses releasing in the crust. Volcanoes, earthquakes and tremours. Subsidence and extrusions(?) and plates crushing against each other, you know, “underground weather”? Imagine the mantle to be just another type of atmosphere, Like fish swim and birds fly, earthworms ooze through this medium, solid to us, but then, humans have a rather narrow bandwidth of existence. Do I measure it? As much as I do lightning strikes, which, in my personal life, consists mostly of “hey, dude, that was close by, let’s get off the roof”.
Then I wave my hands at the damage done afterwards, helpless against forces anything bigger than my umbrella can handle. While I invent definitions for terms I use to convey an idea I spend much time pondering, because none of the clever guys bother writing anything on the subject I understand. And from the many downvotes, it seems I failed miserably at stating my question, which remains: how has the underground weather changed since fracking became a financial miracle? From my personal, biased perspective, it seems things have become rather stormy.
I guess someone will try convince me it’s the ‘cancer factor’, where we excuse the horrendous upsurge in cancer caused by the poisoned food chain, to the marvelous advances in medical technology; “we find more because we test more”. We hear of more tremours, quakes and outbursts, because our instruments are better? Maybe, I doubt it.

bigoilbob
Reply to  paranoid goy
March 9, 2021 5:59 am

Fraccing has nada to do with this discussion. It’s earthquake swarms are real and measures to minimize/avoid them should be mandated. I,e, more, better, and better spotted hazardous waste disposal wells.

MarkW
Reply to  bigoilbob
March 9, 2021 7:28 pm

Yea, we gotta avoid those super damaging 1.0 earthquakes.
There is no evidence that there is anything wrong with the current disposal methods.

bigoilbob
Reply to  MarkW
March 10, 2021 5:29 am

“Yea, we gotta avoid those super damaging 1.0 earthquakes.”

Not bad for you. Only off by few logarithms (Richter scale look it up).

https://en.wikipedia.org/wiki/Oklahoma_earthquake_swarms_(2009%E2%80%93present)

School time. Oklahoma and Texas haz waste disposal wells were mostly constructed 50+ years ago, and their standards are awful. Poorly tubed, poorly cemented. And they were meant to dispose of fluids at rates orders of magnitude lower than required by modern shale* development. Additionally, at least in Oklahoma, the Arbuckle shale is increasingly resistant to haz waste injection (injection pressures are increasing). This increased stress, along with the concomitant lubricity from the fluids, causes the damaging quakes.

Just one more external cost of shale development, passed along to the public…

*The linked article is mistaken about the incremental volumes coming from the Mississippi and the Hunton. Most of those produced fluids are reinjected into those intervals,

Last edited 4 months ago by bigoilbob
Reply to  Ron Long
March 8, 2021 11:42 am

On the issue of how explosive, I studied that and wrote up the results as part of essay Blowing Smoke in the eponymous ebook while debunking a really bad Colorado University paper.
The answer is almost no VEI 4, but most VEI 5 and 6, throw aerosols into the stratosphere where they only slowly wash out so can (for a couple of years) effect surface temperatures by changing albedo (measured as stratospheric opacity, or the equivalent optical depth). Up through VEI 4, the troposphere volcanic washout is typically at most a few weeks. It depends on the latitude of the volcano and the season. Higher latitudes have a higher troposphere aerosol residence time.

Burl Henry
Reply to  Rud Istvan
March 8, 2021 1:07 pm

Rud Istvan:

I, too, have studied the effect of volcanic eruptions, and I have found that VEI4 eruptions typically cool the :atmosphere for a year or more, and usually result in the formation of a La Nina. Few, if any, VEI3 eruptions have any climatic effect.

See “A Graphical Explanation of Climate Change”

http://www.skepticmedpublishers.com/article-in-press-journal-of-earth-science-and-climatic-change/

And: “The Definitive Cause of Little Ice Age Temperatures”

https://www.osf.io/bmu69/

Both show that most VEI4 eruptions result in decreases in average anomalous Global temperatures.

Robert W Turner
Reply to  Ron Long
March 8, 2021 12:37 pm

Bad tacos event? Oof, that’s why I hold the hot sauce when there is risk of bad taco subduction.

Anon
Reply to  Ron Long
March 8, 2021 2:33 pm

Hi Ron,

You might want to check this lecture out from Willie Soon:

The “Global Blue Sun”: Solar Anomaly during 1450s-1460s?
https://youtu.be/XxiQoanjvLE?t=2379

He is discussing a different topic, but gets into about 20 mins of Solar Perturbation Theory relating that to the historical minimums and warm periods (where I started the video). Then at 44:18 he starts discussing volcanic eruption patterns. This is not relevant to the period Mann is postulating, but since you stated: “I cannot imagine what cyclic, or oscillation if you prefer, could possibly control the timing of volcanic eruptions”, I thought you might be interested. As I am a chemist, I can’t evaluate any of it, but found it fascinating. FYI.

Last edited 4 months ago by Anon
menace
Reply to  Ron Long
March 8, 2021 10:03 pm

then the bad tacos event occurs and the magma chamber is emptied in explosive fashion

I’ve had some emptying in explosive fashion from some bad tacos, not pleasant at all

Sara
Reply to  Ron Long
March 9, 2021 6:02 pm

Ron Long, when Pinatubo erupted, the debris was a high enough volume to block sunlight and drop the global mean temperature by (I think) ONE degree Fahrenheit. It was brief, but it did happen. That was some time ago, but the records should be somewhere.

Editor
March 8, 2021 10:33 am

Let’s suppose that there really is a volcanic cycle in sync with the AMO. Isn’t it possible that the volcanic cycle could be caused by the AMO, not the other way round? The AMO would change the pressure patterns on Earth’s crust, and that could affect volcanic activity.

Did Michael Mann look at the PDO too? Or is that going to have to be eliminated next?

Notanacademic
Reply to  Mike Jonas
March 8, 2021 12:51 pm

Mann attempted to get rid of the mwp and the lia with his hockey stick, recently they tried to get rid of the Holocene optimum and now the amo so yes your probably right and the pdo will be next. Wonder what will be deleted after that?

Clyde Spencer
Reply to  Mike Jonas
March 8, 2021 1:08 pm

Mann’s First Law: Never consider hypotheses that do not agree with what you are trying to sell.

AGW is Not Science
Reply to  Mike Jonas
March 8, 2021 8:13 pm

Well, getting cause and effect backwards is “climate science” stock-in-trade, after all.

Robert W Turner
March 8, 2021 10:41 am

Ah yes the ol’ “state-of-the-art” models. Just like Pablo Picasso painted state-of-the-science pieces.

AGW is Not Science
Reply to  Robert W Turner
March 8, 2021 8:15 pm

In the definitions of “sciency” terms, “state of the art” means “the latest absolute crap.”

Notanacademic
Reply to  Robert W Turner
March 9, 2021 6:20 am

The art must be in a terrible state me thinks.

Kevin kilty
March 8, 2021 10:41 am

In just today’s TWTW we find…

Climate network detects precursor of Pacific Decadal Oscillation phase transition

By Li Yuan, Chinese Academy of Sciences, Mar 1, 2021 [H/t Bernie Kepshire]

https://phys.org/news/2021-03-climate-network-precursor-pacific-decadal.html

Link to paper: Early warning of the Pacific Decadal Oscillation phase transition using complex network analysis

By Zhenghui Lu Naiming Yuan Qing Yang Zhuguo Ma Jürgen Kurths, Geophysical Research Letters, Feb 11, 2021

https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020GL091674

It is so unfair that the Pacific has its decadal oscillation, but Mann took away the Atlantic’s. So unfair.

Bryan A
Reply to  Kevin kilty
March 8, 2021 12:18 pm

Perhaps the Atlantic should Tsu

Reply to  Kevin kilty
March 8, 2021 2:18 pm

Early wanrnig about 6.5 years in advance of a phase shift shouldt be better and more accurate than the Schellnhuber / PIK El Niño warning a year in advance that in reality became a La Niña ;-/

Editor
March 8, 2021 10:47 am

This is a classic case of deciding the answer, and then finding a way to “prove” it.

commieBob
Reply to  Paul Homewood
March 8, 2021 11:44 am

I was going to say that’s what lawyers do. I realize that comparing Dr. Mann to a lawyer is a serious affront to lawyers everywhere and I am deeply sorry for even thinking such a thing.

Lawyers are officers of the court and they have legal and ethical obligations. For instance, a lawyer may not hide evidence or concoct evidence or present misleading evidence. (That said, a lawyer may have conflicting duties and things can get complicated.) I don’t know any lawyers who aren’t scrupulously honest.

Anyway, it always brings me joy to point out that, because of his conduct in the Ball case, Mann has confessed to being a fraud by way of adverse inference. He has thus admitted that he belongs in the state pen because, if he had evidence otherwise, he should have produced it.

Clyde Spencer
Reply to  commieBob
March 8, 2021 1:11 pm

I don’t know any lawyers who aren’t scrupulously honest.

Don’t both of the Clinton’s have law degrees?

John Tillman
Reply to  Clyde Spencer
March 8, 2021 3:11 pm

Bill’s was revoked, with good cause.

Then there’s Rod Blagojevich and the Obamas, sterling stars of the legal profession in IL.

Last edited 4 months ago by John Tillman
commieBob
Reply to  Clyde Spencer
March 8, 2021 3:35 pm

My bad.

I don’t personally know any lawyers who aren’t scrupulously honest.

Clyde Spencer
Reply to  commieBob
March 9, 2021 9:30 am

And I too would disavow personally knowing any lawyers who were dishonest. 🙂

Michael Jankowski
Reply to  commieBob
March 8, 2021 3:41 pm

Scrupulously honest? Politics is overloaded with lying lawyers.

Vuk
Reply to  Paul Homewood
March 8, 2021 1:14 pm

Find or not an answer it still could be part of a useful scientific research. Both Maxwell and Einstein looked for answers to their ‘thought experiments’ and concluded they did found adequate answers, but neither could prove it. Proofs came some years later provided by Heinrich Hertz and the space technology.

Caligula Jones
Reply to  Paul Homewood
March 8, 2021 1:37 pm

Yes, the opposite of what the left typically does, i.e., sees something work in practice but dismiss it because it doesn’t fit the theory.

AGW is Not Science
Reply to  Paul Homewood
March 8, 2021 8:17 pm

As is the entire notion of “anthropogenic” global warming/climate change/whatever-they-call-it-next-week.

Robert W Turner
March 8, 2021 10:47 am

There is no compelling evidence for a purely internal multidecadal AMO-like cycle.”

Ah there it is, a non-linear dynamic cycle is not linear and therefore there is no natural cycle. Akin to an area during the LIA that was warmer than today and an area during the MWP that was cooler than today so therefore they do not exist.

There seems to be a lot of hubris from the climate cult about the AMO being completely controlled by man lately, almost like they are expecting global cooling to kick in.

Last edited 4 months ago by Robert W Turner
Reply to  Robert W Turner
March 8, 2021 11:03 am

AMO hasn’t to exist as real scientists found out, climate is driven by ocean cycles

Bryan A
Reply to  Krishna Gans
March 8, 2021 12:21 pm

Climate is driven by the Whims of Mann and Model Drivel

JCM
March 8, 2021 10:50 am

It is only climate scientists who use language of “internal” and “external” forcing. Earth system scientists understand that everything is related ecologically. Furthermore, the self contained biosphere is a myth – the Earth system is not separate from the solar system. Similarly, what we call “climate” is not separate from geology. We perceive them and label them as separate systems, but in fact they are coupled. You cannot separate one from another, and in doing so leads to false assumptions and invalid conclusions.

Last edited 4 months ago by JCM
AGW is Not Science
Reply to  JCM
March 8, 2021 8:20 pm

To take things a step further, obsession with “forcings” while ignoring “feedbacks” makes the entire exercise little more than mental masturbation.

Vuk
March 8, 2021 10:59 am

About 10 or so years ago I compared the N.Atlantic SST ( de-trended data is known as the AMO) to the N. Atlantic tectonic activity, both visual inspection and correlation of just under 0.7 would suggest causal relationship. I suspect it might be related to effect on down-welling in the Icelandic region of the Atlantic.

NAP-SST.gif
Reply to  Vuk
March 8, 2021 11:09 am

NAO
data

Last edited 4 months ago by Krishna Gans
Vuk
Reply to  Krishna Gans
March 8, 2021 11:50 am

AMO-NAO oscillate in anti-phase, akin to an LC electric circuit
(p.s. all my graphs are out of date some more than others)

NAO-AMO-oscillator.gif
Vuk
Reply to  Vuk
March 8, 2021 11:12 am

However, there is some co-incidental similarity in the longer term of the N. Atlantic tectonics and solar activity

SSN-NATR.gif
Vuk
Reply to  Willis Eschenbach
March 8, 2021 1:16 pm

See my comment to John Tillman below.

John Tillman
Reply to  Vuk
March 8, 2021 11:13 am

So if it were volcanoes before the rise in man-made CO2, it still is volcanoes.

Vuk
Reply to  John Tillman
March 8, 2021 12:59 pm

Hi John
At the moment I’m inclined to think it is more to to do with ocean currents than the CO2.
I’m a bit puzzled by the tectonics – sunspot coincidence, unlikely to be be related to the orbital mechanics, possibly geomagnetic lithospheric induction.
There is strong evidence of electromagnetic processes responsible for earthquake (& volcanoes? -vuk) triggering, that we study extensively. We will focus here on one correlation between power in solar wind compressional fluctuations and power in magnetospheric pulsations and ground H component fluctuations.”
Geophysical Research Abstracts,Vol.8,01705, 2006;Lab for Solar and Space Physics, NASA Goddard Space Flight Center,Greenbelt, MD
http://www.cosis.net/abstracts/EGU06/01705/EGU06-J-01705.pdf
https://earth-planets-space.springeropen.com/articles/10.1186/s40623-015-0213-3)

John Tillman
Reply to  Vuk
March 8, 2021 3:00 pm

Does “tectonics” include earthquakes as well as volcaniic eruptions?

Rory Forbes
Reply to  John Tillman
March 8, 2021 4:33 pm

Does “tectonics” include earthquakes as well as volcaniic eruptions?

Most definitely it does. It’s all part of the same dynamic.

Bill Rocks
Reply to  John Tillman
March 9, 2021 9:30 am

As I recall, tectonics is defined as “forces and movements within the earth’s crust”, circa 1971.

Vuk
Reply to  Vuk
March 8, 2021 11:18 am

Long term CET data is also co-related to the N. Atlantic tectonics, hence dismissing above relationships as ‘pure coincidence’ it might be premature.

CET-NATR.gif
Vuk
Reply to  Willis Eschenbach
March 8, 2021 12:04 pm

Of course England’s temperature is related to N. Atlantic SST, the weather forecasters over-here tell us that daily often more than once. I put that graph there to show longer term (350+years) co-incidence since the AMO data goes back only about 150 yrs.
Whether it has or has not anything to do anything with tectonics (indirectly via N.Atlantic SST) it is a matter of conjecture. My graph makes me think it is more likely than not (of course I’m biased, since I have studied the CET for at least a decade, it affects me on the daily basis). On the other hand anyone is free to take opposite view according to their interpretation of available data and the relevant science .

Reply to  Vuk
March 8, 2021 2:31 pm

I think it’s more interesting to look for quantifying tectonics with CO2 outgassing. There are several papers about. 😀

Nelson
Reply to  Vuk
March 8, 2021 2:33 pm

Vuk and Willis

I wonder what role, if any, galactic cosmic rays have on volcanic activity. Low solar activity mean relativity weak solar winds, which help protect the earth from GCRs. GCRs penetrate deep into the earth and I won’t be surprised if the data shows they help set off volcanic activity. I have seen references that point to major volcanic activity being correlated with low sunspot activity. More to the point, I continue to be surprised that more is not being made of the weakening of the earth’s magnetic field, which also helps protect against GCRs. While the earths magnetic field started dropping in the mid 1800s, it has really picked by speed the last few decades. The field is dropping at 5% per decade currently and the drop seems to be accelerating. If this continues, I think the earth could be in for some interesting times. “Ship of Fools” Turney just published a piece about the magnetic excursion 42k years ago, which was not a pleasant time. It seems like the earth experiences magnetic excursions about every 12k years and we are about due if the cycle does exist. If we lose another 5% of the field in the next 10 years and the 25th cycle is as weak as the 24th and the AMO rolls into the negative phase, I think the worry about CO2 will quickly fade.

Vuk
Reply to  Willis Eschenbach
March 8, 2021 12:21 pm

Lots of questions there to answer in one go.
In brief, data is collected and cross-referenced from a number of institutions (Smithsonian, BGS, Iceland Geosurvey, BGR, BRGM, etc ) all  publicly available. Output calculated according to formula on the graph. If ever complete the paper started some years ago I will have much more to say, and if the WUWT is still around I certainly will make an announcement.
 

Vuk
Reply to  Willis Eschenbach
March 8, 2021 1:42 pm
Reply to  Vuk
March 8, 2021 2:36 pm

The 11 year running mean shows an encrease

Clyde Spencer
Reply to  Vuk
March 8, 2021 1:20 pm

Looking at your graph, you don’t have a correlation of 0.7. That is your r^2 value. Your r value is about 0.83.

Vuk
Reply to  Clyde Spencer
March 8, 2021 2:18 pm

Yes, thanks Clyde.

Richard M
March 8, 2021 11:01 am

The climate changes for the Holocene could be explained by natural salinity changes over time along with natural ocean cycles such as the AMO. The salinity cycle was created by melt pulses at the end of the last ice age. Lots of cold fresh water entered the Arctic and North Atlantic undercutting warmer ocean water.

The Younger Dryas could have been a period when the cool, fresher water returned to the surface.

It is possible the next higher salinity cycle led to the Holocene Optimum with the additional feature where the global MOC slowed. This extended the warm period. However, the current has since gotten back up to speed and we see millennial periods of warming and cooling as the water traverses the globe.

The MWP was the last period of higher salinity. The LIA was created by a drop in salinity. We have been in a time of rising salinity for the past ~500 years.

https://www.nature.com/articles/s41467-018-02846-4/figures/2

Over the past century humans have been adding to the salinity of the oceans via salt usage for water treatment, deicing, farming, etc.

The AMO could also be salinity driven as well, driven by cyclic melting of polar ice to freshen portions of the AMOC.

It all fits together nicely. Now is it true? There’s no money in studying this kind of natural phenomena so chances are it will be ignored for many years to come.

Wim Röst
Reply to  Richard M
March 8, 2021 12:11 pm

Good point: the role of salinity is usually overlooked. Most deep downwelling is where salinity (in colder seas) is highest: in the northern Atlantic. The warm Gulfstream transports the most saline surface waters from the North Atlantic Gyre (around 30°N) to the higher latitudes of the Atlantic, enabling ‘warmer than normal’ water to sink and/or to enter the Arctic Ocean area as ‘warmer than normal’ subsurface water. It is THIS warmer water that caused the recent decades of ice melt in the Arctic which changed weather patterns etc. etc. That warmer than normal water is progressing along the Siberian coast to the east. More open water in the arctic north of East Siberia (during summertime and autumn) is changing regionally the quantity of water vapor in the air and in this way is changing pressure patterns.

When air pressure patterns change, winds change and by consequence ocean currents will change. And then salinity changes. It will be interesting years to come.

Clyde Spencer
Reply to  Wim Röst
March 8, 2021 1:23 pm

Most deep downwelling is where salinity (in colder seas) is highest: in the northern Atlantic.

I thought that surface salinity was highest in the tropics, where there is a lot of evaporation taking place.

Wim Röst
Reply to  Clyde Spencer
March 8, 2021 2:10 pm

Clyde Spencer: “I thought that surface salinity was highest in the tropics, where there is a lot of evaporation taking place.”

WR: It is the highest in the tropical gyres and more especially in the North Atlantic Tropical Gyre. That’s why I wrote: “where salinity (in colder seas) is highest”.
It is this very saline surface water of the most saline gyre (the North Atlantic Gyre) that is brought to the highest latitudes by the Warm Gulf Stream and (mixed with precipitation and fresher water from ice melt) still has the highest salinity of the cold oceans, resp. the oceans at the highest latitudes. Perfectly shown by Willis’ map below. Compare the North Atlantic with the North Pacific at the same latitude. The Southern Ocean (near Antarctica) is fresher as well.

Last edited 4 months ago by Wim Röst
MarkW
Reply to  Clyde Spencer
March 8, 2021 4:13 pm

There’s a lot of evaporation, but there is also a lot of rainfall

DonM
March 8, 2021 11:14 am

It’s almost like somebody besides Mann labeled photo in the way they did.

The “fingerprint of AGW” points to Mann’s fingers in the photo;

Mann’s fingerprint is all over the exaggeration of tree rings (tea leaves, knuckle bones, and chicken guts) with respect to Mann’s anthropocentric climate claims.

Bryan A
Reply to  Willis Eschenbach
March 8, 2021 12:28 pm

And BRILLIANT

March 8, 2021 11:16 am

Digressing in a chaotic system is not really digressing.

Jeff Alberts
Reply to  leonardo
March 8, 2021 12:12 pm

Willis likes to digress. But I think he likes telling us he’s digressing more than the actual digression.

Joel O'Bryan
March 8, 2021 11:20 am

Judith Curry made it pretty clear what Mann’s motivation is to eliminate the AMO as a phenomenon.

“Wow. In one fell swoop, the pesky problems of the ‘grand hiatus’ in the mid 20th century, debates over the attribution of 20th century warming and the role of multidecadal internal variability, and the difficulty of attributing the recent increase in Atlantic hurricane activity to AGW, all go away. Brilliant! Almost as ‘brilliant’ as the Hockey Stick.”

Mann has been alarmist’s go-to carnival barker after every hurricane to claim they’ve been made more intense due to CO2 driven AGW. The AMO explanation blows up his fraudulent claims on recent hurricane intensity, so now he goes after the AMO.
Now when goes on some interview and claims this or that hurricane has been made more intense due to AGW, if someone tells him the AMO shift explains it, he can tell them peer-reviewed literature” shows the AMO to be figment of past volcanic forcings.

It’s all very much Orwellian-motives to send inconvenient observations down the memory hole and further the climate scam. But I can assure you somewhere in Mann’s latest attempt to weave a tangled-web of a new narrative on the Atlantic AMO and hurricanes something else comes unraveled in the climate scam as he attempts to deceive.

Last edited 4 months ago by joelobryan
John Tillman
Reply to  Joel O'Bryan
March 8, 2021 12:40 pm

The list of natural cycles which must be done away with keeps growing. First, the Team had to get rid of the Medieval WP, pounding it into submissin by high sticking, then the LIA and now oceanic oscillations, with possible exception of ENSO, as too well established. The Roman, Minoan and Egyptian WPs and the Holocene Optimum apparently aren’t well enough know to pose sufficient threat as to require cancelling. Yet.

Last edited 4 months ago by John Tillman
H. D. Hoese
March 8, 2021 11:27 am

http://www.realclimate.org/index.php/archives/2021/03/the-rise-and-fall-of-the-atlantic-multidecadal-oscillation/
“A scientist has to admit when they are wrong. Unfortunately for all of us, my colleagues and I weren’t wrong about the unprecedented warming revealed by the now iconic “Hockey Stick” curve, despite the unrelenting attacks on it by climate change deniers over the past two decades. But I was wrong about the existence an internal AMO oscillation when I coined the term twenty years ago” But I was right about the stick?

It appears that the deniers need to please do something about the AMO, still cool on the Texas coast. Might start here from a professional observer (went out at night) about the cold kill. “These turtles were left to die because of the bureaucracy of our government. It’s a federal offense to handle a sea turtle without a federal certification. US fish and wildlife prohibited us from rescuing “cold stunned” sea turtles during this event, because we weren’t trained by federal wildlife handling class.”

This post protected by the iconic “right” to be choatic. Am currently innocent because the last time I touched a cold-killed turtle was in 1989. They were rare then, now all over the bays. Hockey Stick! Both turtles and regulations.

Joe - the non legal expert & non climate scientist
March 8, 2021 11:41 am

Willis comment – “I do enjoy Mann’s implication that he was the discoverer of the AMO phenomenon, when in fact it had been described in detail in 1994 by Schlesinger and Ramankutty, six years before the publication of Delworth and Mann. Also, in the linked Kerr article in Science that Mann refers to above, despite discussing the name “Atlantic Multidecadal Oscillation” in detail, Kerr never says that Mann named the phenomenon … “

Mann’s lies and distortions are perpetual

On Jan 21, 2021 Mann filed a motions for summary judgment in Steyn/NR/CEI/Stimberg law suit.
Virtually every page has 2-3 distortions/lies or misrepresentations.

A partial listing
1) ” the DC court of Appeals sitting enBanc ruled ….
2) he cited 4 court cases claiming all 4 held “x” when only one court even discussed the subject but was not on point so it was inapplicable to the Mann case,
3) filed motion to strike JA curry under the Daubert standard – “as not qualified as an expert”
4) repetitively stated that he was exonerated in all the 8 climategate investigations.

Alan Robertson
March 8, 2021 11:42 am

“I do enjoy Mann’s implication that he was the discoverer of the AMO phenomenon…”

Mann can say that, having won the Nobel Prize and stuff.

Joel O'Bryan
Reply to  Alan Robertson
March 8, 2021 11:57 am

keep in mind the Oslo-committee awarded Nobel Peace Prize (which Mann claims a part of) was largely debased to irrelevance when the committee gave it to Obama for accomplishing absolutely nothing.

The actual Stockholm Nobel Prizes in Physics, Chemistry, Medicine-biological sciences are still very much coveted and signify discoveries and work that withstood scientific rigors of independent verification.

Last edited 4 months ago by joelobryan
Alan Robertson
Reply to  Joel O'Bryan
March 8, 2021 1:07 pm

“…having won the Nobel Prize and stuff”.
————
keep in mind…”
————-
Your enjoinder might have been better spent, reminding me that some number of the “sarc” challenged do visit these pages.

Clyde Spencer
Reply to  Joel O'Bryan
March 8, 2021 1:29 pm

Maybe it should be re-titled “Nobel Get-A-Piece-of-the-Action Prize.”

fred250
Reply to  Joel O'Bryan
March 8, 2021 7:14 pm

Nobel Peace prize become mostly just a meaningless leftist gesture.

You only have to look at some of the most disgusting people who it has been awarded to

eg Yassar Arafat , Al Gore, O-bummer, IPCC

Clyde Spencer
Reply to  fred250
March 9, 2021 9:37 am

Not “meaningless” to those who receive the money for just being politically correct.

AGW is Not Science
Reply to  Joel O'Bryan
March 8, 2021 8:30 pm

It was debased to irrelevance long before that, when awarded to Yasser “Start the “peace” negotiations, we’re running out of ammo” Arafat.

MarkW
March 8, 2021 11:55 am

I guess we can put Mann’s claim to have discovered the AMO right next to his claim to have received a Nobel prize.

Rory Forbes
Reply to  MarkW
March 8, 2021 4:41 pm

I guess we can put Mann’s claim to have discovered the AMO right next to his claim to have received a Nobel prize.

… and right next to the single Bristlecone Pine that told him there was no Medieval Warm Period … (roughly equivalent to Briffa’s half dozen Yamal Larches).

Oldseadog
March 8, 2021 12:07 pm

Lovely image of psuedo-ensembles on the street corner.
But they aren’t smoking ciggies, they are all playing different instruments that are out of tune both with each other and with the tuning fork

Jeff Alberts
March 8, 2021 12:07 pm

I do enjoy Mann’s implication that he was the discoverer of the AMO phenomenon”

Well, he didn’t say he “discovered” the AMO, just that he coined the term.

MarkW
March 8, 2021 12:08 pm

Of course the paper is paywalled.
He has to pay for all those lawsuits somehow.

Reply to  MarkW
March 8, 2021 1:13 pm

Left wing law firms do the job pro bono for Mann….lawsuits are a weapon to shut down opposition.

Rory Forbes
Reply to  Anti-griff
March 8, 2021 4:43 pm

His legal expenses are paid for by his university who don’t want to be sited as co-conspirators in a charge of malfeasance.

Graemethecat
March 8, 2021 12:09 pm

An analysis of state-of-the-art climate model simulations spanning the past millennium provides no evidence for an internally generated, multidecadal oscillatory Atlantic Multidecadal Oscillation (AMO) signal in the climate system and instead suggests the presence of a 50- to 70-year “AMO-like” signal driven by episodes of high-amplitude explosive volcanism with multidecadal pacing.

And there you have it, Mannian Climate “Science” in a nutshell. The output of a computer model is now considered to be evidence, and trumps actual temperature measurements

ResourceGuy
March 8, 2021 12:14 pm

Volcanic eruptions are not cyclical but any long cycle pattern in the data will do when stretching a correlation beyond reason. If they can do that with volcanoes then certainly they can look sideways at individual solar cycles to stretch a point that is not really there. It’s close enough for government work, hand grenades, and Mann models. That phrase extension is a new modern era concept.

Karl Johan Grimstad
March 8, 2021 12:42 pm
AMO comes from the gravitational force of the moon, which pulls a standing tidal wave that brings more and warmer seawater north. sometimes sunspot activities help to temperature rise, hardly from volcanic of activities
ResourceGuy
March 8, 2021 12:45 pm

In this corner we have the coral reefs and in that corner we have Mann models. You can place your bets but I think the poor corals have no chance in the denier camp in a rigged fight.

Clyde Spencer
March 8, 2021 12:46 pm

An analysis of state-of-the-art climate model simulations spanning the past millennium provides no evidence for an internally generated, multidecadal oscillatory … AMO signal in the climate system

An honest broker (or objective scientist) would at least entertain the idea that possibly the models are not trustworthy, or fit for purpose, particularly since they are known to run warm and have a poor reputation for regional forecasts.

ATheoK
Reply to  Clyde Spencer
March 8, 2021 5:44 pm

The moment manniacal claimed the models provided real data and real predictions, their credibility plummeted.

Perhaps manniacal will provide Mark Steyn will more data to support his writing another “disgrace to the profession” book using quotes and complaints from manniacal’s confederates… Most of whom do not really want detailed investigations into their models.

AGW is Not Science
Reply to  Clyde Spencer
March 8, 2021 8:33 pm

…and can’t hindcast if the start date of the model run is changed from the one “tuned” for.

Clyde Spencer
Reply to  AGW is Not Science
March 9, 2021 9:40 am

AGW
That I didn’t know! Thank you. Can you supply me a reference off the top of your head?

AGW is Not Science
Reply to  Clyde Spencer
March 10, 2021 2:15 pm

I can’t, I’m afraid. Guess I should catalogue all the stuff I read…

Alan
March 8, 2021 12:48 pm

Don’t the Alarmists always tell us volcanoes have no effect on climate? I guess unless it serves their purpose?

Clyde Spencer
March 8, 2021 1:00 pm

Something that I don’t think Mann appreciates is that volcanic eruptions, like temperatures, become less reliable as one goes back in time. In particular, until the modern period of satellite observations, scientists were often unaware of small eruptions in remote countries, and even when they were aware that a major eruption took place, they were often not sure just where. Therefore, the veracity of the historical record of eruptions should be taken with a grain of ice.

Geologists have been looking for periodicity in earthquakes and volcanic eruptions for generations, and have been unsuccessful in demonstrating a correlation. About the best that has been done is to assert that there have been periods in the past when volcanic eruptions were so frequent and violent that they caused the extinctions of biota. It is generally accepted that we live in a time when volcanic activity is mild, allowing civilization to flourish.

I think that the barrier Mann has to surmount is to convince volcanologists that not only are eruptions periodic, but that in relatively recent times (geologically speaking) that the period has been about 65 years. If he presents his speculations to actual experts, I think he will have a very difficult time convincing them that he has discovered something that they haven’t.

philincalifornia
March 8, 2021 1:26 pm

Ha ha ha, I kinda guessed he was lying about coining the AMO terminology.

From lying about his Nobel Prize to lying about the AMO. Oh how the mighty have fallen.

Rory Forbes
Reply to  Willis Eschenbach
March 8, 2021 5:33 pm

Of course, the fact that, “Nullius In Verba” is the motto Of The Royal Society, was coincidental … right?

Caligula Jones
March 8, 2021 1:46 pm

Just re-reading Admiral Morrison’s “The European Discovery of America” and the part that stuck out at me is how many fake islands there were in the Atlantic. they were…almost certainly real at the time, of course.

I mean, they’d go on the maps because on one hand, the mapmakers needed them to be there. That, and they just copied each other of course. Kinda like peer review these days, I guess.

Not much different hundreds of years later, really.

March 8, 2021 2:03 pm

Thanks Willis, great work in a short time.
Climate data is not in Latin, it can be accessed and tested.
And found to fail, like this latest Mann-ism.
The volcano data don’t fit the AMO, hypothesis rejected, next.

What fits the AMO (red) much better is the surface (150m) ocean temperatures in the Barents sea (black), as shown by Levitus et al 2009:

https://agupubs.onlinelibrary.wiley.com/doi/epdf/10.1029/2009GL039847

This supports the AMO being a pulsed alternation in the strength of the AMOC bringing warm water to the Arctic.

levitus 2008 fig 2.PNG
dodgy geezer
March 8, 2021 2:15 pm

Mr Eschenbach,
You do not need to find this paper compelling. That is not what it is for. It is much nearer to the mediaeval Church’s explanation for the existence of HUGE volumes of the ‘true cross’ – miraculous multiplication.
We are not dealing with science here – we are dealing with religion and politics. Any variation in climate forcing before 1900 needs to be abolished – this will do it. End of problem.
If you point out any deficiencies in the explanation you are a heretic and must be ignored.
WUWT is losing this battle because it is bringing science to a politico/religious fight…..

Weekly_rise
March 8, 2021 2:19 pm

There seems to be some significant confusion, on this website and others, about what Mann’s paper is actually arguing.

The paper is not arguing that the AMO is not a real feature seen in observational datasets. Rather, it is arguing that the AMO is not the result of internal variability within the system – it is a response to external forcings. Mann is also not arguing that volcanism exhibits a regular periodicity, but that there is an apparent quasi-periodic nature to several major eruptions that leads to the appearance of a periodic cycle in SSTs that has been interpreted as an internal oscillation. Mann’s argument to this point seems extremely compelling to me, and despite the generally dismissive attitudes I’m finding in the skeptical blogosphere, nobody seems to actually be addressing the fundamental argument.

Last edited 4 months ago by Weekly_rise
Reply to  Weekly_rise
March 8, 2021 2:44 pm

You are not alone having read what Mann is arguing. And what you may find compelling isn’t science, but science denying.

fred250
Reply to  Weekly_rise
March 8, 2021 2:47 pm

“seems extremely compelling to me”.

.

That’s because you are gullible, non-thinking, carbon-deranged, brain-hosed moron.

Arguments using climate models are TOTALLY INVALID

Mann’s arguments are VAPID and EMPTY, and hold ZERO scientific worth.

Climate models will always be a straight line without external forcing,

IGNORANCE OF NATURAL CYCLES is built into them.

There is no such thing as the “deniersphere” it is fantasy or those incapable of rational scientific thought.

Tell us what we “deny” that you have real scientific proof for.

Next you will be saying we “deny” Grimm Bros fairy-tales.

Weekly_rise
Reply to  fred250
March 8, 2021 3:05 pm

Hi Fred, I did not introduce the term “denier,” you did. I referenced the “skeptical blogosphere,” which is simply the collection of blogs that discuss and endorse scientific skepticism related to AGW.

Your personal attacks are not productive, and are not appreciated. If you have a substantive response to anything I wrote in my comment above, I’d be happy to engage you in good-faith discussion based on mutual respect.

Derg
Reply to  Weekly_rise
March 8, 2021 3:51 pm

What is strange is that you give Mann any benefit of the doubt. Mann is a known liar and huckster. Very scorn worthy.

Weekly_rise
Reply to  Derg
March 8, 2021 7:32 pm

There is no benefit of the doubt here – Mann has published his work in a refereed journal and it is available for anyone to evaluate. I’ve read the research paper and found it convincing, and have not seen anyone adequately rebut the arguments it presents. That is not to say that the arguments are indisputably true, but that no one is doing a thorough job of disputing them.

fred250
Reply to  Weekly_rise
March 8, 2021 8:56 pm

“There is no benefit of the doubt here”.

.

And that is EXACTLY the problem, your idiotic GULLIBILITY. !

You are too brain-washed to even look rationally about this mickey mann’s farce.

Using the climate models as a “control” is just utter and complete NON-SCIENCE. !

All Mann has shown is the utter lack of skill of the climate models.

Why are you SO DUMB and willfully blind that you cannot see that.

David A
Reply to  Weekly_rise
March 9, 2021 2:02 am

You repeat your error, addressing exactly zero of the cogent criticisms, merely stating an opinion based on ignoring those very criticisms that are well articulated by Willis.

MarkW
Reply to  Weekly_rise
March 9, 2021 7:40 pm

Of course you find it convincing, you want to be convinced.
Anyone who thinks that climate models are proof of anything, has given up all claim to being a rational thinker. Fred’s insults may be a tad over the top, however you unthinking support of Mann and other alarmists has left you open to it.

fred250
Reply to  Weekly_rise
March 8, 2021 6:45 pm

Now watch as you squirm and slither trying to avoid answering the simple question.

Tell us what we “deny” that you have real scientific proof for.

NONE of your comment are productive

You are a wasted space.

The fundamental argument HAS been address, by many people.

Using climate models as a “control” is total and absolute ANTI-SCIENCE NONSENSE.

Sorry your competence level does not rise to basic comprehension.

Weekly_rise
Reply to  fred250
March 8, 2021 7:25 pm

Fred, do please try to mind your manners, your disrespectful tone is unwarranted and brings down the quality of discussion for everyone. The word “deny” was not introduced into this thread until you typed it out – I have never accused anyone of denying anything.

Using climate models as a “control” is total and absolute ANTI-SCIENCE NONSENSE.”

Argument by declaration is not compelling. Why are climate models inappropriate to use in this context? What is anti-science about it? Please be specific in your criticisms.

fred250
Reply to  Weekly_rise
March 8, 2021 9:05 pm

You poor petal !!

I will decide if my tone toward an AGW suckophant is warranted or not. You have to earn respect… and you are FAR from it, going the opposite way, in fact..

Sorry you are so DEVOID of scientific understanding as to not know that MODELS ARE NEVER PROOF OF ANYTHING

Especially not climate model.

The fact you find mann’s arguments “convincing” tells us all we need to know about your scientific understanding.

You are OUTING yourself as a zero-science, brain-hosed, empty sock.

fred250
Reply to  Weekly_rise
March 8, 2021 9:45 pm

“Why are climate models inappropriate to use in this context?”.
.

Your utter gullibility shines through like a putrid sickly green light.

Climate models are UN-VALIDATED against reality.

They are TOTALLY SKILL-LESS when it comes to basically EVERY facet of climate, having ranges so large that anything could be a “prediction”

They cannot predict basic cycles in the Earth system, such as ENSO, AMO, PDO,

…… so why the **** would you consider them as a “contorl” for those features of Earth’s climate !!

They can’t even get temperature projections correct against REALITY.

They are totally worthless for ANYTHING except propaganda.

They are build for contemptible, gullible, brain-washed scientifically-ignorant fools like you to worship.

Grovel on your knees before the almighty MANN ! suckophant !!

Clyde Spencer
Reply to  fred250
March 9, 2021 9:51 am

Fred
I’m no supporter of claims generally made by weekly_rise. However, I do think that you owe him the courtesy of addressing specifically what he says, rather than just insulting him. Insults are generally behavior unbecoming of a gentleman, and certainly don’t advance the understanding of either side.

I’m not suggesting that you should be non-committal, just stick to the facts and point out where and how he is wrong. Anything less, and people are liable to think that you don’t know why he is wrong.

Lrp
Reply to  Weekly_rise
March 9, 2021 12:47 am

Because they are work of fiction

frankclimate
Reply to  Weekly_rise
March 9, 2021 1:25 am

Hi, “Weekly_rise”. Your question is justified. Let’s have a look on the spatial correlation between the observed SST ( Nasa) and the modelled ones:comment image
It’s well known that GCM and ESM do not a brilliant job ( aka a bad one) in the “pattern”. As you can see there is a zero-correlation in the area in question: the extratropical Northern Atlantic. So it seems to be a bad idea to follow from climate models when it comes to this area in the real world.
I hope this satifies your curiosity.

Weekly_rise
Reply to  frankclimate
March 9, 2021 5:23 am

Thanks for this response, FrankClimate. Can you provide more details about what the map is showing? What model experiments/ensemble are being used?

From Mann’s paper he is arguing that models show the spatial and temporal variability associated with the purported AMO when they are externally forced, but that the patterns do not arise in control runs. See, e.g., his Figure 1 and 2 in this RC post.

frankclimate
Reply to  Weekly_rise
March 9, 2021 6:08 am

The map shows what is mentioned in the headline: It compares the observed SST (ERSSTv5, also used by GISS) with the modeled SST ( it’s called “tos” in the model world) of the CMIP5 mean under the RCP 4.5 scenario. All the models are fighting with the modes of the internal variability (iv), e.g. ENSO and AMV and also with the observed pattern of warming which is negligible influenced by the iv. It’s well known that in some relationship the GCM/ESM world has not too much to do with the real world. They also struggle ( if the ECS is too high) with the Temperature contrast NH vs. SH, see https://judithcurry.com/2021/03/05/compensation-between-cloud-feedback-ecs-and-aerosol-cloud-forcing-in-cmip6-models/ . So it seems to be a little overoptimistic to conclude that the AMV is not a result of the iv because GCM/ESM don’t replicate it. They do not replicate so much either.

Weekly_rise
Reply to  frankclimate
March 9, 2021 6:19 am

Wouldn’t a multimodel mean lose a lot of the internal variability unless all of the models are perfectly in phase? That is, the individual models could capture ENSO quite well, but if they don’t all have the same phase for ENSO, the differences would cancel in the mean.

frankclimate
Reply to  Weekly_rise
March 9, 2021 6:44 am

Re: ENSO: there is no one model that replicates the ENSO-phases and it’s origin. Otherwise we would have a working model for ENSO forecasts more than a few month ahead. We don’t.

frankclimate
Reply to  Weekly_rise
March 9, 2021 9:08 am

PS: And yes, the multi model mean shows the response to the forcing, not the internal variability. The conclusion is: in areas where the long term change of the SST doesen’t follow the forcings there mus be iv involved. If the AMO would be a forcing product one would await a better correlation than zero in the area in question.
best

Weekly_rise
Reply to  frankclimate
March 9, 2021 11:03 am

Would we not also expect a low correlation for multidecadal cycles if they are present in the modeled SSTs but simply out of phase? I think a more appropriate approach to identifying the multidecadal signals in model results would be performing some kind of spectral analysis on the models, and looking for correlations between the mean model spectral peaks and observations, as Mann does e.g. here.

David A
Reply to  Weekly_rise
March 9, 2021 1:58 am

It is you that needs a substantial response to this Willis post. As he directly addressed that which you claim to have been ignored.
Instead you ignored every relevant bit of the main post, and of Judith Curry’s cogent critical post.
You are “defending the indefensible” by ignoring the direct criticisms and creating a strawman of skeptical misunderstanding that is simply not there.

Last edited 4 months ago by David A
MarkW
Reply to  David A
March 9, 2021 7:43 pm

According to weekly_rise, it makes sense to him. Therefore, by standard alarmist logic, there is no need to address the criticism that other raise.

Zig Zag Wanderer
Reply to  Weekly_rise
March 8, 2021 5:24 pm

Weekly, you stated:

The paper is not arguing that the AMO is not a real feature seen in observational datasets.

Mann stated:

Today, in a research article published in the same journal Science, my colleagues and I have provided what we consider to be the most definitive evidence yet that the AMO doesn’t actually exist.

Is the AMO a real feature that doesn’t actually exist?

Asking for a friend…

Weekly_rise
Reply to  Zig Zag Wanderer
March 8, 2021 7:21 pm

The patterns associated with the AMO are real patterns in SSTs, but the AMO as an internal oscillation is not a real phenomenon – the patterns arise from external forcing. That is what Mann’s paper argues. Is this clearer for you?

AGW is Not Science
Reply to  Weekly_rise
March 8, 2021 8:45 pm

The paper’s “argument” says it is not a real phenomenon because the models, which contain no information regarding natural climate forces whatsoever, since they wrongfully assume CO2 to be the driver, don’t show it.

Kind of like arguing that there’s no evidence of a 1965 Camaro having an internal combustion engine because a 1965 Camaro matchbox car doesn’t have one in it.

Weekly_rise
Reply to  AGW is Not Science
March 9, 2021 5:26 am

The models do show the patterns associated with the purported AMO when externally forced, they do not show the patterns arising from internal variability. A successful rebuttal of the paper needs to focus on this point, but it seems that everyone is getting caught up in whether volcanic activity is cyclic or not, which is not really the point.

Clyde Spencer
Reply to  Weekly_rise
March 9, 2021 9:58 am

So, are you saying that a non-periodic forcing creates an apparent or pseudo-periodicity? Just how does that come about? Coincidence?

Last edited 4 months ago by Clyde Spencer
Weekly_rise
Reply to  Clyde Spencer
March 9, 2021 11:18 am

I think coincidence is certainly a valid option, here. We are talking about a roughly 40-60ish year pattern in SSTs, so there’s a lot of wiggle room. From Mann’s RC post (bolding mine):

“A spectral analysis of a simple “energy balance” climate model driven with volcanic-only, solar-only, and volcanic+solar forcing (see article) shows that there is indeed a multidecadal spectral peak in the response of surface temperatures to natural radiative forcing and that peak arises from the volcanic forcing alone. We conclude that the apparent AMO-like signal during the last millennium is a consequence of the coincidental multidecadal pacing by episodes of explosive volcanic forcing.

AGW is Not Science
Reply to  Weekly_rise
March 10, 2021 2:19 pm

It is a “model” that assumes things for which there is no empirical support, and is therefore as good at providing “evidence,” or the lack thereof, about ANYTHING as is examining the cracks in cow pies.

MarkW
Reply to  Weekly_rise
March 9, 2021 7:45 pm

The models have yet to be validated, or to provide any correct predictions. Using them as proof is something only someone with no familiarity with how science works, would say.

fred250
Reply to  Weekly_rise
March 8, 2021 9:09 pm

Again, Mann’s paper shows absolutely NOTHING.

His conclusions are based on farcical climate models.. NOT EVIDENCE

He manufactures volcano correlations that are meaningless.

The whole paper is an absolute farce from start to finish, like most of his papers.

But… ….. enough to “convince” a low-science person like you.

TheFinalNail
Reply to  fred250
March 9, 2021 5:41 am

And you haven’t read it, of course.

fred250
Reply to  TheFinalNail
March 9, 2021 11:42 am

Poor rusty nail, hanging on by a threads of corroded thought

MODELS CAN NEVER BE EVIDENCE..

Basic science deludes you !

AGW is Not Science
Reply to  Zig Zag Wanderer
March 8, 2021 8:40 pm

LMFAO!

What tangled webs they weave…

Weekly_rise
Reply to  Willis Eschenbach
March 8, 2021 7:18 pm

Willis, my comment was not directed at you specifically, although I do feel that you have not addressed the primary argument Mann is making – all you have done is breezily dismissed it because it is based on climate models. You might not find the results compelling, but the results are what they are, and cannot be dismissed by mere derision; you cannot replicate the observed oscillations associated with the AMO without invoking external forcing.

A second significant point is that the spatial and temporal patterns of the signal reflect response to tropical volcanic forcing. I cannot find the specific quotation you cite in the text of the study itself, but it is clear in context that Mann is not arguing that the pattern of volcanism is necessarily anything more than happenstance. In a post on RC he says:

“The temporal pattern (Figure 3BC) shows that the major cooling excursions coincide with several of the largest explosive tropical eruptions of the last millennium (e.g. the 1258 CE, 1331CE, and 1453 CE eruptions), which happen to be paced in a manner that projects onto an apparent multidecadal (60-70 year period) “oscillation”.

Bryan A
Reply to  Willis Eschenbach
March 8, 2021 8:50 pm

Either Mann is wrong in his original paper declaring the existence of the AMO andEVERY subsequent paper written on the back of his AMO paper is equally baseless
OR
His latest paper is Wrong and any future papers building off of it are equally baseless
OR
Mann is wrong about being wrong and so can’t be trusted to be right and no one in the scientific community should utilize his research as a foundation for their own papers

Weekly_rise
Reply to  Willis Eschenbach
March 9, 2021 5:42 am

Willis, by “you” I mean the general “you,” not you specifically.

Your analysis of volcanic activity comes to the conclusion that, “Now, is there a cycle in the eruption data similar to the ~ 65 year period of the AMO? Well … kinda. But since each and every signal can be broken down into underlying signals, it may just be by chance.” Which I think Mann would almost certainly agree with. The idea is simply that the ~60 year cycle is just an apparent one because of the spacing of volcanic events.

But more importantly, your post focuses on examining whether there is a cyclic pattern in volcanic activity (and comes away inconclusive), but that is not the focus of Mann’s paper. The main thrust is that model control runs do not show the temporal patterns associated with the purported AMO, while externally forced model runs do. This is the piece I am saying you haven’t adequately addressed, because your only discussion of it is to pish posh it away because it’s based on models, but it’s by far and away the most interesting part of the paper.

Reply to  Weekly_rise
March 9, 2021 9:36 am

Models can only show the result of what input ever. As there is no input “natural variability”, you can’t find any in the results.
As long as CS has no idea about the sources of that variability, you will have wrong results, or you draw wrong conclusions, as Mann did once more.

Mike
Reply to  Weekly_rise
March 8, 2021 8:24 pm

” all you have done is breezily dismissed it because it is based on climate models”

What’s wrong with you? Is it that you can’t read or just refuse to?

Last edited 4 months ago by Mike
fred250
Reply to  Weekly_rise
March 8, 2021 9:19 pm

ROFLMAO

The very fact you you accept anything from climate models , shows just how willfully GULLIBLE you really are.

Models are NEVER proof of anything…

…. especially not UN-VALIDATE suppository, and PROVABLY WRONG climate models that have nothing of natural variability and cycles built into them.

Next you will be saying your “believe” Grimm Bros fairy tales or the screen-play in Warcraft.

Lrp
Reply to  Weekly_rise
March 9, 2021 12:53 am

They are not results

MarkW
Reply to  Weekly_rise
March 9, 2021 7:48 pm

Only someone who knows nothing about science would use models to prove anything.

MarkW
Reply to  Weekly_rise
March 9, 2021 7:50 pm

you cannot replicate the observed oscillations associated with the AMO without invoking external forcing.

Using a model, you can’t replicate …

Your mistake is your belief that not being able to find something in a model, is proof that it doesn’t exist.

TonyG
Reply to  MarkW
March 10, 2021 8:11 am

I could create a model that shows AMO happening without external forcings. Would that be sufficient to prove it?

AGW is Not Science
Reply to  Weekly_rise
March 8, 2021 8:38 pm

The “paper” assumes “models” are a realistic representation of the real world, which is the highest order of nonsense. Mann thinks “evidence” or lack thereof, can be drawn from them. He is a snake oil salesman.

MarkW
Reply to  Weekly_rise
March 9, 2021 7:37 pm

Mann’s “proof” is what is being ridiculed. Mann actually believes that since his model is not able to create an AMO without using external forcings, is proof that the AMO must be from external forces is laughable, and only those who are drunk on the kool-aid would accept it.

ATheoK
March 8, 2021 3:35 pm

Excellent dissection of manniacal’s latest assault on science, Willis!

As Feynman stated:

“If it disagrees with experiment, it’s wrong. In that simple statement is the key to science. It doesn’t make any difference how beautiful your guess is, it doesn’t matter how smart you are who made the guess, or what his name is… If it disagrees with experiment, it’s wrong. That’s all there is to it.”

Manniacal and his magical mystical “analysis of state-of-the-art climate model simulations” fantasies.
They are wrong. That’s all there is to mannical’s AMO fantasies.

WR2
March 8, 2021 3:52 pm

“An analysis of state-of-the-art climate model simulations spanning the past millennium provides no evidence…”

You can stop right there, Mikey. Climate models don’t provide evidence of anything except excessive government grants.

dk_
March 8, 2021 4:43 pm

Wait! Do you mean to say that Science isn’t Settled? How many more things will that guy turn out to be wrong about?

Alan M
March 8, 2021 4:46 pm

Sorry I can’t help it but this is one for Josh

I rather did like the idea of a “pseudo-ensemble”, however … is that a bunch of random computer models hanging out on a street corner smoking cigarettes and pretending to be an ensemble?

John Francis
March 8, 2021 5:26 pm

Hi Willis,

i came across a great quotation from Michael Crichton today. I am reading his novel “Next” talking about scientists:

Page 95:
“The cost of such fraud is enormous,” McKeown said, “estimated at thirty billion dollars annually, probably three times that. Fraud in science is not rare, and it’s not limited to fringe players. The most respected researchers and institutions have been caught with faked data. Even Francis Collins, the head of NIH’s Human Genome Project, was listed as co-author on five faked papers that had to be withdrawn.
“The ultimate lesson is that science isn’t special—at least not anymore. Maybe back when Einstein talked to Niels Bohr, and there were only a few dozen important workers in every field. But there are now three million researchers in America. It’s no longer a calling, it’s a career. Science is as corruptible a human activity as any other. Its practitioners aren’t saints, they’re human beings, and they do what human beings do—lie, cheat, steal from one another, sue, hide data, fake data, overstate their own importance, and denigrate opposing views unfairly. That’s human nature. It isn’t going to change.”

Excerpt From
Next
Michael Crichton
This material may be protected by copyright.

So true!

Sara
March 8, 2021 5:58 pm

I saw this: Figure 1. Long AMO, from NOAA. This shows a period of about 65 years. There are various instrumental versions of the AMO data. This is the longest instrumental version of the AMO held by NOAA, starting in 1856.

And then, owing to Mr. Mann’s prior claims of knowing Everything About Everything (which is completely not true) and discarding what has not suited his notions of stuff happening, I had to avoid falling off my chair and laughing myself silly. It’s quite apparent now that Mr. Mann lives in his own little world, where everything obeys the diktat of “It is if I say it is”, which I have run into in the work world, uttered by people whose egos were threatened when someone tried to correct them.

And to think that he had so much going for him…..

Oh, well. Moving on.

bill hunter
March 8, 2021 6:01 pm

Wow, Mann is good! I am sure with little effort he could statistically validate the butterflies in Brazil causing Tornados in Texas conundrum!

wadesworld
March 8, 2021 7:32 pm

Raise your hand if you’re surprised the person responsible for trying to fake himself a Nobel prize is trying to take credit for naming the AMO. Anyone? Anyone? Bueller?

AGW is Not Science
March 8, 2021 7:55 pm

An analysis of state-of-the-art climate model simulations spanning the past millennium provides no evidence for an internally generated, multidecadal oscillatory Atlantic Multidecadal Oscillation (AMO) signal

Nothing in that statement is “scientifically justified.” See what I did there? Tee-hee!

News flash for “DOCTOR” Mann. No “climate model simulation” (even the vaunted “state of the art” (ROTFLMFAO) ones) provides “evidence” of anything. Evidence is what you get by observation of the real world. A “model” is nothing but a really expensive circle jerk. All it does is reflect the input assumptions of the “programmers.” “Models” provide no evidence. They provide no data. They provide no facts. They provide no insight. They make no revelations. They do not advance human understanding of the natural world one iota. They may occasionally be useful as a “thought experiment” in a strictly academic sense when they are used in a manner that recognizes their limitations, but clearly these morons think the stupid “models” are some kind of “climate oracle.”

I can’t imagine that the fields of “science” have ever seen such an arrogant, conceited, pompous, deluded ass that could even come close to Michael Mann.

John F Hultquist
March 8, 2021 8:44 pm

Some think that volcanism is prompted by unrecognized forces, so ..
I propose these same unknown variables stimulate the water and air to the extent that both the AMO and the volcanoes are synchronized.
All will be clear, in time. {invoking Poe’s law}

– – – –
Thanks, Willis

March 8, 2021 9:08 pm

An approximation with double amplitude 0.3 K and period 64 yr for the net effect of all ocean cycles contributed 16% of planet temperature trajectory. AMO is a major contributor to the net of all ocean cycles. Analysis shows a 96+% match of average global temperature with measured 1895-2020 with only 2 additional contributing factors and no effect from CO2. Most, if not all, of the increase contributed by human activity is from water vapor increase. The analysis is at https://www.researchgate.net/publication/316885439_Climate_Change_Drivers

Aintsm 1850 2020.jpg
Reply to  Willis Eschenbach
March 9, 2021 3:13 pm

W,
Thanks for your comments. Sorry the word doc didn’t make any sense to you. Unfortunately that doesn’t help. I was hoping for something specific. You know, like you usually request “So when you comment, please quote the exact words that you are discussing. This avoids endless misunderstandings.”  If something doesn’t make sense to me and I truly want to understand it, I read it again…and pay closer attention.

I don’t understand what your point is with this: “…when I find a 96+% match between climate datasets…”  I only compared to the HadCRUT4 reported temperatures. It should be the least controversial of the three agencies that report back to before 1900. I expect any of them would give a similar match because the coefficients are adjusted to produce the best match to the measured temperatures. The accompanying graph which shows recent reported temperatures indicates that the main coefficient change would be offset, D. The projections, of course, would apply to the specific trajectory being matched.

Your statement at https://wattsupwiththat.com/2016/07/25/precipitable-water/ “This leads us to a curious position where we have had a larger change in forcing from water vapor since 1988 than from all the other IPCC-listed forcings since 1750 … so where is the corresponding warming?” is what opened the door for me on this issue. I had ruled out non-condensable ghg more than a decade ago from examining Vostok data. http://www.middlebury.net/op-ed/pangburn.html and was looking for what could cause the warming instead of CO2.

As to an elevator speech, I might try this:

Water vapor inhibited the cooling of the planet so that it stayed warm enough for life as we know it to have evolved. Increasing WV, mostly from increasing irrigation, has caused more inhibition to cooling which exhibits as Global Warming/Climate Change. Slight warming from increased CO2 at ground level is countered by increased cooling in the stratosphere with the result that CO2 has no significant net effect on climate.

T TPW CO2 thru 2020 (UAH RSS).jpg
Reply to  Willis Eschenbach
March 10, 2021 2:16 pm

W, The algorithm that produced the results is described in Section 17 (page 32). It does indeed use TPW. (I often simply say water vapor to avoid needing to explain what TPW stands for) The other two factors are an approximation of the net effect of ocean cycles and solar. The 96+% is simply the Coefficient of Determination when the results of the calculation are compared to the reported HadCRUT4 temperatures. The numerical integration step size is one year.

Of course you are right about there not being any useful early TPW data. The first worldwide data started in Jan 1988 by NASA/RSS which I found out about from your WUWT article in 2016. I extrapolated the known TPW data back to 1600 using CO2 as a proxy. The proxy function I came up with results in a match of the slope and magnitude of the known TPW trend in 1988. The resulting curve (Fig 3) looks OK to me given a farm-boy-cum-engineer’s general understanding of the development of irrigation in the world over the years and the increase in rate around 1960 as reported by Aquastat (ref 37). The emphasis on irrigation results from the discovery of its importance in Sect 9. An additional consideration is that the method of calculation places less importance on earlier estimates of TPW.

March 8, 2021 10:10 pm

From the Mann:

The CMIP5 Last Millennium multimodel experiments provide a pseudo-ensemble of N = 16 simulations driven with estimated natural forcing (volcanic and solar, with minor additional contributions from astronomical, greenhouse gases, and land-use change) over the preindustrial period (the interval 1000 to 1835 CE is common to all simulations). We estimate the forced-only component of temperature variation by averaging over the ensemble, based on the principle that independent noise realizations cancel in an ensemble mean.

This trick reveals the study to be a worthless empty tautology. A circular argument just making a prior assumption to “prove” the prior assumption.

Mann assumes that all variation is only two things: forced change and noise. Right from the start. Actual internally generated intrinsic variation was excluded by design. It would have been easy to model that as Ed Lorenz had done in 1963 as “deterministic non periodic flow”. But they didn’t of course.

So the study then finds – unsurprisingly – that all variation is only forced change and noise.

Yes – that was the prior assumption and the study found the prior assumption.

In the same way computer models that are coded to make CO2 cause warming, “discover” that CO2 causes warming.

This study and others like it are circular conjuring tricks having no relevance to the real world.

The study was prevented by design from finding internal dynamic oscillation. It’s hilarious how scared MM and his cronies are of chaotic-nonlinear pattern formation. This paper stinks of that fear.

Last edited 4 months ago by Phil Salmon
Mike
Reply to  Phil Salmon
March 8, 2021 11:47 pm

 It’s hilarious how scared MM and his cronies are of chaotic-nonlinear pattern formation. This paper stinks of that fear.”

100%

ThinkingScientist
Reply to  Phil Salmon
March 9, 2021 4:01 am

Absolutely agree, I commented similarly below. The climate models are simply input forcings (W/m^2) converted to temperature. Yes, they have some temperature distributions over the globe via latitude, land/ocean etc but that could be done in a spreadsheet.

This is why the “signal” matching the temp series is only revealed when you average multiple climate model outputs. The simple model explaining this is that a climate model result over time (t) is no more than:

GCM(t) = forcings(t) * scaling factors + noise

So by averaging many GCM(t) the noise cancels and we get:

Average GCM(t) = forcings(t) * scaling factors

This average output approximates the temperature series observed because the priors already do that by construction.

The proof of this is that the Average (GCM(t)) (and also the temperature obs.) can be reconstructed very, very closely just from the input forcings by linear regression (which calibrates the scaling factors). Therefore the climate models do not add anything to the predicted temperature series output that cannot already be determined from the input priors.

Last edited 4 months ago by ThinkingScientist
Nomad
March 8, 2021 11:58 pm

Piltdown MAAN at it again eh?

March 9, 2021 12:34 am

Isn’t it amazing that all discussion about AMO and its climate impact on the climate takes place without regard on its dimension, temperature and salinity values and structure?  More here: https://1ocean-1climate.com/the-gulf-stream-is-weakening-says-science/
The NA is very cold:
comment image

Ed Zuiderwijk
March 9, 2021 12:50 am

Following the same argument also the ENSO, the La Nina – El Nino cycles does not exist because there is no ‘state of the art’ climate model that provides evidence that such phenomonons are internally generated.

The guy is either delusional or a charlatan. In both cases: why is he in the job he’s in?

oebele bruinsma
Reply to  Ed Zuiderwijk
March 9, 2021 1:45 am

The new reality: In M. Mann’s world, it’s always the humans who are to blame. As climate models are human made, we have the perfect circular reasoning.

ThinkingScientist
March 9, 2021 3:49 am

So far in his career Mann has denied the existence of the MWP, minimised the LIA and now seeks to demonstrate that the AMO is not a quasi-periodic internal variation but an artefact of external forcings.

He “proves” this by referencing a climate model – because the climate model doesn’t produce the AMO, except by inducing it by applying external (prior) forcings based on the combination of aerosol forcing curves and well mixed GHG forcing curves, ergo the model is true and the explanation arrived at. So by a circular argument Mann has arrived at the point where he can argue his sophisticated climate model explains anything he wants.

The problem with this argument (other than the circular reasoning, of course) is that it depends entirely on the input priors to the climate models. Without the input priors (forcing curves) climate models just generate random noise.

By the same logic it is now a simple step to argue that any observation can be explained by adding something suitable into the prior forcing. What’s next – El Nino’s inserted into the priors? Then the models will be almost perfect.

Climate models are basically driven via a reductive decomposition . By creating a series of input prior forcings, the model is driven to give the required output ie match the temperature series. It is self-delusion on a grand scale. The proof this is true is that if we average many models the random behaviour largely cancels and we are left with a temperature response over time. The average temperature response over time can be almost perfectly reconstructed from the input prior forcings, ergo the GCM’s are just lipstick on the pig.

What’s even more incredible is that people believe this crap.

Last edited 4 months ago by ThinkingScientist
D M
March 9, 2021 6:25 am

“In M. Mann’s world, it’s always the humans who are to blame.”

His manntasy is: Humanns save Gaia from humans.

Victor
March 9, 2021 6:46 am

From a comment posted by me a few days ago to the RealClimate blog:

“Once again we see the old, tired “explanation” for the mid-20th century cooling as the masking of an underlying warming trend by industrial aerosol emissions. . .

When we examine temperature records for regions with little or no industrial activity, lo and behold: the expected warming trend fails to appear. Now I have no idea whether or not the “Atlantic Multidecadal Oscillation” is a real phenomenon or an artifact. But using industrial aerosols to explain the very real cooling trend we see from ca. 1940 through ca. 1979 (40 years!) would appear to be a serious error, produced by the failure to invoke the most fundamental scientific controls.

For details, I refer the reader to the following blog post (http://amoleintheground.blogspot.com/2021/03/thoughts-on-climate-change-part-10.html#more ), where I present relevant temperature data for the Arctic, the Antarctic, Africa, Madagascar, Siberia, Afghanistan, Burundi, Haiti, Kyrgistan and New Caledonia. In all cases, the data for the period 1940-1979 fails to reveal any trace of the assumed warming trend, despite the absence of much in the way of industrial activity.”

Predictably, my comment was consigned to their “bore hole” in a crude attempt to divert attention from embarrassing evidence.

donald penman
March 9, 2021 8:02 am

We had slow refreeze this winter in the Arctic and I wonder if this could have meant currents flowing from the Arctic increased the volume entering the North Atlantic. The years since 2007 have been fast freezing up till now as I recall.

Tom Abbott
March 9, 2021 8:54 am

Whatever is causing the ups and downs in the Earth’s temperatures, the AMO temperature profile is repeated all over the world. The AMO profile shows it was just as warm in the Early Twentieth Century as is is today.

Here is the US surface temperature chart (Hansen 1999) which closely resembles the temperatue profile of the AMO.

Other regional surface temperature charts from all over the world show the same temperature profile as the AMO and the US Hansen 1999 chart.

Hansen 1999:

comment image

Weekly_rise
Reply to  Willis Eschenbach
March 10, 2021 6:39 am

Willis, surely you see why your comment is a non-response? Maybe there is something wrong with the models here, and that’s the explanation, but you have not shown that. Why do you believe, specifically, the model control runs don’t show AMO while forced runs do? Can you provide evidence to substantiate your position?

Wim Röst
Reply to  Willis Eschenbach
March 10, 2021 1:11 pm

Willis, this answer is worth a separate post.

(More especially the part starting with I’ve been programming’)

Burl Henry
Reply to  Willis Eschenbach
March 10, 2021 5:05 pm

Willis:

You are blowing smoke.

“Models” cannot model El Ninos or La Ninas because they are caused by random volcanic eruptions, and increasing or decreasing levels of Anthropogenic SO2 aerosol emissions,

Further, there is zero evidence that CO2 has any climatic effect, and any model incorporating CO2 will necessarily fail.

You are doing everyone a great disservice by your failure to recognize the overwhelming effect of atmospheric SO2 levels.

Burl Henry
Reply to  Willis Eschenbach
March 11, 2021 11:23 am

Willis:

I was actually responding to your point #8.

You are normally right on, but in this instance you completely ignored the essentially perfect correlation between changes in atmospheric SO2 aerosol levels, and temperature changes.(of which I have made you aware), and instead described Earth’s climate as being an exceedling complex.system.

It is, in fact, an very simple system, with no cycles of any kind. Add SO2 aerosols, and it cools down. Decrease SO2 aerosols, and it warms up.

Burl Henry
Reply to  Willis Eschenbach
March 11, 2021 6:33 pm

Willis:

You keep calling my analyses a “theory”

The actual theory is that SO2 aerosols are the Control Knob for Earth’s Climate.

The graphical data which I present is PROOF of the theory–every significant increase or decrease in average anomalous global temperatures can be shown to be, or attributable to, changing levels of SO2 aerosols in the atmosphere.

And you are incapable of finding anything of note in my theory!! It is the only proven climate theory in existence.

Weekly_rise
Reply to  Willis Eschenbach
March 11, 2021 6:09 am

“Weekly, I have no idea why the model control runs wouldn’t show a modeled AMO, while when they are forced with some specially selected model forcings they do show a modeled AMO. I also have no idea why model runs don’t show a modeled El Nino, or a modeled AAO, or many natural phenomena.

The curiosity to me is why you would take any of that as evidence about the real-world AMO.”

Willis, I propose simply that this is a thing worth exploring. Mann has developed a hypothesis about why the control runs don’t show an AMO and forced runs do, and he provides a lot of solid evidence supporting it. Simply saying, “I bet the models are wrong, though” does not let us off the hook. If they’re wrong we need to understand why they are wrong and to understand what that tells us about the system. This is what I mean when I say the responses I’ve seen have been inadequate and not compelling.

Your general points about models are well taken, if overly cynical in my view. I’m a strong proponent of the aphorism that all models are wrong, but some are useful.

Weekly_rise
Reply to  Willis Eschenbach
March 11, 2021 1:02 pm

And in fact, regarding your claim that he has a “hypothesis about why the control runs don’t show an AMO and forced runs do”, according to his study the AMO appears in some unforced runs and not in others. Here you go:”

The fact that these two models turned out to be outliers is rather one of the major factors motivating the study, is it not? A primary source of evidence for the AMO as an internal oscillation over paleo timescales came from the fact that extended (1000+ year) control run simulations with these two models show AMO-like oscillations. Mann et al.’s 2020 study shows that control runs with the CMIP5 ensemble do not. This latest paper builds on this finding to show that the apparent AMO oscillations in the paleo record coincide with volcanic forcing.

The CFD models used by Boeing are almost certainly wrong, since a model by definition is a representation of a real system that at some level is too complex to capture in a model. Being wrong doesn’t mean you can’t fly a jumbo jet or land a rover on Mars. Agreed that we have to try to understand why wrong models are wrong – that’s how we improve our understanding. I also agree that it’s extremely hard to figure out why a given model is wrong, which is why so many really smart people spend such an awfully large amount of time trying to do it.

KAT
March 10, 2021 1:06 am

Conjecture possibly explaining the mechanism of the AMO?

1) High tide in the North Atlantic occurs over numerous lines of longitude affecting diverse straits to Arctic ocean (from North Atlantic) for a relatively protracted daily time period. 
This sea water influx to the Arctic ocean is comparatively deep and cold mixture compared to the outflow of warmer surface water at the Bering Strait.
The Bering Strait is 85 km wide at it’s narrowest and only 90 metres deep in places.

Hydraulic tidal pump – Colder water of mixed depth IN to Arctic Ocean from North Atlantic. Warmer surface water OUT to Pacific.
Duration – Relatively LONG time period

2) High tide of extremely short daily duration at Pacific region passing through the narrow Bering Strait from the Pacific into the Arctic Ocean.

Hydraulic tidal pump – Small volume of warmer surface water IN from Pacific to Arctic Ocean. Small amounts of mixed depth water OUT to North Atlantic.
Duration – Relatively SHORT time period.

The overall effect of the above processes would be to eventually create a water temperature imbalance that possibly goes some way to explain the periodic AMO?

Last edited 4 months ago by KAT
Andrew Chantrill
March 10, 2021 3:18 am

The correlation between AMO and UK Sunshine hours (and hence UK temperatures) seems quite solid. Am I missing something?

Andrew Chantrill
Reply to  Willis Eschenbach
March 10, 2021 8:46 am

Willis thank you for your reply. I’m sorry I didn’t make myself clear.

My question is really a) does the increased sunshine cause the AMO (plausible), or b) does the warm phase of the AMO cause more sunshine (how?), or c) are they both manifestations of a third variable (cosmic rays, higher UV solar output etc)?

Andrew

Andrew Chantrill
Reply to  Willis Eschenbach
March 10, 2021 12:22 pm

Thank you; much appreciated!

Andrew