PDO/AMO and Global Climate Change

[GaWx]

Depending on how it is calculated, the AMO can be a byproduct of global warming. However, changes in the AMOC independent of global warming probably mean the AMO can be independent of global warming as well.

Depending on how it is calculated, the AMO can be a byproduct of global warming. However, changes in the AMOC independent of global warming probably mean the AMO can be independent of global warming as well.

Skier,

I'm not sure about the gist of what you're saying. Are you implying that the AMO may not exist despite the plethora of evidence presented by scientists in papers? Friv is flat out denying that there's empirical evidence that the AMO actually exists. Are you agreeing with him or not?

[ORH_wxman]

Skier,

I'm not sure about the gist of what you're saying. Are you implying that the AMO may not exist despite the plethora of evidence presented by scientists in papers? Friv is flat out denying that there's empirical evidence that the AMO actually exists. Are you agreeing with him or not?

 

 

AMO denial is semi-popular on some of the alarmist blogs. The claim is that there is an AGW component to the AMO if you use certain versions of it and that all it does is follow GISS temperature. There was a recent paper by Booth et al that tried to claim the AMO variability was a product of aerosols and that the oscillation isn't really internal variability...though that paper was debunked this year by Zhang et al: http://www.ldeo.columbia.edu/res/div/ocp/pub/kushnir/Zhang_etal(AMO-Aerosols)JAS2013.pdf

 

 

 

There is solid evidence that there has been at least semi-periodic oscillation in the AMOC/AMO going back well into the Holocene if one reads up on the literature. The biggest issue some have with it is that we don't know exactly why it changes, so it is natural to try and downplay its existence when we are still unsure of all the physical mechanisms behind it.

 

But again, this topic should really probably be in the other thread.

[Jonger]

Uranium has been around for billions of years, but I don't need to know the history of Uranium to know that it is radioactive.

 

CO2 has been around for billions of years, but I don't need to know the history of CO2 to know that it is a greenhouse gas that keeps the earth warm.

Bad analogy.

This discussion and science is closer to comparing radon to uranium. Radon being CO2 and uranium being water vapor.

Assuming one is poisoning you, identifying the contributions of each is important.

[The_Global_Warmer]

There is no physical evidence of the AMO. 

 

The evidence for the AMO is based on a short SST record which also lags GISS and ENSO, Proxy data, and existing ocean currents.  Proof of the currents is obviously not proof of what the "AMO represents.  Modeling a potential miniscule heat exchange based off the SSTs over the past 150 years to fit ocean currents is not hard but it's not physical evidence.

 

 

If GHG forcing was solely based on correlations and models(that humans programmed to show them the AMO) Opposition to AGW would have already squashed it out of existence  But they can't deny it's physical

 

 

 

The AMO is completely a physical process.  I hate to break it to you all but SSTA over the entire North Atlantic are way to influenced by weather which is influenced by a global climate regime with much more powerful heat transfers than the proposed AMO could ever produced and most of those are fairly minuscule and lack empirical evidence as well.

 

 

Sorry but I don't have to disprove something like the AMO which isn't backed by physical observation of it's mechanism of action. 

 

 

There is a big difference between the AMO being driven anything vs it being solely driven by underwater currents in the Atlantic.

[tacoman25]

There is no physical evidence of the AMO. 

 

The evidence for the AMO is based on a short SST record which also lags GISS and ENSO, Proxy data, and existing ocean currents.  Proof of the currents is obviously not proof of what the "AMO represents.  Modeling a potential miniscule heat exchange based off the SSTs over the past 150 years to fit ocean currents is not hard but it's not physical evidence.

 

 

If GHG forcing was solely based on correlations and models(that humans programmed to show them the AMO) Opposition to AGW would have already squashed it out of existence  But they can't deny it's physical

 

 

 

The AMO is completely a physical process.  I hate to break it to you all but SSTA over the entire North Atlantic are way to influenced by weather which is influenced by a global climate regime with much more powerful heat transfers than the proposed AMO could ever produced and most of those are fairly minuscule and lack empirical evidence as well.

 

 

Sorry but I don't have to disprove something like the AMO which isn't backed by physical observation of it's mechanism of action. 

 

 

There is a big difference between the AMO being driven anything vs it being solely driven by underwater currents in the Atlantic.

 

So basically, you are denying the scientific consensus that the AMO does indeed exist.

[ORH_wxman]

 

There is no physical evidence of the AMO. 

 

The evidence for the AMO is based on a short SST record which also lags GISS and ENSO, Proxy data, and existing ocean currents.  Proof of the currents is obviously not proof of what the "AMO represents.  Modeling a potential miniscule heat exchange based off the SSTs over the past 150 years to fit ocean currents is not hard but it's not physical evidence.

 

 

If GHG forcing was solely based on correlations and models(that humans programmed to show them the AMO) Opposition to AGW would have already squashed it out of existence  But they can't deny it's physical

 

 

 

The AMO is completely a physical process.  I hate to break it to you all but SSTA over the entire North Atlantic are way to influenced by weather which is influenced by a global climate regime with much more powerful heat transfers than the proposed AMO could ever produced and most of those are fairly minuscule and lack empirical evidence as well.

 

 

Sorry but I don't have to disprove something like the AMO which isn't backed by physical observation of it's mechanism of action. 

 

 

There is a big difference between the AMO being driven anything vs it being solely driven by underwater currents in the Atlantic.

 

I guess you still refuse to read what the AMOC is and how it could easily influence North Atlantic SSTs...despite dozens of peer reviewed literature linking you to it over the past couple years. At any rate, you should take this to the AMO/PDO thread...that's a better thread for denying the existence of the AMO than this thread.

[ORH_wxman]

I moved the relevant AMO posts to here from the arctic sea ice thread.

[WE GOT HIM]

User13 I'm sorry to say that you lack the paper education in this field. For example, we don't need to speculate what caused the past glaciations, we know exactly what is responsible.

 

Sundog, I think your very knowledge in this field but I have to disagree with you here. We think we have an idea, but there are so many possible theories, most notably: CO2, plate tectonics, the suns output, distance from the sun, earths axis, the shapes of the ocean, and land distribution. I am sure 20 year from now there will be many more.

[The_Global_Warmer]

Why don't you guys treat AGW DENIERS LIKE THIS?  They deny AGW which is a proven fact through the proven physical testing and observing of the GHG effect in real life.  Yet that doesn't seem to get you guys worked up.

 

I am saying the AMO is not proven to originate from internal variability inside the Atlantic ocean which is a fact.  It's not proven, nor has it been observed. 

 

If the AMO is proven to be mostly from outside the Atlantic. I get the feeling the vigor for it being validated will drop. 

 

 

 

A hypothesis (plural hypotheses) is a proposed explanation for a phenomenon. For a hypothesis to be a scientific hypothesis, the scientific method requires that one can test it. Scientists generally base scientific hypotheses on previous observations that cannot satisfactorily be explained with the available scientific theories. Even though the words "hypothesis" and "theory" are often used synonymously, a scientific hypothesis is not the same as a scientific theory. A scientific hypothesis is a proposed explanation of a phenomenon which still has to be rigorously tested. In contrast, a scientific theory has undergone extensive testing and is generally accepted to be the accurate explanation behind an observation

 

 

 

http://journals.ametsoc.org/doi/full/10.1175/JCLI4174.1

 

 

The physical processes associated with the 70-yr period climate mode, known as the Atlantic multidecadal oscillation (AMO), are examined. Based on analyses of observational data, a deterministic mechanism relying on atmosphere–ocean–sea ice interactions is proposed for the AMO. Variations in the thermohaline circulation are reflected as uniform sea surface temperature anomalies in the North Atlantic. These anomalies are associated with a hemispheric wavenumber-1 sea level pressure (SLP) structure in the atmosphere that is amplified through atmosphere–ocean interactions in the North Pacific. The SLP pattern and its associated wind field affect the sea ice export through Fram Strait, the freshwater balance in the northern North Atlantic, and consequently the strength of the large-scale ocean circulation. It generates sea surface temperature anomalies with opposite signs in the North Atlantic and completes a negative feedback. The authors find that the time scale of the cycle is associated with the thermohaline circulation adjustment to freshwater forcing, the SST response to it, the oceanic adjustment in the North Pacific, and the sea ice response to the wind forcing. Finally, it is argued that the Great Salinity Anomaly in the late 1960s and 1970s is part of AMO.

 

 

 

http://journals.ametsoc.org/doi/full/10.1175/2008JCLI2628.1

 

 

Instrumental sea surface temperature records in the North Atlantic Ocean are characterized by large multidecadal variability known as the Atlantic multidecadal oscillation (AMO). The lack of strong oscillatory forcing of the climate system at multidecadal time scales and the results of long unforced climate simulations have led to the widespread, although not ubiquitous, view that the AMO is an internal mode of climate variability. Here, a more objective examination of this hypothesis is performed using simulations with natural and anthropogenic forcings from the Coupled Model Intercomparison Project phase 3 (CMIP3) database. Ensemble means derived from these data allow an estimate of the response of models to forcings, as averaging leads to cancellation of the internal variability between ensemble members. In general, the means of individual model ensembles appear to be inconsistent with observed temperatures, although small ensemble sizes result in uncertainty in this conclusion. Combining the ensembles from different models creates a multimodel ensemble of sufficient size to allow for a good estimate of the forced response. This shows that the variability in observed North Atlantic temperatures possess a clearly distinct signature to the climate response expected from forcings. The reliability of this finding is confirmed by sampling those models with low decadal internal variability and by comparing simulated and observed trends. In contrast to the inconsistency with the ensemble mean, the observations are consistent with the spread of responses in the ensemble members, suggesting they can be accounted for by the combined effects of forcings and internal variability. In the most recent period, the results suggest that the North Atlantic is warming faster than expected, and that the AMO entered a positive phase in the 1990s. The differences found between observed and ensemble mean temperatures could arise through errors in the observational data, errors in the models’ response to forcings or in the forcings themselves, or as a result of genuine internal variability. Each of these possibilities is discussed, and it is concluded that internal variability within the natural climate system is the most likely origin of the differences. Finally, the estimate of internal variability obtained using the model-derived ensemble mean is proposed as a new way of defining the AMO, which has important advantages over previous definitions.

 

 

 

it's funny to go over so many papers with so many scientists hoping to pin this elusive "AMO".  Hopefully these models account for the Volcano on June 15th 1991.  The stark flip after 1995 created by the Vocano is a bit of an illusion.

 

 

I have not seen one paper say anything about it.

[Snow_Miser]

That's because there are very few people who deny that there is a human component to the warming Friv. They question the magnitude of the human component to the warming, ie how sensitive the climate is to changes in radiative forcing from CO2.

 

Please explain where the multidecadal fluctuations are coming from in the North Atlantic detrended temperature dataset.

 

[ORH_wxman]

Why don't you guys treat AGW DENIERS LIKE THIS?  They deny AGW which is a proven fact through the proven physical testing and observing of the GHG effect in real life.  Yet that doesn't seem to get you guys worked up.

 

I am saying the AMO is not proven to originate from internal variability inside the Atlantic ocean which is a fact.  It's not proven, nor has it been observed. 

 

If the AMO is proven to be mostly from outside the Atlantic. I get the feeling the vigor for it being validated will drop. 

 

 

 

http://journals.ametsoc.org/doi/full/10.1175/JCLI4174.1

 

 

 

http://journals.ametsoc.org/doi/full/10.1175/2008JCLI2628.1

 

 

 

it's funny to go over so many papers with so many scientists hoping to pin this elusive "AMO".  Hopefully these models account for the Volcano on June 15th 1991.  The stark flip after 1995 created by the Vocano is a bit of an illusion.

 

 

I have not seen one paper say anything about it.

 

 

AGW deniers ARE treated like that...anyone who doesn't agree that increased CO2 in the atmosphere causes an increase in radiative forcing is a fool. The debate is mostly about feedbacks and sensitivity. You comparing yourself to an AGW denier is basically all that needs to be said about how much you think of your argument.

 

 

The proposed mechanism of the AMO is the AMOC which is associated with the thermohaline circulation. It varies naturally even if the exact causes are unknown...its based on density of sea water. If you bothered to read upon this, you would stop dismissing these factors as a phony metric.

 

Why don't you read how the North Atlantic varied over the past several thousand years?

http://www.nature.com/ncomms/journal/v2/n2/full/ncomms1186.html

 

Many of these studies are NOT based on models, but on actual proxies.

[chubbs]

Not sure if this paper has been cited before. Indicates that a small portion of arctic sea ice loss in the past 30 years can be attributed to the AMO.

 

http://iopscience.iop.org/1748-9326/7/3/034011  

Sources of multi-decadal variability in Arctic sea ice extent

J J Day1, J C Hargreaves2, J D Annan2 and A Abe-Ouchi3

Abstract

The observed dramatic decrease in September sea ice extent (SIE) has been widely discussed in the scientific literature. Though there is qualitative agreement between observations and

ensemble members of the Third Coupled Model Intercomparison Project (CMIP3), it is concerning that the observed trend (1979–2010) is not captured by any ensemble member. The

potential sources of this discrepancy include: observational uncertainty, physical model limitations and vigorous natural climate variability. The latter has received less attention and is

difficult to assess using the relatively short observational sea ice records. In this study multi-centennial pre-industrial control simulations with five CMIP3 climate models are used

to investigate the role that the Arctic oscillation (AO), the Atlantic multi-decadal oscillation (AMO) and the Atlantic meridional overturning circulation (AMOC) play in decadal sea ice

variability. Further, we use the models to determine the impact that these sources of variability have had on SIE over both the era of satellite observation (1979–2010) and an extended

observational record (1953–2010). There is little evidence of a relationship between the AO and SIE in the models. However, we find that both the AMO and AMOC indices are

significantly correlated with SIE in all the models considered. Using sensitivity statistics derived from the models, assuming a linear relationship, we attribute 0:5–3:1%=decade of the

10:1%=decade decline in September SIE (1979–2010) to AMO driven variability.

[The_Global_Warmer]

That's because there are very few people who deny that there is a human component to the warming Friv. They question the magnitude of the human component to the warming, ie how sensitive the climate is to changes in radiative forcing from CO2.

 

Please explain where the multidecadal fluctuations are coming from in the North Atlantic detrended temperature dataset.

 

 

 

 

You explain it. 

 

Oh wait you can't.

 

 

You can take some guesses.  But you can't explain it.  So why do I have to explain or prove anything?  You guys are guessing, just like all of those people making up models and using proxies from thousands of years ago from one place and some how coming up with data for the entire Atlantic ocean are filling in alot of blanks for such a large spatial region.

 

 

You are the same guy who thinks Argo doesn't have enough data to track OHC.  I doubt you would also believe a couple proxy sites can give us can give us anything near reliable North Atlantic SSTA info for such a large region with detail down to a tenth of a degree Celsius on less than decade time scales.

 

Secondly, why is there not spatial distribution graphics for the AMO like there is the PDO?  So we don't care where warming and cooling are?  Just as long as they show up at the surface inside of 0-70N and 80-0 West.  Which is roughly 8 percent of the Earths surface. 

 

 

The great thing about Science is that until we have an answer the AMO is a still an hypothesis. 

 

 

 

 

Unless I am not getting it how come the North Atlantic SSTs follow GISS so well.  How has Tamino manipulated the data to make it look like this?  Because this explains the changes more than anything else I have seen. Tamino found the AMO to lag GISS no mater how you smooth the data. 

[Snow_Miser]

You explain it. 

 

Oh wait you can't. 

 

 

It's simply explainable as a source of natural climatic internal variability. Obviously, since you deflected the question, you don't have a viable answer for why the detrended Atlantic temperatures exhibit a multidecadal cycle of temperature change.

 

Also, to clarify a misunderstanding, I do believe that ARGO is a fairly reliable Global network of data, but has not been free of instrumentation problems. We can't base solid conclusions based off of a decade of ARGO data. At least, that's what the people monitoring ARGO say.

 

"The global Argo dataset is not yet long enough to observe global change signals."

 

It doesn't make any sense to continue to discuss this with someone who is denying decades worth of research.

[ORH_wxman]

You explain it. 

 

Oh wait you can't.

 

 

You can take some guesses.  But you can't explain it.  So why do I have to explain or prove anything?  You guys are guessing, just like all of those people making up models and using proxies from thousands of years ago from one place and some how coming up with data for the entire Atlantic ocean are filling in alot of blanks for such a large spatial region.

 

 

You are the same guy who thinks Argo doesn't have enough data to track OHC.  I doubt you would also believe a couple proxy sites can give us can give us anything near reliable North Atlantic SSTA info for such a large region with detail down to a tenth of a degree Celsius on less than decade time scales.

 

Secondly, why is there not spatial distribution graphics for the AMO like there is the PDO?  So we don't care where warming and cooling are?  Just as long as they show up at the surface inside of 0-70N and 80-0 West.  Which is roughly 8 percent of the Earths surface. 

 

 

The great thing about Science is that until we have an answer the AMO is a still an hypothesis. 

 

 

 

 

Unless I am not getting it how come the North Atlantic SSTs follow GISS so well.  How has Tamino manipulated the data to make it look like this?  Because this explains the changes more than anything else I have seen. Tamino found the AMO to lag GISS no mater how you smooth the data. 

 

 

The AMO is clearly out of phase in the 1950s, 1980s, and the 1880s/1890s. The AMO has a rough lagged periodicy with the PDO....of course there is going to be a relationship with global temps because those modes of natural variability have an influence on global temps....even moreso in the 19th century and early 20th century than later on givne the weaker anthropogenic forcing back then.

 

 

You haven't provided a single piece of literature that shows the AMO is made up with no physical basis. All you have provided is a graph made by Tamino that shows that the AMO follows GISS on a bit of a lag which makes total sense given that the AMO lags the PDO by a few years and the PDO is a large contributor to global temps.

 

 

I'm guessing you still haven't read up on the AMOC and thermohaline circulation despite numerous attempts to help you along in this educational journey.

[tacoman25]

This is clearly a dogma for Friv. And it's a shame, because being this closeminded about something really hurts his intellectual credibility here. There are many things he has a lot of knowledge about. I don't understand why he refuses, or is unable to comprehend, the existence of the AMO - and yet he acknowledges the PDO. Makes no sense at all.

[Snow_Miser]

 I don't understand why he refuses, or is unable to comprehend, the existence of the AMO - and yet he acknowledges the PDO. Makes no sense at all.

 

It's because the implications are that if the AMO is indeed real, then some of the Sea Ice melt in recent years in the Arctic may very well be due to natural factors. The AMO correlates very well to Arctic Sea Ice anomalies.

 

[SVT450R]

I guess the 13,000 hits in Google scholar on Atlantic Multidecadal Oscilation is a bunch of nonsense i guess these ''SCIENTIST'' are chasing a ghost.

[The_Global_Warmer]

It's simply explainable as a source of internal variability. Obviously, since you deflected the question, you don't have a viable answer for why the detrended Atlantic temperatures exhibit a multidecadal cycle of temperature change.

 

Also, to clarify a misunderstanding, I do believe that ARGO is a fairly reliable Global network of data, but has not been free of instrumentation problems. We can't base solid conclusions based off of a decade of ARGO data. At least, that's what the people monitoring ARGO say.

 

"The global Argo dataset is not yet long enough to observe global change signals."

 

 

 

 

Deflect the question?  Obviously I don't know. 

 

But neither do you.  You're guessing.  How does it not compute to you that you have no evidence of it's existence as an internal oscillation.  You have no causation no defined mechanism of action.  You are therefore assuming, guessing, predicting. 

 

 

 

One of the most suspect things is how long the AMO was negative before the 1930s.  60 years negative, then 40 years positive, 30 years negative(which is also greatly helped out by the June 1991 Volcanic Eruption.) Where it may of turned positive by the late 1980s.  Which would make it closer to 22-25 year negative cycle.  Not even half of the previous "cold" cycle.  Which seemed to trend colder with the solar forcing.  Why would an internal variable oscillation vary that much from one cycle to another?  Is that not just a bit odd?

 

 

 

 

 

Look at the early to mid 1990s.  Amazing.  This is November of 1987 to August of 1995.  We start out with a NINO.  Then we get a Nina until mid 1989.  We can see the effect on the ssta.

below.  Then we get to mid 1991 when a NINO takes over in May.  We see the ssta start to rise.  But then abruptly get stuck in the mud. 

 

Three years the SSTA slowly declined.  Way below their natural projection.  there is no way they would have plummeted like that in 1992 as a strong NINO was in progress and coming to and end.  They should of been closer to .3 to .4C at least.   

 

That entire period would of been much much warmer.  When the end of the Volcano suppressing of forcing ends the SSTA shoot up to .55C for the frist time ever. 

 

 

So this is considered the -AMO not flipping until 1996.  Well I beg to differ when it's clear the AMO signal is royally contaminated during those years. 

 

1987

1.2

1.3

1.2

1.1

1.0

1.2

1.4

1.6

1.6

1.5

1.3

1.1

1988

0.8

0.5

0.1

-0.2

-0.8

-1.2

-1.3

-1.2

-1.3

-1.6

-1.9

-1.9

1989

-1.7

-1.5

-1.1

-0.8

-0.6

-0.4

-0.3

-0.3

-0.3

-0.3

-0.2

-0.1

1990

0.1

0.2

0.3

0.3

0.2

0.2

0.3

0.3

0.4

0.3

0.4

0.4

1991

0.3

0.2

0.2

0.3

0.5

0.7

0.8

0.7

0.7

0.8

1.2

1.4

1992

1.6

1.5

1.4

1.2

1.0

0.7

0.3

0.0

-0.2

-0.3

-0.2

0.0

1993

0.2

0.3

0.5

0.6

0.6

0.5

0.3

0.2

0.2

0.2

0.1

0.1

1994

0.1

0.1

0.2

0.3

0.4

0.4

0.4

0.4

0.5

0.7

1.0

1.2

1995

1.0

0.8

0.6

0.3

0.2

0.0

-0.2

-0.4

-0.7

-0.8

-0.9

-0.9

 

 

 

 

 

 

 

 

 

Another red flag I have is the ESRL folks define and AMO as 80-0W, 0-70N.  The NCAR folks only 0-60N. 

 

 

 

 

This is the North Atlantic SSTS for 80-W, and 60-70N.  We can clearly see arctic amplification at work in concert with ENSO.  This signal is detectable down to 50-55N.  This is just where it is most pronounced.  De-trending the North Atlantic ssts doesn't take out ENSO or arctic amplification or solar influences or ghg influences, or weather pattern influences or aerosol influences. 

 

 

 

 

 

 

 

[The_Global_Warmer]

I guess the 13,000 hits in Google scholar on Atlantic Multidecadal Oscilation is a bunch of nonsense i guess these ''SCIENTIST'' are chasing a ghost.

 

 

So physical proof is no longer prerequisite?  Gotcha.  I guess that proves God is real and the Earth is 6000K years old. 

 

It's sad that you have to resort to something that silly.

 

There are 149,000K hits for The Big Bang Theory in Google scholar.  Which is not proven, guess lots of ghosts chasing going on.

[bluewave]

One of the most suspect things is how long the AMO was negative before the 1930s.  60 years negative, then 40 years positive, 30 years negative(which is also greatly helped out by the June 1991 Volcanic Eruption.) Where it may of turned positive by the late 1980s.  Which would make it closer to 22-25 year negative cycle.  Not even half of the previous "cold" cycle.  Which seemed to trend colder with the solar forcing.  Why would an internal variable oscillation vary that much from one cycle to another?  Is that not just a bit odd?
 

Possibly a combination of volcanic eruptions and the variability of the NAO.

 

http://link.springer.com/article/10.1007%2Fs00382-012-1516-8

 

 

The mechanisms involved in Atlantic meridional overturning circulation (AMOC) decadal variability and predictability over the last 50 years are analysed in the IPSL–CM5A–LR model using historical and initialised simulations. The initialisation procedure only uses nudging towards sea surface temperature anomalies with a physically based restoring coefficient. When compared to two independent AMOC reconstructions, both the historical and nudged ensemble simulations exhibit skill at reproducing AMOC variations from 1977 onwards, and in particular two maxima occurring respectively around 1978 and 1997. We argue that one source of skill is related to the large Mount Agung volcanic eruption starting in 1963, which reset an internal 20-year variability cycle in the North Atlantic in the model. This cycle involves the East Greenland Current intensity, and advection of active tracers along the subpolar gyre, which leads to an AMOC maximum around 15 years after the Mount Agung eruption. The 1997 maximum occurs approximately 20 years after the former one. The nudged simulations better reproduce this second maximum than the historical simulations. This is due to the initialisation of a cooling of the convection sites in the 1980s under the effect of a persistent North Atlantic oscillation (NAO) positive phase, a feature not captured in the historical simulations. Hence we argue that the 20-year cycle excited by the 1963 Mount Agung eruption together with the NAO forcing both contributed to the 1990s AMOC maximum. These results support the existence of a 20-year cycle in the North Atlantic in the observations. Hindcasts following the CMIP5 protocol are launched from a nudged simulation every 5 years for the 1960–2005 period. They exhibit significant correlation skill score as compared to an independent reconstruction of the AMOC from 4-year lead-time average. This encouraging result is accompanied by increased correlation skills in reproducing the observed 2-m air temperature in the bordering regions of the North Atlantic as compared to non-initialized simulations. To a lesser extent, predicted precipitation tends to correlate with the nudged simulation in the tropical Atlantic. We argue that this skill is due to the initialisation and predictability of the AMOC in the present prediction system. The mechanisms evidenced here support the idea of volcanic eruptions as a pacemaker for internal variability of the AMOC. Together with the existence of a 20-year cycle in the North Atlantic they propose a novel and complementary explanation for the AMOC variations over the last 50 years.

 

[ORH_wxman]

So physical proof is no longer prerequisite?  Gotcha.  I guess that proves God is real and the Earth is 6000K years old. 

 

It's sad that you have to resort to something that silly.

 

There are 149,000K hits for The Big Bang Theory in Google scholar.  Which is not proven, guess lots of ghosts chasing going on.

 

 

There's plenty of physical proof for the AMOC and thermohaline circulation...you still haven't read about it, have you? Otherwise you wouldn't be making these statements.

 

I find it interesting that you accept that there is ENSO variability, yet we have no actual definitive proof for what physically drives ENSO. We know its related to sunlight heating deep water in the west Pacific and an atmospheric relation to the trade winds, but we still do not understand the mechanism for the internal variability both on a semi-annual and decadal scale. Why do you not dismiss ENSO since we do not understand the exact process that drives internal variability? According to your prerequisites for a real climate driver, ENSO falls short, so you should be dismissing it.

 

The same applies for the North Atlantic. We know the AMOC is certainly related, but we don't know the exact physical process that drives the variability. We know its been oscillating for thousands of years...unless you do not believe proxy studies....which in that case, it means you do not believe past temperature reconstructions either...making it impossible to know if the recent warming is anything unusual in context.

[bluewave]

A new study provided some clues on forecasting climate shifts in the Pacific.

 

 

The Potential for Successful Climate Predictions!

Hindcast experiments capture long-term climate fluctuations

August 22, 2013/Kiel. Will there be rather warm or cold winters in Germany in the coming years? We may have a long way to go before reliable forecasts of this kind can be achieved. However, marine scientists, under the auspices of the GEOMAR Helmholtz Centre for Ocean Research Kiel, recently managed to successfully hindcast climate shifts in the Pacific. These shifts also have a profound effect on the average global surface air temperature of the Earth. The most recent shift in the 1990s is one of the reasons that the Earth's temperature has not risen further since 1998. The study, published in the online edition of Journal of Climate, shows the potential for long-term climate predictions.

What happened in the years 1976/77 and 1998/99 in the Pacific was so unusual that scientists spoke of abrupt climate changes. They referred to a sudden warming of the tropical Pacific in the mid-1970s and rapid cooling in the late 1990s. Both events turned the world's climate topsy-turvy and are clearly reflected in the average temperature of the Earth. Today we know that the cause is the interaction between ocean and atmosphere. Is it possible to successfully predict such climate shifts? This is the question that scientists, under the auspices of the GEOMAR Helmholtz Centre for Ocean Research Kiel, pursued. Using a coupled model of the ocean and the atmosphere, they were able to successfully replicate these events.

"The ocean plays a crucial role in our climate system, especially when it comes to fluctuations over several years or decades," explains Prof. Mojib Latif, co-author of the study. "The chances of correctly predicting such variations are much better than the weather for the next few weeks, because the climate is far less chaotic than the rapidly changing weather conditions," said Latif. This is due to the slow changes in ocean currents which affect climate parameters such as air temperature and precipitation. "The fluctuations of the currents bring order to the weather chaos".

The researchers used a climate model, a so-called coupled ocean-atmosphere model, which they forced with the observed wind data of the last decades. For the abrupt changes during the 1970s and 1990s they calculated predictions which began a few months prior to the beginning of the observed climate shifts. The average of all predictions for both abrupt changes shows good agreement with the observed climate development in the Pacific. "The winds change the ocean currents which in turn affect the climate. In our study, we were able to identify and realistically reproduce the key processes for the two abrupt climate shifts," says Prof. Latif. "We have taken a major step forward in terms of short-term climate forecasting, especially with regard to the development of global warming. However, we are still miles away from any reliable answers to the question whether the coming winter in Germany will be rather warm or cold”. Prof. Latif cautions against too much optimism regarding short-term regional climate predictions: “Since the reliability of those predictions is still at about 50%, you might as well flip a coin".

Original publication:

Ding, H., R. J. Greatbatch, M. Latif, W. Park and R. Gerdes, 2013: Hindcast of the 1976/77 and 1998/99 climate shifts in the Pacific. J. Climate, http://journals.ametsoc.org/doi/abs/10.1175/JCLI-D-12-00626.1

Links:

www.geomar.de GEOMAR Helmholtz Centre for Ocean Research Kiel

 

[SVT450R]

So physical proof is no longer prerequisite?  Gotcha.  I guess that proves God is real and the Earth is 6000K years old. 

 

It's sad that you have to resort to something that silly.

 

There are 149,000K hits for The Big Bang Theory in Google scholar.  Which is not proven, guess lots of ghosts chasing going on.

My Point is you seem to believe that the AMO doesn't exist or is a false index yet we have 100s of research papers on it so it seems silly for someone as smart as you to bash it's existence.  As Will has pointed out numerous times the Thermohaline circulation plays a role you do understand that it's a large contributor to global climate variability.  As for evidence we have plenty such as tree ring and ice core data to name a few.

[bluewave]

http://curryja.files.wordpress.com/2013/10/stadium-wave.pdf

 

Abstract

A hypothesized low-frequency climate signal propagating across the Northern Hemisphere through a network of synchronized climate indices was identified in previous analyses of instrumental and proxy data. The tempo of signal propagation is rationalized in terms of the multidecadal component of Atlantic Ocean variability—the Atlantic Multidecadal Oscillation. Through multivariate statistical analysis of an expanded database, we further investigate this hypothesized signal to elucidate propagation dynamics. The Eurasian Arctic Shelf-Sea Region, where sea ice is uniquely exposed to open ocean in the Northern Hemisphere, emerges as a strong contender for generating and sustaining propagation of the hemispheric signal. Ocean-ice-atmosphere coupling spawns a sequence of positive and negative feedbacks that convey persistence and quasi-oscillatory features to the signal. Further stabilizing the system are anomalies of co-varying Pacific-centered atmospheric circulations. Indirectly related to dynamics in the Eurasian Arctic, these anomalies appear to negatively feed back onto the Atlantic‘s freshwater balance. Earth’s rotational rate and other proxies encode traces of this signal as it makes its way across the Northern Hemisphere.

[The_Global_Warmer]

 

http://curryja.files.wordpress.com/2013/10/stadium-wave.pdf

 

Abstract

A hypothesized low-frequency climate signal propagating across the Northern Hemisphere through a network of synchronized climate indices was identified in previous analyses of instrumental and proxy data. The tempo of signal propagation is rationalized in terms of the multidecadal component of Atlantic Ocean variability—the Atlantic Multidecadal Oscillation. Through multivariate statistical analysis of an expanded database, we further investigate this hypothesized signal to elucidate propagation dynamics. The Eurasian Arctic Shelf-Sea Region, where sea ice is uniquely exposed to open ocean in the Northern Hemisphere, emerges as a strong contender for generating and sustaining propagation of the hemispheric signal. Ocean-ice-atmosphere coupling spawns a sequence of positive and negative feedbacks that convey persistence and quasi-oscillatory features to the signal. Further stabilizing the system are anomalies of co-varying Pacific-centered atmospheric circulations. Indirectly related to dynamics in the Eurasian Arctic, these anomalies appear to negatively feed back onto the Atlantic‘s freshwater balance. Earth’s rotational rate and other proxies encode traces of this signal as it makes its way across the Northern Hemisphere.

 

 

 

Wow thanks.  This is actually helpful.

[bluewave]

Wow thanks.  This is actually helpful.

 

Sure, the Judith Curry site really expands on the research leading up to the publication of this paper. Both authors

explain how the idea was developed. Marcia Wyatt has a very informative post in the comments section

below the main post.

 

http://judithcurry.com/2013/10/10/the-stadium-wave/

 

 

Marcia Wyatt | October 10, 2013 at 4:52 pm | Reply

Wyatt chiming in here. There are many good points and questions – far too many to fairly address with only a quick peek. I will attempt to give feedback, but please be patient. I am new at this blogging format. I will address some points, as best I can. I’m happy to post something more formal, but first, a bit of background regarding timing of this hypothesis.

This ‘stadium wave’ idea came to me back in 2006. I began work on it and my first presentation to my original dissertation committee brought blank stares, confused looks, and a ‘go-back-and-find-something-we-all-know-about’ response. The data were ‘saying’ not just that one or two oceanic processes were interacting and influencing temperature, but rather that there was a distinct sequence and lag-time between phasings of the indices that made this hypothesis different. I could not ignore this compelling observation; I simply found those in the field who thought similarly and were willing to go this path with me. Additions to my committee included Roger Pielke, Sr, who directly helped guide me at CU. Then there were Sergey Kravtsov and Anastasios Tsonis of the University of Wisconsin, Madison and Judy Curry (GA Tech). That explains where the ideas (for me) started and how they kept going. Getting footing was slow, at best. Peer reviews quite rigorous and unforgiving.

Yes, people have looked at the effect of interacting processes on temperature, but this is not the stadium-wave hypothesis. The hypothesis is based on the idea that indices constitute a network. The network provides communication and stability – in essence, self-organizing. The local coupling allows for signal propagation. And, much like cells working in our intestines, this network communicates by passing along the signal in a very orderly and predictable spatio-temporal format. This basic tenet of the ‘wave’ was presented in the Wyatt et al. paper co-authored with Kravtsov and Tsonis, first available in April 2011. In that paper, we worked with the original indices – the common indices including AMO, NAO, PDO, NINO and a few others. Work on this found and documented the ‘wave’. Statistics can only show relationships; a mechanism was necessary to add credibility. That paper presented findings from numerous other studies, some mentioned by others in this blog, that helped bolster our statistical evaluation/documentation. The current paper with Judy explores the mechanism in great detail. That is the paper’s essence.

To continue the timeline and discoveries: then it was important to see if models could capture the wave. CMIP raw data (SSTs, SLP, etc) were then used to reconstruct those indices we’d used in WKT 2012 (actual publication year in hard copy (Climate Dynamics)). Same procedures used (Wyatt and Peters 2012). Not a single stadium wave was generated. AMO’s low-frequency component was evident, but no connections hemispherically. No index-to-index communication! This is the critical piece of the wave.

What about the past? Then I employed proxy data, caveats acknowledged. I used 300 years worth. There was the wave! Even in the necessarily abridged networks (as not all indices are well represented by available proxies). Now, caveats recognized, but how could this signal keep popping up in all observational/proxy sets but not sets with model-simulated indices? In the proxy sets of 300 years, a very interesting observation surfaced. The amplitude and tempo of the wave changed radically prior to 1800. 1780 seemed to be the most typical dividing line (I used many different proxy data sets). What happened prior to that date? Could be the sun. I don’t know. I can only speculate. But it is interesting that the tempo is what it is now (and since ~1800). Is that purely due to intrinsic mechanisms or could an external source entrain the frequency and nudge it? One could invoke network theory to surmise: if the solar variability does indeed pulse with a multidecadal cadence (as has been suggested by many on these blogs and in recent papers), due to planetary gravitational fields tugging on the barycenter of the solar system, for example, and if the internal variability of the climate network were paced at a similar beat, could solar’s rhythm entrain that of the intrinsic system and nudge the tempo accordingly? And maybe if the solar output is too weak to couple with components of the network, it maybe is unable to entrain the frequency and the system reverts to its intrinsic pace (see Pikovsky for info on networks).

Now Judy mentioned that we got different results based on the solar reconstruction used. That is true, but an important distinction should be made. Using the different Lean and then Wang reconstructions, where the solar constant changes magnitude, did NOT change the results. That is b/c tempo is all that matters in this analysis. To be specific, SHARED tempo. What differed was when we used the updated Hoyt/Schatten, based on five proxies. It pulses similarly to the other reconstruction and to our wave and as the other solar reconstructions, but WHERE it co-varies differs. Phasing differs with this reconstruction. This is a matter for further investigation.

It is noteworthy that the tempo and amplitude of the wave have been relatively consistent over the industrial era, so it is not apparent if or how a CO2-forcing signal might manifest. Again, further investigation required.

And then regarding the detrending: our point in doing so was to highlight MD variability. It may or may not have removed the exact CO2 signature, but with all else noted here (analysis to 1850, to 1700, with models, etc), there is nothing to tell us that CO2 is doing much to change things. But more testing might tell.

When Judy and I worked on this paper, we wanted to really understand dynamics propagating and sustaining the wave. That is the essence of the paper. Please read before presuming. The PR piece was good, but could not capture the full findings of the paper. Evolution of climate regimes through the progression of the stadium wave through the climate network is what is featured in our work.

When I stated for the PR that this neither supports or refutes AGW, that is true. This many-year project has been motivated solely by curiosity about natural variability at this time scale. The fact that the surface temperature is a product of this wave ‘orchestra’ allows us to see that natural component evolve. Combining the wave outcome with an external radiative component, we have an obvious damping or enhancing of the temperature. That is how our work ties in to the AGW controversy.

And answering the PDO question, PDO is ONE component only. The ‘wave’ papers show how PDO on this timescale tends to behave in the regime evolution.

For now, that’s it. I realize this is a string of spontaneous thinking, trying to help clarify what a PR piece inevitably will miss – nature of the format, nothing more. I hope this helps. Our efforts are built upon those of many before us, and we hope we have not omitted any in our lengthy reference list. By not working toward an agenda, we have the liberty to be truly curious and awed!

[Snow_Miser]

Wow thanks.  This is actually helpful.

 

So you believe in the AMO now?

 

http://www.gtresearchnews.gatech.edu/stadium-waves-could-explain-lull-in-global-warming/

 

"Wyatt and Curry identified two key ingredients to the propagation and maintenance of this stadium wave signal: the Atlantic Multidecadal Oscillation (AMO) and sea ice extent in the Eurasian Arctic shelf seas. The AMO sets the signal’s tempo, while the sea ice bridges communication between ocean and atmosphere. The oscillatory nature of the signal can be thought of in terms of ‘braking,’ in which positive and negative feedbacks interact to support reversals of the circulation regimes.  As a result, climate regimes — multiple-decade intervals of warming or cooling — evolve in a spatially and temporally ordered manner. While not strictly periodic in occurrence, their repetition is regular — the order of quasi-oscillatory events remains consistent. Wyatt’s thesis found that the stadium wave signal has existed for at least 300 years."

[Snow_Miser]

I also thought this was very interesting from the link:

 

"The study also provides an explanation for seemingly incongruous climate trends, such as how sea ice can continue to decline during this period of stalled warming, and when the sea ice decline might reverse.  After temperatures peaked in the late 1990s, hemispheric surface temperatures began to decrease, while the high latitudes of the North Atlantic Ocean continued to warm and Arctic sea ice extent continued to decline. According to the ‘stadium wave’ hypothesis, these trends mark a transition period whereby the future decades will see the North Atlantic Ocean begin to cool and sea ice in the Eurasian Arctic region begin to rebound.

 

Most interpretations of the recent decline in Arctic sea ice extent have focused on the role of anthropogenic greenhouse gas forcing, with some allowance for natural variability. Declining sea ice extent over the last decade is consistent with the stadium wave signal, and the wave’s continued evolution portends a reversal of this trend of declining sea ice.

 

“The stadium wave forecasts that sea ice will recover from its recent minimum, first in the West Eurasian Arctic, followed by recovery in the Siberian Arctic,” Wyatt said. “Hence, the sea ice minimum observed in 2012, followed by an increase of sea ice in 2013, is suggestive of consistency with the timing of evolution of the stadium-wave signal.”

 

"The stadium wave signal predicts that the current pause in global warming could extend into the 2030s."

 

This is something that a few on this board have mentioned is a possibility over the next few decades or so. 

[Snow_Miser]

Another paper finds that half of the warming since the 1950s is due to ocean cycles, and thus reduces climate sensitivity to 1.3 Degrees C.

 

http://link.springer.com/article/10.1007/s13143-014-0011-z.