Saturday, October 10, 2009

Reality Clouds climate crystal balls


It is obvious that in any real-life activity it is impossible to wholly rely on such deductions. The reason is at least that the parameters of the studied phenomena are never known absolutely exactly and a small change in parameters (for example, the initial conditions of a process) can totally change the result. Say, for this reason a reliable long-term weather forecast is impossible and will remain impossible, no matter how much we develop computers and devices which record initial conditions.


In exactly the same way a small change in axioms (of which we cannot be completely sure) is capable, generally speaking, of leading to completely different conclusions than those that are obtained from theorems which have been deduced from the accepted axioms. The longer and fancier is the chain of deductions ("proofs"), the less reliable is the final result.

Vladimir Arnold..


In what could be perceived as an about turn in reporting the BBC has separated the "forecasts" for climate to the "reality" that the observations have shown that global warming has stopped

.

This headline may come as a bit of a surprise, so too might that fact that the warmest year recorded globally was not in 2008 or 2007, but in 1998.


But it is true. For the last 11 years we have not observed any increase in global temperatures.

And our climate models did not forecast it, even though man-made carbon dioxide, the gas thought to be responsible for warming our planet, has continued to rise.


So what on Earth is going on?


Climate change sceptics, who passionately and consistently argue that man's influence on our climate is overstated, say they saw it coming.


They argue that there are natural cycles, over which we have no control,


As we see with quasiperiodic systems the return to a “previous climate” state is regularly seen in the NAO.,PDO and IPO. These are sates with long periodicity for a climate regime of warmer then normal or cooler then normal climate states.


The ability for a recurrent periodic state such as the PDO or an inverse temperature “state” is in essence a binary transformation or bifurcation.. The transformation as a velocity inversion has the same effect as a time inversion, (v to - v ) (t to - t )


A fundamental consequence of the aperiodicity of the atmospheric and climate dynamics is the well-known difficulty to make reliable predictions.Contrary to simple periodic or multiperiodic phenomena(such as eclipses,tides ets) for which a long term prediction is possible, predictions in meteorology and climate are limited in time.


The most plausible (and currently admitted) explanation is based on the realization that a small uncertainty in the initial conditions used in a prediction scheme (usually referred as error") seems to be amplified in the course of the evolution. Such uncertainties are inherent in the process of experimental measurement, The uncertainty being in the “closeness of the boundary to the point of bifurcation, and the error in linear equations.” An important aspect discussed by Arnold and Shulinov.


As the “natural variability” and inverse regimes are often accompanied by inverse temperature states always and everywhere(except in gcm predictions) explanations are clearly in order.



5 Comments:

Anonymous Anastassia Makarieva said...

Regarding changing axioms in science, perhaps you might be interested in following the story of Makarieva et al.'s paper in ACPD which did not make it to ACP. To have an idea of the scale of the authors' claims read the authors' final response here:
http://www.cosis.net/copernicus/EGU/acpd/8/S12426/acpd-8-S12426.pdf, pp. 12442-12447 (it is published as an Appendix to the final editor's comment).

In brief, a novel mechanism for wind generation is proposed based on condensation of water vapor. Condensation reduces the weight of air column, hence a horizontal pressure gradient with pressure decreasing towards the region of condensation.

The reviewers ignore the effect of weight and say pressure does not decrease upon condensation, but increases due to temperature rise as latent heat releases. Makarieva et al. consider these arguments, shared by the entire ACP Executive Committee, incorrect.

And indeed, speaking generally, how can weight reduction be overwhelmed by whatever change of temperature? Warm a narrow air column containing 1 kg air by as many degrees as you wish -- it will still weigh 1 kg, so its pressure at the surface will remain the same due to the pressure=weight hydrostatic equilibrium equality.

Are there interested physicists somewhere on Earth who would be willing to enter the meteorological debate? Recent results of Makarieva & Gorshkov in Physics Letters A show an impressive potential for the new approach.

10:04 AM  
Blogger maksimovich said...

Good Morning Dr Makarieva

I have been following this with some interest, and the continuing discussion on Ontogenic growth rates(West et aL etc)

Somewhat coincidentally,I have been going to do a series of posts,on the perceived distance between theory and models,and the transformation where models (experiments)are theory and inconsistencies in the models are some hesitancy on the part of nature,and not incompleteness of the physical description or as you suggested "Information entrophy" Brillouin,L.1956.

Inadequacies in the physical models is seen in what I term the meteorological paradox,as measurements,computer power and models have developed the error or divergence in the forecast has not reduced it has increased. eg Nicolis and Nicolis Foundations of complex systems page 223

This is evident when seen in the evolution of the weather forecast model ability of the ECMWF.A widely used model producing forecasts in the range for a few days to a number of weeks. The preparation base is a n-day forecast with n= 10 days of the global atmospheric state.

In any forecast there is an error dependent on initial conditions (due to arbitrary assumptions/estimates of unknown qualities) with the ECMWF model over the last 20 or so years in a paradox the model error has increased.

In 1982 in a seminal paper in which ECMWF data was first used ,to measure predictive ability. Edward Lorenz found the mean error evolution (doubling time of initial error) was two days, presently has dropped to 1.2 days.

This suggest that there is a limiting of predictive capabilities for long range weather forecasting with models of increasing sophistication ,owing to interconnected complexity in the atmospheric dynamics.

Sensitivity to the initial conditions-the principle signature of deterministic chaos-is thus not an artifact arising from when lower order models are used but is, rather, deeply rooted in the physics of the atmosphere.


Similar findings in Orrell 2002

The atmosphere is often cited as an archetypal example of a chaotic system, where prediction is limited by the models sensitivity to initial conditions (Lorenz, 1963;Pool, 1989). Experiments have indeed shown that forecast errors, as measured in
500 hPa heights, can double in 1.5 days or less. Recent work,however, has shown that, when errors are measured in total energy, model error is the primary contributor
to forecast inaccuracy (Orrell et al., 2001).


One would conclude that there is either an incompleteness in the description, or the physical (mathematical axioms are illposed which would seem to be the case.

At first glance it would seem the ACPE has followed the 'partyline" so to speak and by collusion accepted what is termed a "schoolboy howler"

When ever new or competing theories that challenge the “status quo” of existing scientific theory, we see the enigma of the existing “establishment” refuting the competitor to retain their oligarchial “market” share threatened by paradigm shifts.

Or as Alven puts it

"Scientists tend to resist interdisciplinary inquiries into their own territory. In many instances, such parochialism is founded on the fear that intrusion from other disciplines would compete unfairly for limited financial resources and thus diminish their own opportunity for research."

I will circulate and open some discussion on the Acpd problem and Physica A but be prepared for some robust discussion msuch will be illfounded such as Meesters comments.

4:08 PM  
Blogger Anastassia said...

Thank you for your feedback and interest. I have followed some of your arguments here and there. The story of the ontogenetic growth model is informative in many respects.

Our critique of West et al. dates back to 2002, when a relevant comment of ours was submitted to and rejected by Nature, then to and by Ecology Letters. It was ultimately published in Ecological Modelling in 2004. In 2004 we also published a short comment in Ecology on Brown et al.'s MacArthur's Award paper, where cited this work "in press". Still that did not evoke any reaction from the authors. In 2006 their group published a paper in Functional Ecology where, without citing our work, they explicitly responded to our concern about their incorrect interpretation of Em (energy to build 1 g biomatter) insisting that it is equal to the energy content of biomatter.

After that I had a few other occasions to share our concerns with specialists. But it was only in 2008 in American Naturalist that this group explicitly admitted the error (Moses et al. 2008) and cited our paper. At the same time in their latest publication in Science (Hou et al. 2008) they admit that the original model is wrong almost in our own words, but do not cite our work as the source where the error was pointed out. Instead, they cite their own incorrect model (ref. 7). We asked Science for a corrigendum, implying that might be a misprint rather than an intellectual expropriation, however, to no effect. But they nevertheless published our comment.

As I currently work in two very different worlds, biology/ecology and climate, I would say from my experience biologists are definitely more receptive and ready to discuss things. There are different opinions and competing groups.

Thank you for your deliberations. We are used to being treated harshly and are not afraid of it. As Alexandre Pushkin said, in my poor translation:

So far I am not used to friendliness.
Its kind language sounds strange to me.

Regarding uncertainties in models, one issue that surprises me most is the so-called "model ensemble", so popular in recent years. I spoke to some meteorologists, they believe that if they take several slightly different models (ensemble) and compare their predictions, they will have an idea of uncertainties. Or, even better, let us average the models' predictions, and take the ensemble's average.

It is like models are allowed to vote; then the vote is counted and the decision taken. To go further, each model should be weighted by the number of Scopus citations, to reflect the authority of its authors. I asked -- but what if all models, that are all conceptually similar, are wrong in some physical principle? The answer was, with a smile referring to my ignorance, oh, that's highly unlikely, they are so many...

6:28 AM  
Blogger maksimovich said...

Good Afternoon Anastassia

You and your team have posed some questions which are not without precedent.Unfortunately this is now more the norm then the singularity.

A number of well cited papers now on careful perusal seem to be not as "robust" as the authors conclude.Rebuttal is a major problem,and when the authors correct their error,as found without citation eg Steig et al .

I have come to a conclusion, that science especially in the west, has reverted to "cookbook" science where they "rebake" the same cake year after year,and yet due to uncertainty it still has a dip in the middle.

The arguments have all become circular,divergence in the models shows that uncertainty is increasing, with each additional (and usually unqualified) parameter and still they can justify the "probalistic assumptions"

This circular scientific reasoning brings no "steplike" progress to the underlying theory it promotes inertia.

I did a post here where Tommy Gold explains how the 'interbreeding in disciplines' lowers the genepool and how the crossover promtes evolution.And Tommy Gold has been proven to be correct in most of his controversial works.

One of the Great controversies is how the “closed shop” of scientific review for publication and funding can lead to the passage of scientific consensus into blind cul-de-sacs of scientific theory .Indeed we can cite many Nobel laureates who when questioning the ‘Paradigm” were treated with contemptuous ridicule from the “consensus club”

Thomas Gold cited the behavior of the Nasa consensus of ‘in-house peer review”as the closed herd.

"Another area where it is particularly bad is in the planetary sciences where NASA made great mistakes in the way in which they set up the situation. NASA made the grave mistake not only of working with a peer review system, but one where some of the peers (in fact very influential ones) were the in-house people doing the same line of work. This established a community of planetary scientists now which was completely selected by the leading members of the herd, which was very firmly controlled, and after quite a short time, the slightest departure from the herd was absolutely cut down. Money was not there for anybody who had a slightly diverging viewpoint. The conferences ignored him, and so on. It became completely impossible to do any independent work. For all the money that has been spent, the planetary program will one day be seen to have been extraordinarily poor. The pictures are fine and some of the facts that have been obtained from the planetary exploration with spacecraft - those will stand but not much else."


Dyson reached a similar conclusion,and his interchanging between disciplines brought much to increased understanding.

Now returning to our mutual ares of interest,the interconnection of Climate and the Biosphere which are interconnected,and are integrated.

My pathway (and not my primary area of research)is in the interrelationship between energy transfer at the molecular interface and the selectivity of these molecular motors to various radiations.

The response seems to be at an evolutionary level and as this seems to be irreducible,the focus will be on the evolving strategies of the organisms.

Now to return to your position,the ontogenic model debate is an excellent contemporary discussion that will invoke a wide response and debate,

I will also do some posts on this,the Hess paper was an excellent argument.

12:59 AM  
Blogger 123 said...

It is rather interesting for me to read the post. Thank you for it. I like such topics and anything connected to this matter. I definitely want to read more soon.
Alex
Cell blocker

7:39 AM  

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