Computational Physics or Process Model
Here’s a zeroth-order cut at differentiating a computational physics problem from working with a process model of the same physical phenomena and processes.
A computational physics problem will have no numerical values for coefficients appearing in the continuous equations other than those that describe the material of interest.
Process models can be identified by the fact that given the same material and physical phenomena and processes, there is more than one specification for the continuous equations and more than one model.
Some processes models are based on more nearly complete usage of fundamental equations, and fewer parameterizations, than others.
Added March 21, 2010
The necessary degree of completeness for the continuous equations, and the level of fidelity for the parameterizations, in process models is determined by the dominant controlling physical phenomena and processes.
Added July 6, 2010
The sole issue for computational physics is Verification of the solution.
Process models will involve many calculations in which variations of the parameters in the model are the focus. None of these parameters will be associated with properties of the material. Instead they will all be associated with configurations that the material has experienced, or nearly so, at some time in the past.
Scientists Create Their Own Communication Problems
Scientists urge Senate action on global warming
In a move to shore up credibility for climate change science, American scientists and economists are asking the Senate to enact immediate legislation to reduce emissions related to global warming.
Two thousand US economists and climate scientists, including eight Nobel laureates, are sending a letter Thursday to the Senate urging lawmakers to require immediate nationwide cuts in greenhouse-gas emissions tied to global warming.
. . .
“We call on our nation’s leaders to swiftly establish and implement policies to bring about deep reductions in heat-trapping emissions,” the scientists write in the letter. “The strength of the science on climate change compels us to warn the nation about the growing risk of irreversible consequences as global average temperatures continue to increase.”
Only the last blockquote is in the letter. But the summary by the writer of the article seems to me to be correct.
Oh, and their own creditability problems, too.
Equilibrium, Energy Balances and Budgets, and Stuff
Recently I ran across the following comments on a blog. The comments are followed by my response.
1.
“The physics of the direct warming effects of increased concentrations of CO2 and other infrared-absorbing gasses is completely clear.”
Let me try, “The physics of radiative-energy transport phenomena and processes given changing compositions of CO2 and other infrared-absorbing gasses in a homogeneous mixture of gases is completely clear.”
In fact, I think this can be expanded to include all radiative-energy transport phenomena and processes, ( absorption, transmission, and reflectance ), for both ultra-violet and infrared radiation, so long as homogeneous mixtures of gases are the material.
For me, one question is, How does this relate to the Earth’s atmosphere, oceans, ice, and land, and all the materials in and on these, and all the phenomena and processes occurring within and between these?
2.
“So, yes, one must combine this measurement of anthropogenic CO2 with the simple radiative physics in the atmosphere to get the fact that we expect AGW.”
The radiative-energy transport phenomena and processes occurring in the Earth’s atmosphere are far from ‘simple’. If these were simple, I think the treatment of them in mathematical models could be fairly characterized as being based on the full and complete fundamental equations associated with these, depend solely on properties of the materials of interest free of any parameterizations, accurate numerical solution methods known and fully incorporated into all GCMs, and resolution of all temporal and spatial scales accurately resolved for every calculation.
So far as I am aware, none of these conditions are met. The parameterizations for some of the phenomena and processes associated with radiative-energy transport in the Earth’s atmosphere are in fact used to tune the GCMs when improvements in hindcasts are needed. The properties of materials as they appear in the fundamental equations for any phenomenon or process are never used as tuning knobs.
I’ll add now, that R. D. Cess, V. Ramanathan, G. E. Thomas, K. Stamnes and a few other people might be surprised to learn of the simplicity of radiative-energy transport calculations in the Earth’s atmosphere. The earth’s atmosphere is not a homogeneous mixture of gases; it’s far more complex. Some of the materials that make the Earth’s atmosphere a heterogeneous mixture of gases, vapor, liquid, and solids have critically important interactions with the radiative energy transport.
Recently, I also ran across this statement in an online kind-of textbook:
“To develop this understanding we must discuss various forms of energetic equilibria in which a physical system may reside. Earth (and the other terrestrial planets, Mercury, Venus, and Mars) are said to be in planetary radiative equilibrium because, on an annual timescale the solar energy absorbed by the Earth system balances the thermal energy emitted to space by Earth.”
My bold.
The writer has specified a time scale over which the in-come and out-go of radiative energy for the Earth’s systems are balanced; ‘annually’. In my opinion there is no foundation whatsoever for this statement. By the same token, I think that this is the first time that I’ve seen any temporal scale attached to the radiative-equilibrium hypothesis. This one is clearly unsupported, however. The Earth’s systems both receive and reject energy on all temporal and spatial scales. Yes, the Earth’s systems, at this very instance, are losing energy to deep space and this seems to be frequently overlooked.
IPCC Peer-Reviewed Literature
This post over at Roger Pielke Jr.’s place, Gray literature in the IPCC, A guest post by Andreas Bjurström is reassuring information for me.
I’ve read ‘peer-review’, ‘peer-reviewed’, and ‘peer-reviewed literature’ just about as many times as I’ve read ‘science’, ‘the science’, and ‘scientists’. I was beginning to doubt the validity of my own, merely engineering related, publication record. I was becoming depressed and thinking that I was unworthy of commenting and that I should follow only the advice of Peer-Reviewed Scientists.
But now I see that my publication record, and all the engineering literature that I have worked with, is more nearly completely peer-reviewed than the real-world standard set by the IPCC. The technical documentation for almost all engineering literature falls under the first column on the left at the post, plus technical reports from the middle column. I will argue that if these technical reports are in any way associated with organizations performing work for government / public agencies, they have been peer-reviewed. And actually reviewed in much more depth than that typical peer-reviewed journal reviews.
Additionally, I think that I can say that the engineering literature is on a much firmer foundation than the IPCC when it comes to peer-review. I have never, for example, cited, ‘articles in the daily papers and magazines’, or lectures, or audio/visual media, or blogs, or preprints, or e-prints. And I’m certain that I’ve not seen these cited in any of the engineering literature that I’ve used in my work. I have, however, cited technical reports from the middle column.
This information is yet another example that certain buzz-phrases have been over-utilized in The Climate Science Community to the extent that they have become, as jstults has noted, merely words and have no real meaning.
Maybe I’ll start working on a Climate Science Bingo scoring pad.
A Milestone
Sometime yesterday Monday March 1, 2010, this blog had its 1000th page view. A state attained by many blogs in a matter of minutes every day. I think this counter is counting from some time in August 2007.
That’s ok. I prefer a small, boutique-ish, highly-focused environment.
The Curry Open Letter on Climate Science
For me, the focus on Towards Rebuilding Trust is not the issue. The general public very likely has some vague overall concepts of the basic nature, characteristics, and properties of science, and the behavior of scientists. The general public, however, has never been directly subjected to results solely produced by a science community.
The critical aspect, in contrast to trust by the general public, is as follows. Policy decisions the outcome of which affect the health and safety of the public are never based solely on the basic concepts of science and scientists. Every one of these outcomes, without exception, have been implemented through independent regulatory agencies of governments. These agencies have been designed first of all to be placed between advocates and the general public. The agencies are also responsible for conducting rigorous, independent, deep, and difficult, review of not only the background science, but more importantly the science, engineering, and technology that is necessary for implementation of products and services. All of these agencies have set in place procedures and processes that must be followed without exception.
Validation is a Process
Why has global warming paused? Water vapor may be in the answer. And here.
Contrary to what seems to be the general impression, radiative energy transport in complex interacting media is not a slam-dunk given. Until the numerical values of the dominant driving potential for the Earth’s climate systems are pinned down, the uncertainties in the response of the systems will continue to be large.
ILL-Posed IVPs and the MMS
The subject means ill-posed Initial Value Problems (IVPs) and the Method of Manufactured Solutions (MMS). I have uploaded two files; this one has the words, and this one has the figures. If you open them in separate windows the text is easier to follow.
All comments, especially corrections for incorrectos, will be appreciated.
Interval Arithmetic
This is a test.
Update January 6, 2010
I have uploaded a file that has additional details about the calculations.
The CRU Info Leak . . .
I’m thinking there just might be some problems in some of the GCM software.
Models Methods Software 