Models Methods Software

Dan Hughes

Testing Energy Balance and Budget

In this previous post, I mentioned the energy budget / balance for the Earth’s systems. Specifically, the fundamental hypothesis for AGW is that human activities have created an imbalance in the radiative-energy transport budget and that an increase in temperature will be obtained in order to return to some kind of, but practically undefined, equilibrium state. A true state of energy in-come = energy out-go is never attained for the Earth’s systems. The daily and yearly cyclic variations are observed easily by direct experience and instrumental means. Especially, neither the out-going infrared energy or the in-coming ultra-violet energy are constant, and are not monotonically increasing or decreasing.
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March 16, 2010 Posted by | Uncategorized | , | 4 Comments

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.

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March 10, 2010 Posted by | Uncategorized | , , | 3 Comments

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.

January 30, 2010 Posted by | Uncategorized | , | 1 Comment

Validation is a Process

AOLBGCM validation is an ongoing process.
Can’t ever do too much of it.

October 9, 2009 Posted by | Uncategorized | , , | Leave a comment

New V&V Book by Pat Roache

I received the following e-mail from Pat Roache regarding his new book about Verification and Validation. He has also made arrangements for reduced prices on two others of his books.

I am pleased to announce the publication of
“Fundamentals of Verification and Validation” by Patrick J. Roache.
Copyright 2009, ISBN 978-0-93478-12-7. 476 pages, subject index.

The book is the successor to my 1998 book “Verification and Validation in Computational Science and Engineering.” About 1/3 of the material is new, including a new Chapter 11 describing the Total Validation Uncertainty approach of ASME ANSI Standard V&V 20 (2009).

The attached file outlines the new features of the book. A complete Table of Contents, including designators for new and modified Sections, will be found on the website.

The price is the same as the 1998 book, U.S. $85.00 (but shipping charges have increased). The book is available directly from our fulfillment house, BookMasters, by email order to

orders@BookMasters.com

or from Amazon.com at the following.
http://www.amazon.com/Fundamentals-Verification-Validation-Patrick-Roache/dp/0913478121/ref=sr_1_7?ie=UTF8&s=books&qid=1253150836&sr=1-7

The orders to BookMasters tend to ship faster since they do not run out of stock. Also, wholesale orders can be placed by contacting BookMasters at orders@BookMasters.com.

I would appreciate it if you would forward this email to any of your colleagues who might be interested.

Thanks for your consideration.

Respectfully,
Patrick Roache

p.s.
If anyone is interested, the 1998 V&V book is on clearance sale for 1/2 price at US $42.50. Available from orders@BookMasters.com or from Amazon at
http://www.amazon.com/Verification-Validation-Computational-Science-Engineering/dp/0913478083/ref=sr_1_4?ie=UTF8&s=books&qid=1253718713&sr=8-4.

Likewise, the book “Fundamentals of Computational Fluid Dynamics” is on clearance sale for 1/2 price at US $37.50. Available from orders@BookMasters.com or from Amazon at
http://www.amazon.com/Fundamentals-Computational-Dynamics-Patrick-Roache/dp/0913478091/ref=sr_1_5?ie=UTF8&s=books&qid=1253718713&sr=8-5

September 24, 2009 Posted by | Calculation Verification, Verification | , , , , , | Leave a comment

V&V and NNSA Advanced Strategic Computing at LANL

[Updated September 26]
I think the name of the program originally known as the Advanced Strategic Computing Initiative ( ASCI ) is now known as Advanced Simulation & Computing ( ASC ).

[Updated August 26]

I have uploaded an excellent summary, developed by Los Alamos, of the ASC V&V Program at LANL. It is here.

A couple of quotes.

Confidence in simulation extrapolation comes via confidence in physics & numerics models, not calibration to experimental data.

Having “good agreement” between calculations and observations is not sufficient to establish scientifically credible predictive capability.

More and more it seems that the Climate Change Community remains the only holdout among all compute-intensive enterprises relative to application of rigorous, independent V&V to computer software.

Update
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August 25, 2009 Posted by | Calculation Verification, MMS, Verification | , , , , , , | 5 Comments

Verification and Validation are Critically Important

Here and here.

June 24, 2009 Posted by | Verification | , | Leave a comment

Black Boxes

Not my kind of Engineering.

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October 24, 2008 Posted by | Verification | , , , | Leave a comment

“an extra thousand code checkers”

Well, GISS/NASA employee Dr. Gavin Schmidt has done it again. He has given direct proof that the fundamental concepts of software Verification and Validation and other Software Quality Assurance procedures are not in the work universe of GISS/NASA.

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September 10, 2008 Posted by | Uncategorized | , , , | 8 Comments

Mass and Energy Conservation

When the basis of the mathematical models used in AOLGCM models/codes are discussed it is almost always stated that the ‘fundamental laws of conservation and mass and energy’ are at the foundations of the models. This is an incomplete, and somewhat incorrect, statement on several levels.

Conservation of mass and energy is the focus of the following discussion.

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August 30, 2007 Posted by | Verification | , , | 6 Comments