Models, Methods, Software

A quick look at some of the info provides evidence that an Independent organization to Review and Verify all results, each and every number, that are to be used to set public policy is critically important.

Climate policy remains the sole exception to this world-wide universal standard.

The present system has been fatally compromised by the very organizations that resist Independent Review and Verification.

Maybe we’ll soon see a govrenment-level Carbon Regulatory Agency approach designed and implemented in a progressive country.

Steve McIntyre has discovered and presented yet another problem with a long-term temperature reconstruction: Yamal: A “Divergence” Problem. While Steve has named his blog ClimateAudit, in my opinion his work is in fact Independent Verification.

The old, and rapidly becoming tedious, “Peer Review Publication is Required” nonsense has already appeared in the comments. Ironically, it seems that no one who raises this issue is aware that Steve is in fact discovering problems in peer-reviewed publications.

A very short summary of a major problem area relative to this olde rant follows.

Read the rest of this entry »

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

[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
Read the rest of this entry »

Here and here.

I sent a slightly revised copy of the comment on the Proposed CO2 Ruling, given in this post, to Ms. Lisa jackson, Administrator of EPA. The letter to Ms. jackson is shown below. I received a reply from Rona Birnbaum, Chief, Climate Science & Impacts Branch, Climate Change Division. (The actual signing of the letter was a task delegated to someone whose name I can’t read.)

As in all previous cases in which I have attempted to convey the critical necessity of Independent Verification and Validation to persons outside the software development community, I failed again. It is obvious that Ms. jackson, Rona Birnbaum, or whoever read and responded to the letter, have no idea what I’m talking about.

Read the rest of this entry »

I have started working on a toy model and plan to include analytical sensitivity analysis as part of the methods.  These notes, and an associated extended discussion that I have up-loaded, serve as a short introduction to the subject.

The file is here:

Summary

These notes introduce a few of the ideas and concepts associated with sensitivity analysis for algebraic and ordinary differential equations. By sensitivity I mean what are the effects of changes in the numerical values of the parameters in a system of equations relative to a response function of interest. The response function can take any mathematical form, but I will focus on the values of the dependent variables of the equation system.

Read the rest of this entry »

The focus on this previous post was the fact that approximations made at the continuous-equation level mean that the model’s mass and energy budgets are different from the mass and energy budgets of the physical system. Note that there are very significant additional issues associated with the discrete approximations applied to the continuous equations and the numerical solutions of these. These issues in the discrete domain, in my opinion, have the potential to far outweigh issues in the continuous domain. Accurate integration of the discrete approximations over the enormous times scales of interest is a very tough problem.

The present post looks at some more issues associated with energy conservation in the discrete domain.

Read the rest of this entry »

it is not even viscous dissipation. There is also an energy imbalance in the NASA/GISS ModelE code due to the error in the ‘viscous dissipation’. The energy imbalance is about the same magnitude as the imbalance associated with increased concentrations of CO2 in the atmosphere.

Updated January 14, 2009, down near the end.

Read the rest of this entry »

This post is a continuation of discussions of the modeling of viscous dissipation in GCMs. The issue has recently come up again over at Lucia’s Blog in this thread. The thread at Lucia’s is related to the posts on this Blog here, here, and here. I have also in the past commented on the issue at Climate Audit, Professor Pielke Sr.’s Climate Science, and Real Climate. The dissipation questions come up now and then in several Blogs.

Read the rest of this entry »