Internal Variability=Weather and Numerical Artifacts
This post is based on some notes related to verification and numerical artifacts that I made back in early July.
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V&V and SQA: Part 3, Verification
Verification Activities
The focus of verification is the actual coding of the software with objectives to determine: (1) that the coding corresponds to the equations given in the specification document, (2) the order of accuracy of the numerical methods, and (3) the order of convergence of the numerical methods. In general, the latter two objectives are purely mathematical and go to the heart of the coding of the solution methods. Several of the procedures that are used to pursue these objectives are given in the following discussions.
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V&V and SQA: Part 5, SQA
Software Quality Assurance Procedures
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V&V and SQA: Part 2, Requirements for Production-Grade Software
The requirements for release of software for production-grade applications include:
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V&V and SQA: Part 1, Definitions and Characterization
I’m going to post a series of short summaries of some of the central aspects of verification, validation ( V&V ) and software quality assurance ( SQA ) for production-grade computer software. These subjects have received significant investigations starting in the 1980s ( more or less ) and have reached maturation and have been successfully applied to a wide range of scientific and engineering software. I don’t intend to give a complete exposition of the subjects, the field is much too big.
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Ensemble of Models
There’s a fundamental problem with the ensemble of GCM models approach used in climate science.
Updated 15 August 2010. See below.
The Clausius-Clapeyron Equation
Much is made about the exponential dependency of the vapor pressure of water as a function of temperature. The implication being, as I understand it, that the Clausius-Clapeyron equation implies that there will be significant additional amounts of water vapor in the atmosphere as the so-called global-average surface temperature increases.
Updated November 27, 2010:
For some reasons unknown to me, this post has gotten a lot of hits. But, as noted back in September, nobody is saying anything. Maybe nobody actually reads the post ?? Maybe it’s completely wrong ??
Updated September 17, 2010. At end of the post.
Updated November 2, 2010:
Here’s a recent review of condensation of a vapor from a non-condensable plus vapor mixture: CONDENSATION FROM A VAPOR-GAS MIXTURE
Entropy
Here’s some recent info on a topic that arises from time to time.
I ran across this issue of Philosophical Transactions of The Royal Society B: Biological Sciences, May 12, 2010; 365 (1545):
Theme Issue ‘Maximum entropy production in ecological and environmental systems: applications and implications’ compiled and edited by Axel Kleidon, Yadvinder Malhi and Peter M. Cox. doi:10.1098/rstb.2010.0018
Full papers are available at no cost.
While tracking down more free articles I found this review:
Axel Kleidon, “Nonequilibrium thermodynamics and maximum entropy production in the Earth system: Applications and implications” Naturwissenschaften (2009) 96:653–677. DOI 10.1007/s00114-009-0509-x
This paper:
G Grinstein and R Linsker, “Comments on a derivation and application of the ‘maximum entropy production’ principle” 2007 J. Phys. A: Math. Theor. 40 9717. doi:10.1088/1751-8113/40/31/N01
reports errors in these recent papers by Dewar:
Dewar R 2003. “Information theory explanation of the fluctuation theorem, maximum entropy production and self-organized criticality in non-equilibrium stationary states” J. Phys. A: Math. Gen. 36 631. doi: 10.1088/0305-4470/36/3/303
Dewar R C 2005, “Maximum entropy production and the fluctuation theorem” J. Phys. A: Math. Gen. 38 L371. doi: 10.1088/0305-4470/38/21/L01
Models Methods Software 