Category Archives: climate models

UQ

Posted on April 17, 2012 | 159 Comments

by Judith Curry

The new International Journal of Uncertainty Quantification has some very interesting papers.  Lets take a look at a paper entitled ‘Error and Uncertainty Quantification and Sensitivity Analysis in Mechanics Computational Models.’

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Posted in climate models, Uncertainty

Assessing climate model software quality

Posted on April 15, 2012 | 287 Comments

by Anonymous

[O]ur notion of software quality with respect to climate models is theoretically and conceptually vague. It is not clear to us what differentiates high from low quality software; nor is it clear which aspects of the models or modelling processes we might reliably look to make to that assessment. 

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Posted in climate models

U.S. weather prediction: falling behind

Posted on March 30, 2012 | 81 Comments

by Judith Curry

“It’s a national embarrassment. It has resulted in large unnecessary costs for the U.S. economy and needless endangerment of our citizens. And it shouldn’t be occurring.

What am I talking about? The third rate status of numerical weather prediction in the U.S. It is a huge story, an important story, but one the media has not touched, probably from lack of familiarity with a highly technical subject. And the truth has been buried or unavailable to those not intimately involved in the U.S. weather prediction enterprise.” —  Cliff Mass, UW

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Posted in climate models

What can we learn from climate models? Part II

Posted on March 1, 2012 | 279 Comments

by Judith Curry

In my original essay on this topic October 2010, my short answer to this question was “I’m not sure.”   My current thinking on this topic reframes the question in the context of fitness for purpose of climate models across a range of uses and applications.

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Posted in climate models

Self-organizing model of the atmosphere

Posted on October 17, 2011 | 216 Comments

by Frank Lemke

A recent post in our Global Warming Prediction Project discusses the question “What Drives Global Warming?” based on a self-organized interdependent nonlinear dynamic system of equations of 6 variables (ozone, aerosols, clouds, sun activity, CO2, global temperature). It also predicts using this system global warming 6 years ahead (monthly resolved) and it compares the known IPCC AR4 projections with this system prediction and the observed anomalies of the past 23 years.

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Posted in Attribution, climate models

Verification, validation, and uncertainty quantification in scientific computing

Posted on September 25, 2011 | 335 Comments

by Judith Curry

I think I am gaining some insight into the debate between scientists versus engineers regarding climate model verification and validation.

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Posted in climate models, Uncertainty

Climate models as ink blots

Posted on September 18, 2011 | 329 Comments

by Judith Curry

From Roger Pielke Jr.:  A fundamental problem with climate science in the public realm, as conventionally practiced by the IPCC, is the essential ink blot nature of its presentation. By “ink blot” I mean that there is literally nothing that could occur in the real world that would allow those who are skeptical of scientific claims to revise their views due to unfolding experience. That is to say, anything that occurs with respect to the climate on planet earth is “consistent with” projections made by the climate science community. 

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Posted in climate models, Prediction, Uncategorized

Santer on timescales of temperature trends

Posted on September 12, 2011 | 350 Comments

by Judith Curry

Santer et al. have a new paper in press entitled “Separating Signal and Noise in Atmospheric Temperature Changes: The Importance of Time Scale.”

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Posted in Attribution, climate models

Water: too little, too much

Posted on August 27, 2011 | 149 Comments

by Judith Curry

Next week, I will be in Boulder attending a workshop on the topic of understanding and predicting conditions associated with either too much or too little water.

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Posted in Climate change impacts, climate models

Should we assess climate model predictions in light of severe tests?

Posted on August 18, 2011 | 382 Comments

by Judith Curry

This question is posed and addressed in a recent article by Joel Katzav in EOS.

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Posted in climate models

reanalyses.org

Posted on August 17, 2011 | 134 Comments

by Judith Curry

How do you estimate the state of the global atmosphere and ocean when observational data sets are incomplete, imperfect and noisy?

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Posted in climate models, Data and observations

NASA Earth Science Advisory Subcommittee

Posted on May 11, 2011 | 124 Comments

by Judith Curry

This week I am attending a meeting of the Earth Science Subcommittee of the NASA Advisory Council.  As described in the Public Notice for the meeting, the topic of this meeting is evaluation of NASA’s  Earth Science Modeling and Activities.

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Posted in climate models

NCAR Community Climate System Model Version 4

Posted on May 8, 2011 | 482 Comments

by Judith Curry

A new paper describing the latest version of the NCAR climate model has just been published at the Journal of Climate.  This is the version of the model that is being used for the IPCC AR5.

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Posted in climate models

Separating natural and anthropogenically-forced decadal climate variability

Posted on April 7, 2011 | 524 Comments

by Judith Curry

The issue of separating natural from anthropogenically forced variability, particularly in context of the attribution of 20th century climate change, has been a topic of several previous threads at Climate Etc.  The issue of natural vs anthropogenically forced climate variability/change has been a key issue of contention between the climate establishment and skeptics.  There are some encouraging signs that the climate establishment is maturing in their consideration of this issue.

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Posted in Attribution, climate models

Nonlinearities, feedbacks and critical thresholds

Posted on February 3, 2011 | 138 Comments

by Judith Curry

Juoakola spotted an interesting paper, that I missed when it was originally published:

NONLINEARITIES, FEEDBACKS AND CRITICAL THRESHOLDS WITHIN THE EARTH’S CLIMATE SYSTEM

JOSÉ A. RIAL , ROGER A. PIELKE SR., MARTIN BENISTON , MARTIN CLAUSSEN, JOSEP CANADELL , PETER COX, HERMANN HELD , NATHALIE DE NOBLET-DUCOUDRÉ , RONALD PRINN, JAMES F. REYNOLDS and JOSÉ D. SALAS

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Posted in climate models, Sensitivity & feedbacks

Scenarios: 2010-2030. Part I

Posted on December 23, 2010 | 437 Comments

by Judith Curry

On the time scale of a few decades ahead, regional variations in weather patterns and climate will be strongly influenced by natural internal variability. The potential applications of high resolution decadal climate change predictions are described in this CLIVAR doc.  Based upon my own interaction with decision makers, I see a need on these time scales that is primarily associated with infrastructure decisions.  Sectors that seem particularly interested in predictions on this time timescale are city and regional planners, the military, and the financial sector.

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Posted in Attribution, climate models, Uncertainty

Climate model verification and validation: Part II

Posted on December 18, 2010 | 217 Comments

I’m starting a new thread for this topic, since interest in the previous thread has re-generated owing to this AGU abstract by Steve Easterbrook, entitled Do Over or Make Do?  Climate Models as a Software Development Challenge.

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Posted in climate models

Confidence in radiative transfer models

Posted on December 5, 2010 | 1,207 Comments

by Judith Curry

The calculation of atmospheric radiative fluxes is central to any argument related to the atmospheric greenhouse/Tyndall gas effect.  Atmospheric radiative transfer models rank among the most robust components of climate model, in terms of having a rigorous theoretical foundation and extensive experimental validation both in the laboratory and from field measurements.   However, I have not found much in the way of actually explaining how atmospheric radiative transfer models work and why we should have confidence in them (at the level of technical blogospheric discourse).  In this post, I lay out some of the topics that I think need to be addressed  in such an explanation regarding infrared radiative transfer.  Given my limited time this week, I mainly frame the problem here and provide some information to start a dialogue on this topic, I hope that other experts participating can fill in (and I will update the main post).

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Posted in climate models, Greenhouse effect

Climate model verification and validation

Posted on December 1, 2010 | 256 Comments

by Judith Curry

On the thread building confidence in climate models , a small amount of text was devoted to verification and validation (V&V).  In raising the level of the game, I included the following bullet:

• Fully documented verification and validation of climate models

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Posted in climate models

Water vapor mischief

Posted on October 23, 2010 | 199 Comments

There is a provocative new paper available at an online discussion journal:

Makarieva, Gorshkov, Sheil, Nobre, Li:  Where do winds come from?  A new theory on how water vapor condensation influences atmospheric pressure and dynamics. link

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Posted in climate models