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[Hatef Monajemi <monajemi@xxxxxxxxxxxx>]

************** EFMH Spring 2011 Seminar Series ************** 

Date: Monday, April 4, 2011 
Time: 12pm-1:15pm 
Location: Y2E2 101 

Guest speaker: Dr. Craig Bishop 
Naval Research Laboratory-Monterey, California 

Abstract: 

Multi-model ensembles are important tools in understanding uncertainties in climate projection. By using different models and simulations, we aim to create a set of independent estimates of a climate prediction problem, and so hope to better quantify prediction uncertainty. Yet we know that research groups share literature, data and even model code to what extent do different models represent independent estimates? What is the relationship between model performance and model independence? Here, we suggest that error correlation provides a natural empirical definition for model dependence and provide a weighting strategy to account for dependence when using the multi-model mean. These weights recognize the contribution of each simulation to the overall predictive ability of the ensemble and so can be used for ensembles with varying numbers of simulations from different models. Furthermore, we show that the expected level of error correlation between independent estimates depen
  
ds on assumptions about the relationship between the ensemble and observations. It is commonly implicitly assumed, for example, that the climate system is deterministic. We present an alternative interpretation, the replicate Earth paradigm, that explicitly permits chaotic climate behavior in a model evaluation context. We illustrate a technique that transforms an existing ensemble to provide independent estimates within the replicate Earth paradigm, enabling a clearer relationship between the frequency of particular modelled events and the likelihood of their actual occurrence. 

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Below is a link to the sign up sheet for individual meetings with our speaker. There is a link in the document that guides you to the details o f the talk given by Dr. Craig Bishop on April 4th. Please sign up to meet with Dr. Bishop i f you are interested. 

https://docs.google.com/document/d/1OV9Bgih8Uercqewg-G70CaawQBWwM4PawN-iSKii6aE/edit?hl=en&authkey=CIPgo5QL 



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Yusong Rogers 
> Administrative Associate 
> 
> Environmental Fluid Mechanics & Hydrology Program 
> Department of Civil & Environmental Engineering 
> Stanford University 
> 
> Y2E2, Room 126 
> m/c 4020 
> 473 Via Ortega 
> Stanford, CA 94305 
> 
> Tel: 650 723-4372 
> Fax: 650 725-9720 



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