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Large Ensemble Working Group

The US CLIVAR Working Group on  Large “Initial-Condition” Earth System Model Ensembles (LEs) was formed in March 2018. The intent of the working group is to spearhead a dedicated effort across the national and international climate communities to advance progress on identifying anthropogenic influences on weather and climate amidst the “noise” of internal variability. The timeliness and cross-cutting nature of the problem, together with promising new observational and modeling approaches, means this working group has an unprecedented opportunity to make substantive progress on this tractable issue.

The main objectives of the working group are:

  1. Foster exchange of ideas relevant to LEs across disciplines (i.e., atmosphere, ocean, land, biogeochemistry).
  2. Contribute a peer-reviewed article containing a statement of the problem and its importance, results from a comparison of existing LEs from five different models, a proposed design of an LE-MIP, and opportunities for further progress. 
  3. Lead the LE-MIP and dissemination of model output. 
  4. Design an “Observational-LE.” 


Large Ensemble Working Group
Clara Deser (co-chair) NCAR
Keith Rodgers (co-chair) IBS Center for Climate Physics, Pusan National University, South Korea
Toby Ault Cornell U.
Tom Delworth  NOAA GFDL
Pedro DiNezio  U. Texas-Austin
Arlene Fiore Columbia U.
Claude Frankignoul  U. Pierre et Marie Curie, France
John Fyfe CCMA, Canada
Dan Horton Northwestern U.
Jennifer Kay U. Colorado
Reto Knutti ETH, Switzerland
Flavio Lehner NCAR
Nikki Lovenduski U. Colorado
Jochem Marotzke MPI, Germany
Karen McKinnon U. California-Los Angeles
Shoshiro Minobe Hokkaido U., Japan
Jim Randerson  U. California-Irvine
James Screen U. Exeter
Isla Simpson  NCAR
Mingfang Ting  Columbia U.