Climate Variability Diagnostics Package for Large Ensembles (CVDP-LE)

The Climate Variability Diagnostics Package for Large Ensembles (CVDP-LE) developed by NCAR's Climate Analysis Section is an automated analysis tool and data repository for exploring internal and forced contributions to climate variability and change in coupled model “initial-condition” Large Ensembles and observations.

The package computes a wide range of modes of interannual-to-multidecadal variability in the atmosphere, ocean and cryosphere, as well as long-term trends and key indices of global and regional climate. Diagnostics include the ensemble-mean (i.e., forced response) and ensemble-spread (i.e., internal variability) of each model, as well as quantitative metrics comparing the models to observations. All diagnostics and metrics are saved to a data repository for later use and analysis.

The CVDP-LE User’s Guide provides general background on initial-condition Large Ensembles, detailed documentation of all diagnostics and metrics in the package, and guidance on interpreting the results. Instructions for downloading and running the CVDP-LE are provided on the Code page and readme file, respectively.

The CVDP-LE can be applied to any suite of observational data, model simulations and time periods specified by the user. A few examples of CVDP-LE applications to the CESM2 Large Ensemble, the Multi-Model Large Ensemble Archive and the CMIP6 archive are linked below; additional comparisons including netCDF files of CVDP-LE calculations can be found in the Data Repository.

• CESM1/2 Large Ensembles 1920-2100
• MMLEA 1950-2018
• MMLEA 2019-2099
• CMIP6 Historical/SSP585 1900-2100

When presenting results from the CVDP-LE in either oral or written form, please cite:

Phillips, A. S., C. Deser, J Fasullo, D. P. Schneider and I. R. Simpson, 2020: Assessing Climate Variability and Change in Model Large Ensembles: A User’s Guide to the “Climate Variability Diagnostics Package for Large Ensembles”, doi:10.5065/h7c7-f961

We welcome your feedback and suggestions on any aspect of the CVDP-LE.

CVDP collaborators: Adam Phillips (software lead), Clara Deser (science lead), John Fasullo, Isla Simpson, and Dave Schneider, as well as other members of NCAR's Climate Analysis Section.