CMIP5 - Coupled Model Intercomparison Project Phase 5 - Overview
CMIP is a standard experimental protocol for studying the output of coupled ocean-atmosphere general circulation models (GCMs). It provides a community-based infrastructure in support of climate model diagnosis, validation, intercomparison, documentation and data access.
The purpose of these experiments is to address outstanding scientific questions that arose as part of the IPCC AR4 (the Intergovernmental Panel on Climate Change 4th Assessment Report) process, improve understanding of climate, and to provide estimates of future climate change that will be useful to those considering its possible consequences. (The IPCC’s AR5 is now scheduled to be published in early 2013).
CMIP5 is meant to provide a framework for coordinated climate change experiments for the next five years and thus includes simulations for assessment in the AR5 as well as others that extend beyond the AR5. CMIP5 is not, however, meant to be comprehensive; it cannot possibly include all the different model intercomparison activities that might be of value, and it is expected that various groups and interested parties will develop additional experiments that might build on and augment the experiments described here.
CMIP5 promotes a standard set of model simulations in order to:
- evaluate how realistic the models are in simulating the recent past,
- provide projections of future climate change on two time scales, near term (out to about 2035) and long term (out to 2100 and beyond), and
- understand some of the factors responsible for differences in model projections, including quantifying some key feedbacks such as those involving clouds and the carbon cycle
The CMIP5 (CMIP Phase 5) experiment design has been finalized with the following suites of experiments:
I "near-term" (decadal) hindcast/prediction simulations
II "long-term" simulations
III "atmosphere-only" (prescribed SST) simulations.