The Climate-system Historical Forecast Project (CHFP)
The WCRP Joint Scientific Committee (JSC) established a limited term (2005-2007) Task Force on Seasonal Prediction (TFSP) that drew upon expertise from all the WCRP core projects (CLIVAR, GEWEX, CliC and SPARC), the WCRP Working Group on Numerical Experimentation (WGNE) and the WCRP/CLIVAR Working Group on Coupled Modelling. Since June 2007, the mandate of the TFSP has now been assigned by the JSC to the CLIVAR Working Group on Seasonal to Interannual Prediction (WGSIP).
The TFSP proposed the CHFP as a multi-model and multi-institutional experimental framework for sub-seasonal to decadal complete physical climate system prediction. By the complete physical climate system, we mean contributions from the atmosphere, oceans, land surface cryosphere and atmospheric composition in producing regional and sub-seasonal to decadal climate anomalies. This experimental framework is based on advances in climate research during the past decade, which have lead to the understanding that modeling and predicting a given climate anomaly over any region is incomplete without a proper treatment of the effects of SST, sea ice, snow cover, soil wetness, vegetation, stratospheric processes, and atmospheric composition (carbon dioxide, ozone, etc.).
The observed current climate changes are a combination of anthropogenic influences and natural variability. In addition to possible anthropogenic influence on climate due to changing the atmospheric composition, it is quite likely that land use in the tropics will undergo extensive changes, which will lead to significant changes in the biophysical properties of the land surface, which in turn will impact atmospheric variability on sub-seasonal to decadal time scales. It is therefore essential that the past research by two somewhat non-interacting communities (i.e., climate change and seasonal prediction) be merged into a focused effort to understand the predictability of the complete climate system.
Download the CHFP proposal outline here.
The results of these experiments provide a framework for future experiments, specifically these prediction results will:
(i) Provide a baseline assessment of our seasonal prediction capabilities using the best available models of the climate system and data for initialisation.
(ii) Provide a framework for assessing of current and planned observing systems, and a test bed for integrating process studies and field campaigns into model improvements
(iii) Provide an experimental framework for focused research on how various components of the climate system interact and affect one another
(iv) Provide a test bed for evaluating IPCC class models in seasonal prediction mode.
Certain elements of the proposed experiment are already part of various WCRP activities. The intent here is to leverage these ongoing activities and to coordinate and synthesize these activities into a focused seasonal prediction experiment that incorporates all elements of the climate system. These experiments are the first necessary steps in developing seamless weekly-to-decadal prediction of the complete climate system.
The CHFP was launched at the WCRP Workshop on Seasonal Prediction, held in June 2007, Barcelona Spain.
B. Kirtman and A. Pirani, 2009: The State of the Art of Seasonal Prediction Outcomes and Recommendations from the First World Climate Research Program (WCRP) Workshop on Seasonal Prediction, BAMS, DOI: 10.1175/2008BAMS2707.1