Toward an Earth system model: Atmospheric chemistry, coupling, and petascale computing

Atmospheric chemicals and aerosols are interactive components of the Earth system, with implications for climate. As part of the SciDAC climate consortium of labs we have implemented a flexible state-of-the-art atmospheric chemistry and aerosol capability into the Community Climate System Model (CCSM). We have also developed a fast chemistry mechanism that agrees well with observations and is computationally more efficient than our more complex chemistry mechanisms. We are working with other colleagues to couple this capability with the biospheric and aerosol-cloud interaction capabilities that are being developed for the CCSM model to create an Earth system model. However, to realise the potential of this Earth system model will require a move from terascale to petascale computing, and the greatest benefit will come from well balanced computers and a balance between capability and capacity computing.