An efficient numerical terrestrial scheme (ENTS) for fast earth system modelling

TitleAn efficient numerical terrestrial scheme (ENTS) for fast earth system modelling
Publication TypeTyndall Working Paper
SeriesTyndall Centre Working Papers
Tyndall Consortium Institution


Secondary TitleTyndall Centre Working Paper 83
Keywordscarbon cycle, Earth system, efficient numerical terrestrial scheme, ENTS, fast earth system modelling, land surface, Model, photosynthesis, respiration, soil, vegetation
AuthorsWilliamson, M., T. Lenton, J. Shepherd, and N. Edwards
Year of Publication2006

Here we present a new land surface physics and terrestrial carbon cycle model, called the Efficient Numerical Terrestrial Scheme (ENTS). The model is designed for long time period simulations and large ensemble studies in Earth system models of intermediate complexity (EMICs). ENTS contains reservoirs of vegetation carbon, soil carbon and soil water in each grid cell. It is designed as a spatial model of minimal complexity and process description needed to simulate the coupled biophysical land state. We have developed new simple parameterisations of vegetation fractional cover and roughness length as functions of vegetation carbon. We also make and justify the approximation that the land radiation balance comes to equilibrium with the atmosphere quickly (in a few days) when the solar forcing is a diurnal average (as in our EMIC). We tune the carbon cycle parameters towards observed values of global carbon storage in vegetation and soil and estimated global fluxes of net photosynthesis, vegetation respiration, leaf litter and soil respiration. When the model is forced with long term monthly mean fields of NCEP reanalysis climate data, we find ENTS yields broadly accurate patterns of vegetation and soil carbon storage, vegetation fraction, surface albedo, land temperature and evaporation.