Control run for the HadCM3 model

The Hadley Centre Coupled Model Version 3 was developed from the earlier HadCM2 model. Various improvements were applied to the 19 level atmosphere model and the 20 level ocean model and as a result the model requires no artificial flux adjustments to prevent excessive climate drift. The atmosphere and ocean exchange information once per day, heat and water fluxes being conserved exactly. Momentum fluxes are interpolated between atmosphere and ocean grids so are not conserved precisely, but this non-conservation is not thought to have a significant effect. The main differences from the previous HadCM2 model are a significantly more sophisticated radiation scheme; the inclusion of the direct impact of convection on momentum; and the inclusion of a new land surface scheme that includes a better representation of evaporation, freezing and melting of soil moisture. The HadCM3 model was used by the Hadley Centre to provide input for the IPCC Third Assessment Report. The Control Run simulation contained in this dataset was used to initialise transient coupled HadCM3 simulations using a variety of emission scenarios. It uses fixed forcing representative of late nineteenth century atmospheric conditions. The control run was initialised and spun up as defined in Johns et al. (2003).