Application of the Canadian Land Surface Scheme to a full canopy crop during a drying cycle

The Canadian Land Surface Scheme (CLASS), a land surface parametrization scheme for use in large scale climate models, was assessed using the observed surface climate data from a full canopy crop in southern Ontario during a 10 day drying cycle period. Half-hourly and daily modelled radiation and energy balance components and other surface climate parameters,were compared to field observations. Different simulations using CLASS were employed and each contained different degrees of realism in model initialization. In general, CLASS simulations of radiation and energy balance components and surface climate parameters were good. Further, only modest improvements in model performance were achieved using more stringent initializations when compared to CLASS default specifications. It was also demonstrated that routine meteorological observations from an Atmospheric Environment Service network station could be used as meteorological input to CLASS without a loss in model output quality. From the research findings, it is apparent that full crop canopy conditions cart be successfully modelled and that the more complex aspects of seasonal crop development and the wider range in the surface control of physical climatology should now be addressed using the CLASS framework. However to ensure overall confidence in modelling approaches, the need to compare model results with quality field observations of surface climate processes remains important.