Currently, even sophisticated regional climate models (RCMs) are limited in the spatial detail they can resolve. The significance of the simulated spatial details depends to some extent on the resolution of the specified surface fields the model needs to infer surface parameters. There are fixed values that are known quite accurately, such as the planetary data (the earth's radius and its angular velocity of rotation, the acceleration of gravity, etc.), but the spatially-varying data used to specify boundary conditions such as surface topography, surface roughness, surface albedo, soil moisture, heat capacity, etc., need to be used with caution.

A significant amount of the spatial variability of climate in the model is generated at the surface. The procedure used for the treatment of subgrid-scale boundary layer and surface processes are collected in the model's physical parameterisation module. The boundary-layer and land-surface schemes that use these parameterisations need, in addition to the resolved variables, a number of parameter fields such as the local proportion of vegetation and bare ground that are used to derived surface boundary conditions. The boundary turbulent fluxes of sensible heat and evapotranspiration are important for the maintenance of the energy and water balance at the surface. Solar radiation is the main source of energy available for the climate system and the reflection at the surface depends on the surface albedo. Outgoing infrared terrestrial radiation is a function of the ground surface temperature which in turn is related to the amount of energy absorbed by the ground. All these fluxes thus depend on the surface characteristics and its state that need to be accurately determined since they have a profound effect on the lower atmosphere, on the atmospheric circulation, and ultimately on climate.

Land-cover features are in close interaction with climate at the surface. There is both a significant latitudinal and altitudinal dependence of landcover types. Mountain glaciers are found in highland regions at all latitudes, and represent only a very small fraction of the global cryosphere; thus mountain glaciers tend to influence climate at the regional scale. Their surface characteristic generate particular local weather and climatic conditions (Van Den Broeke, 1997) that also affect surrounding regions. These conditions are induced by the surface temperature of a glacier which is below freezing, by the reflection of a large amount of the incoming solar energy, and by the fact that they retain most of the snowfall during much of the year (Chap. 4; Paterson 1995). In Switzerland, glaciers covering close to 1500 km2, represents about 3% of the total area of the country.

As a first approach, prescribing fixed lower boundary conditions for glaciers is valid because the time scale for change in extent of these ice masses are much longer than the current integration time of the model.

This paper describe the results obtained from numerical simulations performed with the Canadian Regional Climate Model (CRCM) to assess the sensitivity of the simulated surface variables and turbulent fluxes when glaciers are included as part of the surface boundary conditions in the Swiss Alps. Section 2.1 describes the CRCM, section 2.2 section briefly reviews the concepts that form the basis for the parameterisation of the surface processes over land in CRCM and its relation with the surface characteristics it employs, section 2.3 discusses experimental setup and the procedure used to define the lower boundary conditions in the experiments, section 3 analyses the results, and concluding remarks to this work are included in section 4.

Getting Started With Solar

Getting Started With Solar

Do we really want the one thing that gives us its resources unconditionally to suffer even more than it is suffering now? Nature, is a part of our being from the earliest human days. We respect Nature and it gives us its bounty, but in the recent past greedy money hungry corporations have made us all so destructive, so wasteful.

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