6. One paragraph description of your model (e.g. abstract from report or paper);

Simulations for an alpine region using three snow schemes of varying complexity coupled to the Interactions between Soil, Biosphere, and Atmosphere (ISBA) soil-vegetation-atmosphere transfer scheme are compared. The ISBA baseline snow scheme is the least complex of the three snow models in that the snow pack is characterized by a single soil/snow composite layer. The most complex scheme (CROCUS) is a detailed multi-layer internal snow process model which is used for avalanche prediction by the French weather service. The intermediate complexity scheme is represented by a new three-layer snow model option. It has been introduced into ISBA in an effort to better understand which snow processes are the most important for atmospheric and macroscale hydrological applications. Compared to the simple baseline ISBA snow scheme, the explicit multi-layered approach resolves the large temperature gradients which can exist in the snow pack, distinguishes the thermal properties between the snow and the composite soil-vegetation layer, includes the effects of liquid water storage refreezing in the snow pack, and models the absorption of incident radiation within the pack.

50. Please provide references relevant to the model description and use.

    - currently preparing a manuscript for submission which
      documents the new model, shows validation results for
      micro-met sites in French Alps, intercompares these results
      with ISBA-FR and ISBA-CROCUS (CIRSE), then intercompares
      results of all 3 schemes coupled to macroscale hydrologic model
      (can send official reference once it has successfully completed
       peer review): It will be submitted by the end of Sept., 1999

      "An inter-comparison of three snow schemes of varying complexity
       coupled to the same land-surface and macroscale hydrological models"
       by A. Boone and P. Etchevers

    - currently an informal Post Script doc is available with model
      details