1. Please write down the name (and abbreviation) of your snow model or land-surface model with snow component?
MAR Snow Model
2. Name and address of model developer;
Dr. Ir. Hubert Gallee Institut de Recherches pour le Developpement Laboratoire d'etude des Transferts en Hydrologie et Environnement BP 53 F-38041 GRENOBLE Cedex 9 FRANCE Teleph: 33 (0) 476 827 061 TeleFX: 33 (0) 476 825 286 e-mail: Hubert.Gallee@hmg.inpg.fr URL: http://www.astr.ucl.ac.be/astr/fr/recherche/mesoechelle
3. Name and address of model user;
As above +
4. Please indicate whether your model is developed for application:
5. The first year when the model was used;
6. One paragraph description of your model (e.g. abstract from report or paper);
The snow model is a multi-layered one-demensional thermodynamic model. The number of layers is variable and depends on the snow evolution. For each layer, the temperature , density, water content and thickness are calculated. The calculation of the optical properties, albedo and penetration of solar radiation, is based on the CROCUS snow metamorphism laws. Melting, percolation, refreezing and settling are taken into account. The model also includes a snow drift model. Snow erosion threshold depends on snow surface properties such as density, dendricity, sphericity and particles size. The model can be used for seasonal and polar snow packs.
7. Please specify any known application range or restrictions;
The model can be used off-line (forced by atmospheric variables) or coupled to an atmospheric model.
8. What are the development data needs;
9. What are the operational data needs?
10.Please indicate with an "x" for those meteorological variables used to DRIVE your snow model?
11. List the state variables (e.g., snow temperature, snow water equivalent, etc) your snow model uses?
Temperature, density, liquid water content and thickness of each snow layer
12. List the measurable/adjustable parameters (e.g., snow surface aerodynamic roughness, maximum albedo at visible wavelength, etc, excluding initial conditions) your snow model uses?
snow surface aerodynamic roughness, slope parameter
13. What are the output data?
14. What computer language does your model use?
15. How many subroutines (or functions) does your snow model have?
16. Number of lines of the snow code?
4898 (2382 effective lines)
17. What is the recommended hardware?
Any unix workstation (model has been used so far on DEC and HP workstations)
18. How does your model determine the form of precipitation (i.e., snowfall and rainfall)? Please give the formulation.
Based on air temperature or given as input data
19. Is your snow model one dimensional or multi-dimensional? Please specify.
20. If one dimensional, how many layers are there in your snow model? Please specify layering structure. varies.
The CROCUS snow metamorphism laws optimize the number of snow layers.
21. What is your snow model time step?
22. Does your model snow albedo allow its spectral differences
(visible vs. near-IR)? Yes
directional differences (direct vs. diffuse)? Yes
23. Is your model snow albedo a function of
24. Does your snow model explicitly treat liquid water retention and percolation within the snowpack?
25. Does your snow model account for changes in the hydraulic and thermal properties of snow due to meltwater refreezing?
26. Is snow density in your snow model changing with time or fixed?
Changing with time
27. Is heat capacity and conductivity in your snow model changing with time or fixed?
Changing with time
28. Does your snow model simulate vapor transfer in the snowpack?
No , "effective conduction" used
29. Does your snow model account for the heat transfer between the bottom of the snowpack and the underlying soil?
30. In snow energy balance, does your model consider heat convected by rain or falling snow?
31. Does your snow model include snow drifting and redistribution by wind (or avalanche)? If so, how?
32. How is areal snow distribution treated? N/A
33. Does your snow model account for sub-grid (or sub-watershed) effects of topography?
If so, how is temperature distributed?
how is precipitation (spatial, elevation and corrections) distributed?
how is solar radiation distributed?
how is wind distributed?
how are other meteorological variables distributed?
34. Does your snow model consider snow-vegetation interaction?
35. Does the snow-vegetation interaction account for different vegetation types (grass vs. forest), different vegetation heights (short vs. tall), different vegetation densities (small vs. large LAI), different vegetation coverages (sparse vs. dense vegetation)?
36. Are snow interception, drip and melt on canopy surface allowed in your model?
37. How is the upper limit of the canopy interception determined?
38. In the presence of vegetation, how is snow surface albedo altered?
39. In the presence of vegetation, how is snow surface roughness altered?
40. In the presence of forest, does your snow model allow spatial variability of snow depth and water equivalent on forest floor?
41 (a). How does your model deliver snowmelt to the soil system (e.g. affecting soil moisture)?
(b). Once snowmelt is generated, how does your model relate it to runoff?
Percolation until unpermeable ice or ground layer, then drained away.
42. How is frozen soil treated in your model?
43. Has your snow model been tested with the field data?
Is so, what data?
Centre d'etudes de Neige (Grenoble, France): Col de Porte site data
ETH (Zurich, Switserland): ETH-Camp (West Greenland), 1991 summer data
What are their temporal and spatial scales?
Winter and summer seasons, site data
44. Has your snow model been used together with remote sensing data as input?
If so, how?
45. If your snow model is coupled with a numerical weather forecasting model or climate model, has the model snow product been compared with satellite data?
If so, what satellite data were used?
46. Please list any other previous applications.
47. Please specify verification criteria, if any?
48. What are the model fitting procedures, if any?
49. What are future plans for using/improving the model?
50. Please provide references relevant to the model description and use.
Gallee, Hubert and Guy Schayes (1994). Development of a three-demensional Meso-gamma Primitive Equation Model: Katabatic Winds Simulation in the Area of Terra Nova Bay, Antarctica, Monthly Weather Review, 22, April 1994.
Gallee, Hubert and Peter Duynkerke (1997). Air-Snow Interactions and the Surface Energy and Mass Balance over the Melting Zone of West Greenland during GIMEX, J. Geophys. Res., 102, 13813-13824.
Gallee, Hubert (1998). A simulation of blowing snow over the Antarctic Ice Sheet, Ann. Glaciol., 28, 203-205.
Gallee, H., Guyomarc'H, G. and E. Brun (1999). Impact of the snow drift on the Antarctic Ice Sheet surface mass balance: a sensitivity study to snow, Bound.-Layer Meteor., submitted.
Lefebre, F., Gallee H. and Van Ypersele J.P. (1999). Snow melting at ETH- Camp (West Greenland, 1155 m a.s.l.) during the summer of 1991: Sensitivity to different Albedo Parametrizations, Journal of Glaciology, submitted.