1. Please write down the name (and abbreviation) of your snow model or land-surface model with snow component?

Tohoku Snow Cover Model with One-layer (TSCM1)

2. Name and address of model developer;

  YAMAZAKI Takeshi
  Geophysical Institute,
  Tohoku University
  Aza-Aoba, Aramaki,
  Aoba-ku, Sendai, 980-8578, JAPAN
TEL +81-22-217-5781,  FAX +81-22-217-7758

3. Name and address of model user;

Same as Q2

4. Please indicate whether your model is developed for application

   in understanding snow processes,    X
   in a runoff forecasting model,      X 
   in a weather forecasting model,     X   
   in a global climate model (GCM),     
   or other (please specify)?          X
      (estimating energy exchange between the atmosphere and ground)

5. The first year when the model was used;


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

A snow-cover model based on a heat balance method has been developed. This model takes into account both the heat balance at the snow surface and that of the entire snow cover and simultaneously predicts the snow surface temperature and freezing depth. Observed or estimated incident radiation data are required for operation of the model.

7. Please specify any known application range or restrictions;

8. What are the development data needs;

9. What are the operational data needs?

incident solar and atmospheric radiation, air temperature, wind speed, specific humidity, preciptation

10. Please indicate with an "x" for those meteorological variables used to DRIVE your snow model?

   precipitation                   : X
   air temperature                 : X
   wind speed                      : X
   wind direction                  :   
   humidity                        : X 
   downwelling shortwave radiation : X
   downwelling longwave  radiation : X
   cloud cover                     :  
   surface pressure                :   

11. List the state variables (e.g., snow temperature, snow water equivalent, etc) your snow model uses?

snow surface temperature, freezing depth, snow water equevalent

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?

  bulk coefficients for sensible and latent heat,
  maximum water content,
  thermal conductivity,
  maximum and minimum albedo

13. What are the output data?

  sensible and latent heat fluxes,
  amount of snowmelt

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?


17. What is the recommended hardware?


18. How does your model determine the form of precipitation (i.e., snowfall and rainfall)? Please give the formulation.

threshold temperaure at 1 C

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.

One and surface heat balance

21. What is your snow model time step?

One hour

22. Does your model snow albedo allow its

    spectral differences    (visible vs. near-IR)?
    directional differences (direct  vs. diffuse)?

23. Is your model snow albedo a function of

      snow age                 X
      grain size                
      solar zenith angle         
      snow depth?               

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?


27. Is heat capacity and conductivity in your snow model changing with time or fixed?


28. Does your snow model simulate vapor transfer in the snowpack?


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?

33. Does your snow model account for sub-grid (or sub-watershed) effects of topography? If so, how is temperature distributed?

Yes. linear function of elevation

how is precipitation (spatial, elevation and corrections) distributed?

linear function of elevation

how is solar radiation distributed?


how is wind distributed?


how are other meteorological variables distributed?

34. Does your snow model consider snow-vegetation interaction?

No, however, it is possible to conect vegetation model

35. Does the snow-vegetation interaction account for

 different vegetation types     (grass vs. forest),             
 different vegetation heights   (short vs. tall),               X
 different vegetation densities (small vs. large LAI),          X
 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?

It depends on LAI and snow albedo

39. In the presence of vegetation, how is snow surface roughness altered?

Mainly, it depends vegetation density

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?


42. How is frozen soil treated in your model?

43. Has your snow model been tested with the field data?

If so, what data? (areas)

what are their temporal and spatial scales?

  routine data in Japan
  hourly, 20km x 20km

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.

estimating inflow to a dam

47. Please specify verification criteria, if any?

snow water equivalent, inflow to a dam

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.

Kondo J. and T. Yamazaki, 1990: A prediction model for snowmelt, snow surface temperature and freezing depth using a heat balance method. J. Appl. Meteor., 29, 375-384.

Yamazaki T. and J. Kondo, 1992: The snowmelt and heat balance in snow-covered forested areas. J. Appl. Meteor., 31, 1322-1327.

Yamazaki T., 1995: The influence of forests on atmoshperic heating during the snowmelt season. J. Appl. Meteor., 34, 511-519.

-- Last updated Fri Oct 8 12:47:54 MST 1999 by Zong-Liang Yang.
For questions and comments, please contact Zong-Liang Yang