5.6.2. Namelist NAM_PREP_ISBA_SNOW

This namelist defines the type of snow scheme used in ISBA scheme.

• CSNOW : type of snow scheme. Possible snow schemes are:
  1. 'D95' : Douville et al (1995) snow scheme.
  2. '3-L' : Boone and Etchevers (2001); Decharme et al. (2016) N-layer (default 12) snow scheme
  3. 'EBA' : Bogatchev and Bazile (2005), Arpege operational snow scheme.
  4. 'CRO' : Crocus model
• NSNOW_LAYER : number of snow layers
• CFILE_SNOW : name of the file used to define the snow profiles. The use of a file or prescribed value of XRSNOW, XTSNOW, XWSNOW and XASNOW (and XSG1SNOW, XSG2SNOW, XHISTSNOW and XAGESNOW in case of CSNOW = CROCUS) has priority on the data in CFILE_SNOW file
• CTYPE_SNOW : type of the CFILE_SNOW file, if the latter is provided. CTYPE_SNOW must then be given. The following values are currently usable:
  • "MESONH" : the file type is a MESONH file.
  • "GRIB " : the file type is a GRIB file, coming from any of these models:
    1. "ECMWF " : european center forecast model
    2. "ARPEGE" : Arpege french forecast model
    3. "ALADIN" : Aladin french forecast local model
    4. "MOCAGE" : Mocage french research chemistry model
  • "LFI " : LFI PREP file
  • "ASCII": ASCII PREP FILE
• CFILEPGD_SNOW : name of the associated PGD file if CFILE_SNOW is a PREP files.
• CTYPEPGD_SNOW : type of the CFILEPGD_SNOW file, if the latter is provided. CTYPEPGD_SNOW must then be given. The following values are currently usable:
  • "MESONH" : the file type is a MESONH file.
  • "LFI " : LFI PREP file
  • "ASCII": ASCII PREP FILE
• LSNOW_IDEAL : if LSNOW_IDEAL = .FALSE. , only one value can be given for following snow parameters and a vertical interpolation is processed. If LSNOW_IDEAL = .TRUE., values are given for each layer and there is no vertical interpolation performed.
• LSNOW_FRAC_TOT : if LSNOW_FRAC_TOT = .TRUE., the total snow fraction XPSN = MIN(1.0, ZSNOWSWE(:)/XWCRN_EXPL) where ZSNOWSWE is the snow liquid water content, and XWCRN_EXPL is the critical value of the equivalent water content of the snow reservoir.
• LSNOW_PREP_PERM : activates or disactivates initialization over permanent ice areas.
• XWSNOW : uniform value to initialize snow content, one for each layer
• XZSNOW : depth of snow layers (m). Alternative to XWSNOW.
• XTSNOW : uniform value to initialize snow temperature, one for each layer
• XLWCSNOW: snow liquid water content (kg/m3)
• XRSNOW : uniform value to initialize snow density, one for each layer
• XASNOW : uniform value to initialize snow albedo
• XSG1SNOW : uniform value to initialize snow layers grain feature 1 for Crocus, one for each layer
• XSG2SNOW : uniform value to initialize snow layers grain feature 2 for Crocus, one for each layer
• XHISTSNOW : uniform value to initialize snow layer grain historical parameter for Crocus, one for each layer
• XAGESNOW : uniform value to initialize snow grain age for Crocus, one for each layer
• LSWEMAX : logical switch to set an upper limit on initial snow water equivalent
• XSWEMAX: upper limit of initial snow water equivalent