Create a snow cover and snow depth analysis on a nam or global gfs gaussian grid using nesdis/ims snow cover, autosnow snow cover and/or afwa depth data.
The ims snow cover product is now produced by the national ice center, not nesdis. however, in this code, references to ims still use the "nesdis" identifier.
input files, to define model grid, and for runtime configuration:
- fort.41 configuration namelist
- latitudes on model grid (grib 1 or grib 2)
- longitudes on model grid (grib 1 or grib 2)
- model land/sea mask (grib 1 or grib 2)
- gfs definition of reduced grid (ascii, optional)
input snow data files; see remarks section on how to select.
- nesdis/ims nh 4km (96 mesh) snow cover data (grib1 or grib 2)
- nesdis/ims nh 23km (16 mesh) snow cover data (grib1 or grib 2)
- nesdis/ims nh 23km land mask (ascii, required when using 23km ims)
- afwa nh/sh 8th mesh (46km) snow depth data (binary)
- afwa nh/sh 8th mesh land/sea mask (binary, required when using 8th mesh nh/sh afwa data)
- afwa nh/sh 16th mesh (23km) snow depth data (grib 1)
- autosnow sh snow cover data (grib 2)
- nesdis/ims weekly nh snow cover climatology (grib 2) (used to qc input snow data).
output files:
- snow cover and depth on the model grid (grib1 or grib2)
exit states (non-zero condition is fatal):
- 0 - successful run
- 40 - bad open of file when checking its file type (routine grib_check).
- 41 - ims file not grib1 or grib2 format
- 47 - error in grib2_check. unknown grid type.
- 48 - error creating model output grib2 file
- 49 - bad open of model output grib2 file
- 50 - error converting to grib2 grid description template
- 53 - bad nesdis/ims data.
- 54 - bad input snow data selection
- 55 - error in iplib interpolation routine
- 57 - bad write of model snow depth data to grib1 file
- 58 - bad write of model snow cover data to grib1 file
- 59 - bad open of model output grib1 file
- 60 - bad open afwa snow data
- 61 - bad read afwa snow data
- 62 - bad open afwa land mask
- 63 - bad read afwa land mask
- 70 - bad degrib of nesdis/ims snow cover data
- 71 - bad degrib of nesdis/ims sea ice data
- 72 - bad degrib of nesdis/ims data header
- 73 - bad open of nesdis/ims data
- 74 - bad open of autosnow data
- 75 - bad degrib of autosnow data
- 76 - problem with gfs 'lonsperlat' file
- 77 - bad open on configuration namelist
- 78 - bad read on configuration namelist
- 79 - unrecognized model grid type
- 80 - bad open on model latitude grib file
- 81 - bad read on model latitude grib header
- 82 - bad degrib of model latitude data
- 83 - bad open on model longitude file
- 84 - bad degrib of model longitude data
- 85 - bad open of model land mask file
- 86 - bad degrib of model land mask data
- 87 - bad open of nesdis/ims land mask file
- 88 - bad read of nesdis/ims land mask data
- 90 - model latitude file not grib1 or grib2
- 91 - model longitude file not grib1 or grib2
- 92 - model land mask file not grib1 or grib2
The determination of cover and depth on the model grid depends on the input snow data selected:
nam grids:
- nesdis/ims only - An analysis of snow cover on the model grid is produced. No depth analysis is produced.
- afwa only - An analysis of snow cover and depth on the model grid is produced. Depth is determined from the afwa data. Cover is set to 100% where afwa indicates snow and 0% otherwise.
- nesdis/ims and afwa - An analysis of snow cover and depth on the model grid is produced. Cover is determined by the nesdis/ims data. If cover is greater than user-defined threshold (variable snow_cvr_threshold) the depth is set to the afwa value or a nominal value, whichever is greater. The nominal value is user-defined (varaible min_snow_depth). If cover is less than user- defined threshold, the depth is set to 0, regardless of the afwa depth value.
gfs grid:
- nesdis/ims and autosnow only - An analysis of snow cover and depth on the model grid is produced. Cover is determined from the ims and autosnow data. If cover is greater than the user-defined threshold (variable snow_cvr_threshold), the the depth is set to the user-defined default depth (variable min_snow_depth).
- afwa only - An analysis of snow cover and depth on the model grid is produced. Depth is determined from the afwa data. Cover is set to 100% where afwa indicates snow and 0% otherwise.
- nesdis/ims, autosnow and afwa - An analysis of snow cover and depth on the model grid is produced. Cover is determined by the ims and autosnow data. If cover is greater than user-defined threshold (variable snow_cvr_threshold) the depth is set to the afwa value or a nominal value, whichever is greater. The nominal value is user-defined (varaible min_snow_depth). If cover is less than user- defined threshold, the depth is set to 0, regardless of the afwa depth value.
Program History Log
- 2005-dec-16 gayno initial version
- 2007-nov-30 gayno added processing of nam b-grids. improved thinning for gfs grids.
- 2008-feb-01 gayno added option to use autosnow data in southern hemisphere.
- 2014-feb-14 gayno read grib 1 or grib2 version of nesdis/ims data
- 2014-sep-30 gayno read grib 1 or grib2 version of model lat, lon and mask files. convert nh weekly snow climatology to grib 2. option to output model depth and cover analysis in grib2.
- Returns
- 0 for success, error code otherwise.
- Author
- gayno
- Date
- 2005-dec-16
Definition at line 144 of file driver.F90.
References snow2mdl::interp(), model_grid::model_grid_cleanup(), program_setup::read_config_nml(), model_grid::read_mdl_grid_info(), snowdat::readafwa(), snowdat::readautosnow(), and snowdat::readnesdis().
1.8.5 
