Scripts for retrieving and processing NOHRSC SNODAS daily binary files.
Includes a number of scripts in bash, NCL, R, and/or matlab.
This is a work in progress started in July 2017, so keep posted for additional scripts & edits.
Codes will require customization and will not run as is.
I'm happy to answer questions and welcome helpful suggestions for improving efficiency of any code:
[email protected]
Files listed in order of use in my processing & analysis:
getSNODAS.sh
- a short bash script for retrieving Nov-Apr (2004-2017) .tar files from the National Snow and Ice Data Center (NSIDC) ftp site. Uses wget.
untarSNODAS.sh
- bash script that untars and unzips SNODAS files.
- moves all .Hdr files to a separate directory. I do this because the gdal_translate command usually spits out errors if the .Hdr file is in the same directory as the .dat files. I haven't found a need for them yet.
- moves all .dat files into separate subdirectories by variable.
procSNODAS.sh
- bash script that converts .dat files to .nc using gdal_translate. Also uses nco's ncrename and ncatted.
addtimeSNODAS.ncl
- adds unlimited time dimension to .nc files created in procSNODAS.sh. Surely there's a way to do it with NCO, but I found it to be easier in NCL.
subsetSNODAS_avgSNWZ.ncl
- selects a regional subset from SNODAS files, calculates a seasonal (or monthly) mean, max, and min snow depth for each season,and then calculates a climatological (well, 2004-2017) mean, max, and min for the period of record.
- output is a single .nc file of the climatological mean, max, and min snow depth for regional subset.
- could combine with plotting script (plotNESNODAS.ncl) if region is small.
plotNESNODAS.ncl
- plots up map of seasonal or monthly average snow depth for region in US. Output is .png graphic of data.
subsetSNODAS_avgSNWDAYS.ncl
- similar to subsetSNODAS_avgSNWZ.ncl, this script selects a regional subset from SNODAS files, calculates the number of
days per winter (Nov-Apr) with snow depth > user-defined threshold for each year in record (2004-2017), and then calculates the climatological mean number of snow days > user-defined snow depth threshold. - output is a single .nc file of climatological mean number of snow days with snow depth > user-defined snow depth
- could combine with plotting script (plotNESNODAS_snowdays.ncl) if region is small.
plotNESNODAS_snowdays.ncl
- plots up map of number of days per winter with snow depth > user-defined threshold. Includes contour at 20 days.
- Output is .png graphic of data.