Operation¶

Parameter files¶

Three parameter files are used to control GLOBSIM. There is one for each step in the procedure (download, interpolate, scale). The parameter files should all be in the /par subdirectory of the project directory.

Downloading¶

Keyword	Description
project_directory	This is the full path to the project directory which stores the downloaded files and the control files. It should include a subdirectory called /par which contains parameter files (control files) as well as a csv describing the sites to which data are scaled.
credentials_directory	The location of the credential files (e.g. .merrarc and .jrarc). Does not apply to credential file .ecmwfapi which defaults to your home directory. It is recommended to set this parameter to your home directory
chunk_size	How many days to include in each download file. Larger chunk size values mean that a smaller number of files will be downloaded, each with a larger size
bbN	Coordinates for northern boundary of bounding box describing the area for which data will be downloaded. Coordinates must be in decimal degrees.
bbS	Coordinates for southern boundary of bounding box describing the area for which data will be downloaded. Coordinates must be in decimal degrees.
bbW	Coordinates for western boundary of bounding box describing the area for which data will be downloaded. Coordinates must be in decimal degrees with negative values for locations west of 0.
bbE	Coordinates for eastern boundary of bounding box describing the area for which data will be downloaded. Coordinates must be in decimal degrees with negative values for locations west of 0.
ele_min	Minimum elevation that will be downloaded. Recommended to leave at 0.
ele_max	Maximum elevation that will be downloaded. Should be at least 2500.
beg	First date for which data is downloaded YYYY/MM/DD
end	Last date for which data is downloaded YYYY/MM/DD
variables	Which variables should be downloaded from the server. The variables names come from the CF Standard Names table. It is recommended that the variables parameter be left to include all relevant variables: air_temperature, relative_humidity, precipitation_amount, downwelling_longwave_flux_in_air, downwelling_longwave_flux_in_air_assuming_clear_sky, downwelling_shortwave_flux_in_air, downwelling_shortwave_flux_in_air_assuming_clear_sky, wind_from_direction, wind_speed

Note

To check download progress, you can use your credentials to log onto the website for JRA and ERA5 (CDS API)

Interpolating¶

Keyword	Description
project_directory	This is the full path to the project directory which stores the downloaded files and the control files. It should include a subdirectory called /par which contains parameter files (control files) as well as a csv describing the sites to which data are scaled.
station_list	The filename (without path) of csv containing site information such as sitelist.csv (note that this must match the scaling parameter file)
chunk_size	How many time-steps to interpolate at once. This helps memory management. Keep small for large area files and/or computers with little memory. Make larger to get performance improvements on computers with lots of memory.
beg	Beginning of date range for which data will be interpolated in YYYY/MM/DD format. Note that this date range must include dates that are represented in the downloaded data.
end	End of date range for which data will be interpolated in YYYY/MM/DD format. Note that this date range must include dates that are represented in the downloaded data.
variables	Which variables should be downloaded from the server. The variables names come from the CF Standard Names table. It is recommended that the variables parameter be left to include all relevant variables

Rescaling¶

Keyword	Description
project_directory	This is the full path to the project directory which stores the downloaded files and the control files. It should include a subdirectory called /par which contains parameter files (control files) as well as a csv describing the sites to which data are scaled.
station_list	The filename (without path) of csv containing site information such as sitelist.csv (note that this must match the interpolation parameter file)
output_file	Path to output netCDF to be created.
overwrite	Either True or False. Whether or not to overwrite the output_file if it exists.
time_step	The desired output time step in hours
kernels	Which processing kernels should be used. Missing or misspelled kernels will be ignored by globsim.

Station list for interpolation¶

This is an example of a Globsim station list file. The resulting netCDF file will use the station numbers as identifiers. Use extension like this: ‘my_stations.csv’:

station_number, station_name, longitude_dd, latitude_dd, elevation_m
1, yellowknife_airport, -114.44234, 62.46720, 207
2, ekati_airport, -110.60804, 64.70591, 461

Project directory¶

The project directory is the location to which data is downloaded and where processed data is found. The project directory is subdivided by re-analysis type and by the type of derived product:

project_a/              (project directory)
project_a/par/          (parameter files for data download and interpolation)
project_a/jra-55/       (JRA-55 data)
project_a/eraint/       (ERA-Interim data)
project_a/era5/         (ERA-5 data)
project_a/merra2/       (MERRA 2 data)
project_a/station/      (data interpolated to stations)
project_a/scale/        (final scaled files)