Code to download ERA5 meteorological data from ECMWF that will suitable for converting to ARL format for ingestion into HYSPLIT. The downloaded grib files will be suitable for use with the era52arl program available with the HYSPLIT distribution. The era52arl program will be updated in the HYPSLIT repository as soon as the government shutdown ends.

hysplit_metdata_cds uses cdsapi module from Copernicus Data Service. ERA5 will soon only be available through the cdsapi. If you are using ecmwf-api see below.

There may be a problem with the velocity fields on the pressure levels. See: https://confluence.ecmwf.int/pages/viewpage.action?pageId=127305868

PYTHON 3.x Written to run on linux operating system

This python program aids in retrieving meteorological variables from the ERA5 dataset which HYSPLIT needs. grib files can be input into the era52arl fortran utility program (provided with the HYSPLIT distrubtion) to create a meteorological file that can be used as input into HYSPLIT.

for command line options run with --help
The program will write a file called new_era52arl.cfg. This file can be used as an input into the era52arl conversion program. It should be renamed era52arl.cfg to be read automatically by the program.

This script requires the cdsapi to be available to your PYTHONPATH. The best way is to install it via pip and the provided requirements.txt file. This should install all necessary requirements at once. just execute the following on your command line.

cd hysplit_metadata
pip install -r requirements.txt

The CDS API will not work out of the box. Instead it requires an access token which has to be requested from the CDS. The way how to receive the access token is described at https://cds.climate.copernicus.eu/api-how-to.

For instructions on creating an ecmwf account and retrieving a key see
[https://software.ecmwf.int/wiki/display/WEBAPI/Accessing+ECMWF+data+servers+in+batch]

The api key must be stored in the $HOME/.ecmwfapirc file.
The api key can be found at [https://api.ecmwf.int/v1/key/]

You may also download the tar file from the webpage and place the ecmwfapi directory so that is in your PYTHONPATH or it can also be a subdirectory of the directory where get_era5.py is located.

If you have conda you can also install by conda install -c conda-forge ecmwf-api-client