reanalysis_validation

Repository for downloading, processing and validating ERA5 reanalysis data against met station observations.

Use this code to download ERA5 data for a specified polygon from the CDS database, using the cdsapi and iris packages, and convert from grib to netCDF. Co-ordinates below the equator and/or west of the prime meridian are negative. The code can easily be adapted to download ERA-Interim or ERA5-Land data: just ensure the target variables and download path match those from the CDS database.

Order of processiong (files found in the ERA5_scripts folder):

• Ensure the full list of variables is correct in era5_variables.txt and define the target variables to be downloaded in era5_grib_variable_info.txt.
• Run the retrieve_era5_hourly.py script using the batch command located in batch_retrieve_and_process_data.sh.
• Process the data using process_era5_hourly_from_grib.py script using the batch command also located in the shell file.
• Additional processing options can be found in process_era5_6-hourly_from_grib.py.

Then extract the data at a single, specified point, related to the coordinates of the meteorological station using the Extract_data_at_point.ipynb Jupyter Notebook. Data will be interpolated to the exact point from the original coarse resolution. Download the meteorological station data separately and store in a csv file.

Finally, analyse the data either at station-level (Analyse_data_at_single_station.ipynb) or across all regions and stations (Analyse_data_all_stations.ipynb), and make plots.

Note that soil temperature data are treated separately as there are often large gaps in the soil temp data from met stations.

Retrieval and processing code correct as of Summer 2023. This code was used in the paper: https://doi.org/10.1002/joc.8456 .