Reading dataΒΆ

After downloading the data for ERA Interim or ERA5 via eraint_download resp. era5_download, images can be read with the ERA5GrbDs and ERA5NcDs (for grib and netcdf image stacks), respectively the ERA5GrbImg and ERA5NcImg (for single grib and netcdf images) classes. The respective functions for reading images are defined in ecmwf_models.erainterim.interface ecmwf_models.era5.interface.

The following examples are shown for ERA5 data, but work the same way with the respective ERA Interim functions.

For example, you can read the image for a single variable at a specific date. In this case for a stack of downloaded image files:

# Script to load a stack of downloaded netcdf images
# and read a variable for a single date.
from ecmwf_models.era5.interface import ERA5NcDs
root_path = "/path/to/netcdf_storage"
ds = ERA5NcDs(root_path, parameter='swvl1')
data = ds.read(datetime(2010, 1, 1, 0))

# Script to load a stack of downloaded grib images
# and read a variable for a single date.
from ecmwf_models.era5.interface import ERA5GrbDs
root_path = "/path/to/grib_storage"
ds = ERA5GrbDs(root_path, parameter='swvl1')
data = ds.read(datetime(2010, 1, 1, 0))

You can also read multiple variables at a specific date by passing a list of parameters. In this case for a set of netcdf files:

# Script to load a stack of downloaded netcdf images
# and read two variables for a single date.
from ecmwf_models.era5.interface import ERA5NcDs
root_path = "/path/to/storage"
ds = ERA5NcDs(root_path, parameter=['swvl1', 'swvl2'])
data = ds.read(datetime(2000, 1, 1, 0))

All images between two given dates can be read using the iter_images methods of all the image stack reader classes.