Homepage Download location: Copernicus Marine Data Store
Download procedure: Copernicus Marine Toolbox
Downloads of Copernicus Marine Data Store are handled through the Copernicus Marine Toolbox. This is a python-oriented toolbox for accessing, subsetting, and downloading CMS data, either through the Command Line Interface or the Python API.
Install the toolbox in your local environment, following instructions here.
Follow the instructions on the main page to see the various uses of the toolbox. Defining a GLORYS subset
To determine the commands with which to download GLORYS data specifically, navigate to the download location above.
Navigate to the “Data Access Tab”
For the relevant dataset (e.g. “Daily”), click on “Form” button under “Subset” category to go to the data selection GUI (Copernicus sign-in required).
Select the required variables, region, and date range.
If the dataset is small enough and you want to download locally (i.e. to the computer in which you have launched the browser) you will be able to do so using the clickable icon in the upper right.
If the dataset is too large, or if you’re downloading directly to a remote machine, click on the “Automate” button on the upper right. This will open a pop up with both a “Command-Line Interface” and a “Python API” tab, with the exact commands that you need to use to download the data. Copy and paste these into a python script (locally if you want to download to your local computer, or on a remote machine), and run that script.
An example of the python approach to downloading daily GLORYS data for the North Atlantic is given below:
import copernicusmarine
copernicusmarine.subset(
dataset_id="cmems_mod_glo_phy_my_0.083deg_P1D-m",
variables=["mlotst"],
minimum_longitude=-100,
maximum_longitude=20,
minimum_latitude=0,
maximum_latitude=80,
start_datetime="1993-01-01T00:00:00",
end_datetime="2021-06-30T00:00:00",
minimum_depth=0.49402499198913574,
maximum_depth=0.49402499198913574,
file_format='zarr'
)By default, the tool downloads .nc files, but these can get large and unwieldy. For large datasets, downloading as zarr store helps with data IO. Other useful options for the subset command are to issue your Copernicus username and password directly, and to specify an output_directory.