Downloaders¶

Three downloader classes share a common interface. All inherit from BaseDownloader and are selected automatically by PipelineManager based on the source field in config.yaml.

CMEMSDownloader¶

Downloads data from the Copernicus Marine Service using the copernicusmarine Python client.

from h2mare.downloader.cmems_downloader import CMEMSDownloader

dl = CMEMSDownloader("sst")
dl.run(start_date="2024-01-01", end_date="2024-12-31")

Automatically switches from the reprocessed (rep) dataset to the near-real-time (nrt) dataset at the appropriate boundary date. The boundary is fetched from the CMEMS catalogue on each run.

Used for: sst, ssh, mld, chl, seapodym, o2

AVISODownloader¶

Downloads files from AVISO via FTP. Credentials are read from .env.

from h2mare.downloader.aviso_downloader import AVISODownloader

dl = AVISODownloader("fsle")
dl.run(start_date="2024-01-01", end_date="2024-12-31")

Used for: fsle, eddies

CDSDownloader¶

Downloads ERA5 data from the Copernicus Climate Data Store using cdsapi.

from h2mare.downloader.cds_downloader import CDSDownloader

dl = CDSDownloader("atm-instante")
dl.run(start_date="2024-01-01", end_date="2024-12-31")

Used for: atm-instante, atm-accum-avg, radiation, waves

Common interface¶

All downloaders expose:

Method	Description
`run(start_date, end_date)`	Download data for the given date range
`resolve_date_range(var_key, start, end)`	Infer missing start/end from the existing store
`get_rep_availability()`	Return the `DateRange` covered by the rep dataset (CMEMS only)

Date inference¶

When start_date / end_date are None, the downloader calls resolve_date_range which inspects the existing Zarr store via ZarrCatalog and downloads only the gap between the last available date and today.