Cloud-native · FAIR · machine-readable

ICOS observations as Zarr — open them straight over HTTP

Chunked, compressed arrays that xarray reads directly, fetching only the chunks it needs. Built for automated workflows and AI-assisted discovery — and every access mints a data passport.

Browse the datasetsStart with a notebook
Python · one line
import xarray as xr
ds = xr.open_zarr(
    "https://zarr.icos-cp.eu/icos-obspack.zarr",
    consolidated=True)
6Zarr v2 stores
6interactive demo apps
14executed sample notebooks
CC BY 4.0licence, citation required

Self-describing datasets

Each store carries schema.org and Croissant metadata, an agent guide (layout, QC keep-rule, query API, citation) and a REST query API. For one named station, site or cruise, open its own group — the agent guide names it.

One proxy, every route

A unified interface over the datasets, whether you work in a notebook, a pipeline or an AI assistant — with attribution, licence, variable metadata, data quality and provenance delivered on every route.

ICOS atmospheric tower with a station building and a person standing on the grass in front
Zarr over HTTPOpen any store with xarray.open_zarr(…, consolidated=True); only the chunks you touch are read.xarray.open_zarr
REST queryFilter by bounding box, time, station and QC; answers NDJSON, CSV, Arrow or Parquet./query
Variable catalogueEvery queryable variable, with its unit, quality flag and coverage./variables
OpenAPI contractThe machine-readable API description./openapi.json
For AI agentsllms.txt, a per-store agent guide, and a schema.org DataCatalog when you send Accept: application/ld+json./llms.txt
MCP serverLet an AI assistant search, aggregate and fetch these datasets, citations included.mcp.icos-cp.eu
Claude Code on the webLet the cloud environment reach *.icos-cp.eu: set Network access to Custom with *.icos-cp.eu under Allowed domains. Not needed for the MCP server once its connector is added.cloud environments

Explore — demonstration apps

Browse the datasets interactively before writing any code.

Multi-domainICOS multi domain data browsericos-data-viewer.icos-cp.euAtmosphereICOS ObsPack atmosphere viewericos-obspack-viewer.icos-cp.euEcosystemFLUXNET Shuttle viewerfluxnet-viewer.icos-cp.euOceanSOCAT ocean viewersocat-viewer.icos-cp.euAtmosphereNOAA GlobalView atmosphere viewerglobalview.icos-cp.euLogin restricted - contact info@icos-cp.euAtmosphereAGAGE trace-gas vieweragage-viewer.fs4vm.icos-cp.eu

Learn — sample notebooks

Executed end to end against the live services, outputs included — one per access route. They live, with example scripts, the service reference and a tutorial, in the public CodingHelpAndExamples repository.

01Portal data objects (icoscp_core)The citable route: discovery, citations, binary column reads.02Atmosphere CO₂ quickstart (Zarr)A tall-tower series in five cells, QC flags, session passport.03REST query API + passportsFiltered extracts by bbox, height and time; Arrow bulk reads.04Ecosystem fluxes (FLUXNET)Aggregation groups, NEE/GPP/RECO reference slices, fraction QC.05Ocean SOCAT cruisesShip tracks with reduce=track, one cruise in full, WOCE QC.06OPeNDAP for large gridsMulti-GB netCDF sliced server-side — and when not to use DAP.07ReproducibilityPassports on every route, integrity hashes, the results checklist.08Across stations (combined views)Dense panels: pick stations by geography, lazy latitude transect.09Zarr under the hoodStore anatomy with zarr-python, whole-store inventory, gridded cube.10North Sea bloomsA full worked study: bloom detection, thermal vs biological pCO₂, air–sea flux with ERA-5 winds.advanced11Site explorerOne site end to end: every group, provenance, 4-D METEOSENS profiles.advanced12Cross-domain extractionOne bbox and year across atmosphere, ecosystem and ocean — one expression each.advanced13Global SOCAT tour44M-obs synthesis: cruises, ships, the fCO₂ globe, the 25-year trend.advanced14ObsPack network explorerStation index, coverage Gantt for every station × gas, network map.advanced

More: standalone example scripts · service reference · tutorial

A data passport on every access

Every answer carries an RO-Crate record of exactly what was delivered — its sources, citations and licence — for transparent, reproducible and FAIR data use.

ICOS data are licensed CC BY 4.0 and require proper citation of all data used — each dataset’s citation is in its agent guide and Croissant metadata.

What the passport records
Each passport records
What was deliveredIts sourcesCitationsLicence
Format: RO-Crate · issued on every access route