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Introduction

The data access to TIGGE and S2S is now being migrated from Web-API to CDS-API. For more information about the timelines, please consult the dedicated page Decommissioning of ECMWF Public Datasets service. 

Purpose of this page is to describe the current and future access tools to TIGGE and S2S datasets.

Overview of current and future tools

currentnew
data retrieval
  • Web-API (python)
  • direct MARS access**
  • CDS-API (python)
  • direct MARS access**
data discovery

dedicated ECMWF data portals *

dedicated ECDS portals

dedicated MARS catalogues (option to ECDS forms)

data historythe same as before
main web portalthe same as before

* these tools will be still available in parallel with the new ECDS discovery tools 

**direct access to MARS is not publicly available

Data access

For data discovery (understanding which data is available) and generation of sample retrieval codes, the dedicated web portals are available (see table in the Overview section above).

For programmatic bigger data retrievals, the python CDS-API or direct access to MARS should be used (the direct access to MARS is not publicly available).

Data discovery

Newly, to browse the available data, there are dedicated MARS catalogues available:

The previous ECMWF  web data portals are still available too:

In case of S2S, new dedicated discovery forms replacing the older ECMWF web portals are available directly in the ECDS:

Data retrievals

Up to now, there have been 2 options how to access programmatically S2S or TIGGE data:

The required data specification is the same in both options.

In the ECDS, those options are analogical:

The standard CDS-API data specification is virtualy the same as the current Web-API, only the Python modules, methods and functions differ.

Registration

All users must register with ECDS to get the access to its datasets using CDS-API. The user tokens (API keys) can be used to access any dataset across all  data stores run by ECMWF (CDS, ADS, EWDS, ECDS).

Users are asked to pay attention to state correctly details about Affiliation, Thematic activities and Activity sectors during the registration as that information helps to understand users needs and interests, which can trigger future changes of TIGGE or S2S datasets.

Examples of the older (Web-API) and new (CDS-API) retrieval requests

exampleMARS languageWeb-APICDS-API
request
retrieve,
class=ti,
date=2024-02-01/to/2024-02-02,
expver=prod,
grid=0.5/0.5,
levtype=sfc,
origin=ecmf,
param=121/122,
step=6/to/24/by/6,
time=00:00:00,
type=cf,
target="output"
        
#!/usr/bin/env python
from ecmwfapi import ECMWFDataServer

server = ECMWFDataServer()

server.retrieve({
    "class": "ti",
    "date": "2024-02-01/to/2024-02-02",
    "expver": "prod",
    "grid": "0.5/0.5",
    "levtype": "sfc",
    "origin": "ecmf",
    "param": "121/122",
    "step": "6/to/24/by/6",
    "time": "00:00:00",
    "type": "cf",
    "target": "output"
})
        
#!/usr/bin/env python
import cdsapi

client = cdsapi.Client()
            
dataset = 'tigge'
request = {
    "class": "ti",
    "date": "2024-02-01/to/2024-02-02",
    "expver": "prod",
    "grid": "0.5/0.5",
    "levtype": "sfc",
    "origin": "ecmf",
    "param": "121/122",
    "step": "6/to/24/by/6",
    "time": "00:00:00",
    "type": "cf"
}

target = "download.grib2"
client.retrieve(dataset, request, target)
API key

Direct access to MARS database needed

(not publicly available)

--> cat ~/.ecmwfapirc
{
    "url"   : "https://api.ecmwf.int/v1",
    "key"   : "<personal token>",
    "email" : "<personal email>"
}
--> cat $HOME/.cdsapirc
url: https://ecds.ecmwf.int/api
key: <personal token>



Alternatively the url and token can be part of the Python client definition:
client = cdsapi.Client(url="https://ecds.ecmwf.int/api", key="<personal token>")


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