How to retrieve ECMWF Public Datasets

This method is only supported to UNIX platforms with Python.

Step-by-step guide

This method allows users to download ECMWF public datasets in a programmatic way.

Install ECMWF KEY

If you don't have an account, please self register at https://apps.ecmwf.int/registration/ and then go to the steps below.
login https://apps.ecmwf.int/auth/login/
retrieve you key at https://api.ecmwf.int/v1/key/
Copy the information in this page and paste it in the file $HOME/.ecmwfapirc

$HOME/.ecmwfapirc

{
    "url"   : "https://api.ecmwf.int/v1",
    "key"   : "XXXXXXXXXXXXXXXXXXXXXX",
    "email" : "john.smith@example.com"
}

Install client libraries

Python

You can install the ecmwfapi python library by running:

sudo pip install https://software.ecmwf.int/wiki/download/attachments/47287906/ecmwf-api-client-python.tgz

If you cannot run the sudo or pip commands, just download the ecmwf-api-client-python.tgz. Extract its content and copy the module ecmwfapi to a directory pointed by the environment variable PYTHONPATH.

Be aware that at the moment the ecmwfapi python library requires Python 2.7.x. Support for Python 3 may come in the future.

Check Data availability

To check the availability of ECMWF Public Datasets go to the web interface:

http://apps.ecmwf.int/datasets/

Using this interface you can discover all the ECMWF Public Datasets that are available from our archive. We strongly recommend you to to navigate through our public datasets to become familiar with their availability. You may select a Public Dataset and start navigating trough its content.

Please take into account some considerations about the content:

Different ECMWF Public Datasets include different "parameters" , "times", and "steps"
In each ECMWF Public Dataset not all the "parameters" are available from all "steps"
In each ECMWF Public Dataset not all the "steps" are available from all "times"

The web interface above will help you to check and understand the availability. For any kind of selections the system will update the attributes in a dynamic way to reflect the current availability. (i.e. if you change the steps some parameters will be added or removed).

Tip

We encourage users to use the "View MARS request" feature at the bottom of the page once the selection has been done. Using this MARS request you can build your own Python script. If you are interested on the syntax go to Brief request syntax.

If you click on the ERA-interim http://apps.ecmwf.int/datasets/data/interim_full_daily/ you will get a web page reflecting the availability of this specific Public Dataset as the period that it is available, the forecast steps and the parameters that are available etc.
From this page you have the option to define the values of your requests such as the "date", the "time" the "steps" and the "parameters" that you are interested in.
In the case of ERA-Interim if you select time "06:00:00" only, the system updates the availability of the "steps" dynamically. In that case only the "step" 00 is available (checkable).
Additionally if you select "step" 00 you will see that only a subset of the parameters are now available and only these parameters can now be checked.

Spend some time to understand how it works, make some selections try to execute the MARS scripts.

Choosing a dataset

See Available ECMWF Public Datasets.

Script examples

Request syntax

See Brief request syntax

Client Libraries

We also have some API for several client languages. Note that PYTHON is the most tested and supported.

	File	Modified

Perl

You need to download the clien, extract its content and to a directory pointed by the environment variable PERL5LIB . This code relies on the JSON perl module, as well as libwww-perl and Crypt::SSLeay.

Java

You need to download the client and you will also need the Java JSON package.

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