== FLEXPART meteorological input from ECMWF ==

||[[span(style=color: #333366, Do not remove or rename this page as it is referenced in [https://doi.org/10.5194/gmd-2017-323 a GMD paper])]]||

[FpInput ^back to FpInput]

=== 1. Get access to ECMWF MARS ===

In order to extract data from the ECMWF MARS archive, one needs an account at ECMWF. 

'''Reanalysis''' and MACC/CAMS '''data are publicly available.'''  The [https://software.ecmwf.int/wiki/display/WEBAPI/How+to+retrieve+ECMWF+Public+Datasets procedure for registration] is explained on the ECMWF web site (register and perform steps 1 and 2). Consider the [https://software.ecmwf.int/wiki/display/WEBAPI/Available+ECMWF+Public+Datasets applicable licence].

For other data (e.g., operational IFS data) a member-state or special-project account is be required. Contact your national meteorological service if you need this and your country is among ECMWF member states.

=== 2. How to retrieve data ===

Software for retrieving ECMWF data in the specific format needed by FLEXPART was originally created by Gerhard Wotawa. The later versions were written by Leo Haimberger on behalf of CTBTO.

'''NOTE: For now, this software is usable for member-state users only. An update for retrieving public datasets as non-member-state user will come soon.'''

    * [download:15 ECMWF data retrieval software, V2.1]
    * [download:16 ECMWF data retrieval software, V4], allows to retrieve compressed ECMWF data on old AIX ecgate in mixed GRIB1/GRIB2 coding 
    * [download:46 ECMWF data retrieval software, V4.1], allows to retrieve compressed ECMWF data on new Linux ecgate in mixed GRIB1/GRIB2 coding 
    * [download:50 flex_extract_ecgate_V6.0.tar.gz],   a new version for retrieval with 1h time resolution and other enhancements 
    * [download:55 flex_extract V7.0.2] New, python-based version. Allows access to publicly available data without a member state account through the python framework of ECMWF (`ecmwf-api-client-python`). Note that if you have the choice between working through this interface or directly on `ecaccess`/ through a gateway server, one of the latter options will usually be considerably faster. In any case, extracting large data sets takes time.
    * [download:55 flex_extract V7.0.3]. FpInputMetEcmwfLinks has relevant links and a step-by-step instruction of how to prepare your environment for being able to install and use flex_extract v7.