ECMWF moves towards a policy of open data

ECMWF moves towards a policy of open data



8 October 2020

The World Meteorological Organization has welcomed the announcement by the European Centre for Medium Range Weather Forecasts that hundreds of ECMWF forecast charts will become free and accessible to all.

Medium-range, extended-range and long-range forecast charts of temperature, wind, precipitation, clouds and ocean waves are just some of the products that are becoming available. With ECMWF’s focus on ensemble prediction, charts also cover probability-based information, which provides a guide to forecast confidence. The likelihood of extreme conditions, as well as tropical and extratropical cyclone activity, are also included.

Up to now, full access to these forecast charts was restricted to national meteorological and hydrological services of ECMWF’s Member and Co-operating States, WMO members, and commercial customers. Access was subject to a range of bespoke licences and often incurred charges for customers. Only a few charts were freely available.

ECMWF moves towards a policy of open dataMaking these hundreds of charts free and open means that, not only is there no charge for the information, but users can also share, redistribute and adapt the information as they require, even for commercial applications, as long as they acknowledge the source as ECMWF. The charts are available under the Creative Commons licence (CC-BY 4.0).

The changes also mean a move to an open data policy for historical information in ECMWF’s huge data repository – the Meteorological Archival and Retrieval System, or MARS. MARS contains hundreds of petabytes of data including recent and past forecasts, analyses, climatological data and research experiments; it represents the largest archive of such data in the world. Making these MARS data open will simplify and expand their use and, importantly, allow their re-use, thus stimulating further research and the development of applications related to weather and beyond.

“WMO welcomes this announcement at a time when it is reviewing its own data policy with the aim of making more data accessible to the global community. The greater availability of ECMWF data and products will be a strong incentive for greater data sharing by WMO members for global benefit,” said WMO Secretary-General Petteri Taalas.

The changes are part of broader developments across Europe to encourage the wider use of public sector data.

Rolf Brennerfelt, Chair of ECMWF Policy Advisory Committee, commented: “ECMWF Member States have been keen for the Centre’s data to be open and free for a while. The societal benefits associated with free and open data are big. We are aware that the move comes with its financial challenges, but the benefits outweigh those challenges. We are in a period of transition, and this first batch of data being made freely available is a very good start and illustrates well our commitment to this principle.”

This phased move towards free and open data aims to support creativity and innovation in the field of scientific research as well as weather applications. Whilst today’s announcement only represents a first step, it has the potential to already increase accountability and transparency, and enable more necessary and critical scientific, social and economic advances.

As part of its formal agreement with the WMO, ECMWF is designated as a World Meteorological Centre (WMC). The change in policy at ECMWF will mean simplified access to ECMWF forecasts for the national meteorological and hydrological services (NMHSs) of WMO Members. NMHS forecasters rely on WMCs for the information they need to carry out their operational activities and in particular to warn citizens of severe weather events.

These are only a few examples, but they show how much is already being achieved through free and open data, and offer a glimpse of how much more could be possible.  

ECMWF press release is here

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