Special Project application

Special Projects are defined as 'experiments or investigations of a scientific or technical nature, undertaken by one or more Member States, likely to be of interest to the general scientific community'.

Users within one of ECMWF's Member States may apply for resources as a Special Project. This possibility is particularly, but not exclusively, suitable for projects which are undertaken in co-operation between several institutions, nationally or internationally. The decision to treat a project request as a Special Project application is made ultimately by the Director of the national meteorological service of the project's Principal Investigator. Internal procedures will, however, depend on the national meteorological service.

European organisations with which ECMWF has concluded Co-operation Agreements may apply for resources for a Special Project, such a request to be considered by the Director-General of ECMWF.

To get an idea of the kind of research which has been approved as Special Projects, please refer to the table of active Special Projects.

Computing resources available to Special Projects

The allocation of computing resources is decided by the ECMWF Council. The PDF icon Council guidelines on distribution of computer resources  currently state that a maximum of 10% of the computing resources available to Member States may be allocated to Special Projects. 20% of that 10% is set aside as a reserve for allocation by ECMWF directly either to late applicants or to projects which have exhausted their allocation before the end of the year.

Resources available in 2025

The operational HPC service will be provided by the Atos HPCF. For more details please refer to our Atos user documentation

The resources available to Special Projects in 2025 are estimated as follows

Total resources

High Performance Computing Facility 3850 million SBU
Accumulated data storage (total archive volume)


High Performance Computing Facility
million SBU
Accumulated data storage (total archive volume)

Maximum per Special Project per year

The amount of resources requested by each project for each year cannot exceed 8% of the total amount of resources available for that year.

High Performance Computing Facility
million SBU
Accumulated data storage (total archive volume)

The maximum amount of 308 million SBU is equivalent to about 16 million hours elapsed time for a serial job or e.g.  to running a parallel job on two nodes for about 63625 hours on the Atos HPC.

European Weather Cloud resources

From 2025 Special Projects will also have access to the operational European Weather Cloud service. This new infrastructure will deliver cloud-based processing capabilities and data access to serve a range of applications as illustrated by the presentations at the European Weather Cloud User Workshop. If you are interested in this service, please indicate your resource requirements and add a section outlining your intended usage to your Special Project request.

The total European Weather Cloud resources available to Special Projects are 

Number of vCPUs 845  
Memory 3994 GB
Storage 307 TB
Number of vGPUs1 18   

1 The number of vGPUs refers to equivalent vGPU with 8 GB GPU memory. Please note that per virtual machine max. 1 vGPU will be allocated.

Maximum per Special Project per year

For the European Weather Cloud typical configurations would be allocated up to: 

Number of vCPUs 70  
Memory 350 GB
Storage 25 TB
Number of vGPUs 2  

Requests exceeding these resource limits can be discussed on a case-by-cases basis.  

For more information please visit the European Weather Cloud portal or the Knowledge Base.​

Estimating your resource requirements

HPCF System Billing Units (SBU) are currently based on the total elapsed time of physical CPUs used. For more information please refer to our Atos accounting documentation.

Your Computing Representative may be able to advise you on the amount of resources you should apply for or may suggest that you contact the ECMWF Service Desk for advice.

Special Projects - how to apply

Requests for a Special Project 2025-2027 should be submitted using the Special Project request submission web form, which will automatically forward your request to the relevant meteorological service for assessment. If possible, you should submit your request in good time so that it can be processed by the relevant meteorological services and, if supported, forwarded by its director to ECMWF by 30 June 2025.

All Special Project requests should provide an abstract/project description including a scientific plan, a justification of the computer resources requested and the technical characteristics of the code to be used. Requests asking for 10,000,000 SBUs or more should be more detailed (3-5 pages).

Once a Special Project request has been endorsed by the national meteorological service it will be evaluated by ECMWF and its Scientific Advisory Committee. The evaluation of the requests is based on their scientific and technical quality as well as the justification of the resources requested. Previous Special Project reports and the use of ECMWF software and data infrastructure will also be considered in the evaluation process.

At the end of this process Special Project requests will finally be approved (or not) by the ECMWF Council at its December session in the same year (see the "Guidelines for handling applications for computing resources for Special Projects").

If you miss the 30 June deadline, you should submit a "late request" as soon as you can: You may be eligible to receive resources from the 20% of Special Project resources which are set aside as a reserve specifically for ad hoc allocation. To submit a late request via your national meteorological service please use the web form provided. Please note that late requests will be limited to the following resource thresholds:  

Maximum for "late requests"
High Performance Computing Facility 45 million SBU
Accumulated data storage (total archive volume) 110 terabytes

For all new Special Project requests please login to the ECMWF website and submit/upload your request via the Special Project request submission web form.

If you wish to make any changes to a previously agreed Special Project, you should send an updated request directly to ECMWF before 30 June. If you ask for more resources than initially allocated, the allocation granted will be subject to their availability and evaluation of your progress report.

Procedure for the handling of applications

To manage any possible oversubscription of computing resources available to Special Projects, the following procedure for the handling of applications from Member States for computer time for Special Projects has been agreed.

  • Each project will have a well defined duration, up to a maximum of three years, agreed at the beginning of the project.
  • The amount of resources requested by a single project for each year is limited to 8% of the total resources available in that year.
  • To avoid accepted Special Project requests needing reduction by more than 20%, some Special Projects requesting large amounts of computing resources may not be accepted.

Applying for additional resources for an existing project

Should you exhaust your resource allocation before the year's end, you can, at any time, apply for an allocation from any resources remaining in the reserve. Please note that a relatively large request for additional resources might trigger a more thorough evaluation of your project. To apply for additional resources, please use the form provided. Please note that requests for additional resources per year and project will be limited to the maximum size of a late Special Project request.

Progress and final reports

ECMWF expects to receive annual progress reports by 30 June each year (except for one-year projects) and a final report at the latest by 30 June in the year following the end of a Special Project. All reports will be published on the ECMWF website and taken into consideration by the Scientific Advisory Committee for the evaluation of any new Special Project application from a Principal Investigator or from members of the same project/working group.

Please submit your report via the Special Project report submission web form.


To acknowledge the resources provided by ECMWF, e.g. the following text or variations on it could be used:

"Acknowledgement is made for the use of ECMWF's computing and archive facilities in this research."