SRNWP - Short Range Numerical Weather Prediction

NWP Software Exchange

between participants in the EUMETNET C-SRNWP Programme


Accepted by the EUMETNET Council the 6th of April 2001 at its 12th Meeting


Introduction and definitions

This document presents a set of rules for the exchange of NWP software between the National Meteorological Services (NMSs) who participate in the EUMETNET C-SRNWP Programme. The NWP software may be used for research and/or operational weather prediction and other applications. As most of the participating NMSs belong to cooperating groups and share commonly developed software, the rules for exchange of NWP software owned by such a group apply to exchange from a group, rather than individual NMSs and to another group or NMS. In case of a NMS not being part of a group, such an individual NMS, with its own NWP software, is also referred to as a group in the rules below.

For the purposes of these rules, NWP software includes observation processing, data assimilation and prediction models. It excludes post-processing codes. A component is a specific, discrete and limited segment of the observation processing, of the data assimilation or of the model code that performs a self-contained task as, for example, a quality control for a type of observations, a parameterization package or the advection scheme. A component would normally comprise less than 10% of the complete analysis or model system.

In the rules below, the word "model" does not imply only the forecast model(s) itself, but also its associated observation processing and data assimilation software. The rules below are each followed by comments and justifications.

Rule 1.

Each SRNWP group will maintain a catalogue of all the items of software which they are prepared to make available to other groups or NMSs participating in the C-SRNWP Programme.

Each group will be responsible for maintaining its own catalogue, which will be linked to the SRNWP web pages. The decision as to what is included in the catalogue is made by the donor of the code. The catalogue system ensures that groups can embargo any code which they believe is particularly valuable to themselves.

To give away the software, a group must own it. If software is used under licence or by separate agreement, then it cannot be given away under these rules. Software already imported under these rules might be an exception and may be offered for exchange if part of a more comprehensive module and modified to work inside this module. Otherwise transfer should be sought from the originator of the code.

Rule 2.

On request, SRNWP groups will provide, free of charge, NWP software from their catalogue to other groups or NMSs participating in the C-SRNWP Programme under the terms specified in the following rules. The recipient should specify the purpose of the use of the software, whether research and education or operational and other applications.

Usage is covered by subsequent rules. Exchange should preferably be initiated and monitored by SRNWP group focal points and by SRNWP national representatives. The purpose of the use determines the amount of software that can be used, see Rule 3 and Rule 6 below.

Rule 3.

The receiving group or NMS will be able to use any software obtained under Rule 2 for research and educational purposes. No software obtained for these purposes can be transferred to a third party outside the C-SRNWP Programme, nor can it be sold.

This rule covers research and educational applications, where full use is granted. There are however severe restrictions on re-export. For such cases, see the following rules, where this is possible for components included in a model owned by the NMS.

Rule 4.

The recipient will respect the intellectual property right of the originator for any code transferred in terms of scientific originality and re-export. Further transfers are only allowed as specified in Rule 3 and Rule 7, depending on the use of the software.

The transferred code cannot be claimed to be original development by the recipient and the originator should be acknowledged wherever appropriate, e.g. in publications relevant to the transferred code. Re-exports of the software is possible to collaborating NMSs inside the C-SRNWP Programme, but not to third parties even within the Nation of the NMS. Re-exports to third parties of the NMS's own model, with incorporated transferred compontent(s), are of course possible within the limitations of Rules 6 and 7.

Rule 5.

If a component from another group is to be built into a release of a model or used for any other purpose, the owner of the code should be notified, and a report on its use and performance should be sent to the original owner.

It is essential for the provider to know of the use of the software and furthermore, research results relevant to the transferred code should be made available to the originator.

Rule 6.

For the purposes of operational or any other non research or educational applications, only one component from other groups may be imported within any 6 month period.

Whereas the agreement allows free exchange, operational use and the ability to pass on code obtained under the rules, it would take several years to incorporate a whole set of physics. This seems to be a fair balance between allowing other groups or NMS to exploit advances from elsewhere and not allowing them to take all the best ideas quickly and gain unfair advantage.

Rule 7.

Each imported component will become part of the full model of the receiving group or NMS and can be fully exploited by the recipient(s), as far as own use and transfer of the model within the C-SRNWP Programme is concerned. However, transfer of the model to a third party (outside the C-SRNWP Programme) will not confer the rights to further transfer of the imported component to that third party.

If exchange is to be worthwhile this is essential. Even if ownership resides with the originator, it will not be necessary to keep track of ownership of various components, which otherwise may inhibit Rule 1 from being applied to later releases. It is also necessary for the recipient to be able to provide its model to third parties at will, but the rule bars a re-export by a third party if outside the C-SRNWP Programme. It is thus still possible to export the full model anywhere with imported components included. There are no restrictions on the use of a component obtained under Rule 6 in a NMS's own model. All operational practices of the recipient(s) remain unaffected.

Rule 8.

Any usage of the transferred code is the responsibility of the recipient and no guarantee of its correctness can be inferred. The originator has no responsibility for implementation, maintenance and updating of the transferred code.

Software which is exchanged between groups would typically undergo modification by the recipient. However, support for implementation or modification of the code is not covered by these rules, and is at the discretion of the donor, who has no liability in this regard.

Rule 9.

Separate agreements may be used to provide more extensive exchanges or provision of software.

If large parts of models are exchanged, such as analysis code or dynamics in its entirety, then it should be done under bi-lateral or other agreements. The rules specified above are not suitable for sharing larger bodies of work between groups or NMSs.

Rule 10.

These rules are subject to periodic review by EUMETNET Council.

NWP software needs to be exchanged freely within SRNWP if collaborations in NWP development which are aimed at improving operational products are to take place. However, overall monitoring and control is desirable. It is suggested that records of exchanges are sent to the SRNWP Coordinator, who will report on a yearly basis to the CO Officer of EUMETNET.


  1. SRNWP groups should set up catalogues in order to communicate to other groups which code items are being made available. The Coordinator must establish the necessary links from the SRNWP site.
  2. EUMETNET members should make their arrangements and internal consultations for consideration of software exchange agreement to enable Directors to reach a decision at EUMETNET Council in year 2000.
  3. The SRNWP Coordinator should inform SRNWP groups and NMSs when the software exchange system is in operation.