This page documents the steps to follow when a data provider plans to implement changes to their system, such as a new version of their model or a change in the configuration.

There can be two types of changes:

  1. A change that  does not affect the number of fields to in the database, for example, a change in resolution or an improved version of the model producing the same fields.
  2. A change in the configuration that affects the number of fields. This could be in the form of:
    1. change to the frequency of time-steps or extend/shorten the length of the forecast
    2. addition/removal of parameters
    3. change to the frequency of the forecast (eg, more runs per day), etc...

In both cases, data providers must update the documentation with what has changed, so users are able to follow the history of a model

Changes to the configuration

When a change affects the number of fields, we ask data providers to:

  • Notify in advance ECMWF
  • Provide test data (if required)
  • Update the documentation

Notify in advance ECMWF

  • describe the change via ECMWF Service Desk form:
    • Subject:: select last option "Other"
    • Message: "system change for LC-WFV archive"  + description of the change
  • it will result in creation of a Service Desk ticket which should be used in the following for all further communication (test data, docs update etc..)

Provide test data (if required)

If the change affects how fields are encoded, it is recommended to test the new encoding by ingesting test data in the MARS archive.

Also before sending the test data please use the basic quality tool (checking allowed min/max for each parameter) as per the information in  Recommended support checks (mentioned in Support overview). Also other checking tools described in those pages shouls be a standard part of your workflow to minimize the support needed in the production phase.

Update the documentation

Models are documented in two places:

  • Models, which contains an overview of the latest configuration
  • Model upgrades, which contain additional details about the system change