Overview

OpenIFS 48r1 is based on the ECMWF operational IFS cycle 48r1 which has been the ECMWF operational model since June 27th 2023 (see Model upgrade increases skill and unifies medium-range resolutions)

OpenIFS 48r1 is a significant scientific and technical upgrade from the previous OpenIFS 43r3v2 model release and includes, amongst other things, a moist physics upgrade, incorporation of multi-layer snow scheme,  inclusion of operational CAMS chemistry and many more updates to the model physics parametrizations. Technical upgrades includes a new build system (move from FCM to ecbuild/cmake), major restructure of the code, inclusion of the single column model (SCM) and inclusion of ifs-test

Anyone wishing to use OpenIFS must have a OpenIFS license (see the list of Licensed Institutes).

It is important to note that OpenIFS 48r1 will not produce the same results as the previous releases based on 43r3.

Support

Please report any issues or problems with this release to either the OpenIFS User Forums or openifs-support@ecmwf.int.

Model Documentation 

OpenIFS 48r1 is scientifically identical to the forecast model of IFS 48r1. For a full description of the IFS 48r1 operational model, please see IFS documentation, noting that Part I and II and any sections on Observations and Data Assimilation are not applicable to OpenIFS. 

Summary of scientific changes compared to OpenIFS 43r3v2

Details about changes to the operational IFS from cycle to cycle can be found on

  1.  ECMWF IFS model changes and/or 
  2.  Changes to the forecasting system, which is linked from (1)

Below is a summary of the scientific changes from IFS 43r3 to 48r1, which are relevant to OpenIFS.

45r1 – Cloud microphysics, soil physics

46r1 – Radiation and aerosol, convection 

47r1 – Albedo, ocean waves drag, quintic interpolation 

47r3 – Moist physics upgrade

48r1 – Multi-layer snow, climate fields, water and energy conservation, interactive ozone, freezing drizzle


Summary of technical changes compared to OpenIFS 43r3v2

Experiment data and namelist changes

There have been a significant number of changes to the model namelists and initial data format compared to OpenIFS 43r3. It is recommended that users do not attempt to use OpenIFS 43r3 namelists with OpenIFS 48r1 but should obtain new experiment data and matching namelists suitable for model cycle 48r1.

The recommended way to obtain initial experiment data for forecast experiments with OpenIFS is to use the OpenIFS Data Hub. For any data requests that are currently not served by the Data Hub please contact OpenIFS support by emailing openifs-support@ecmwf.int.