Warning
OpenIFS 40r1v2 will not produce the same meteorological results as the previous releases 40r1v1 and 40r1v1.1. A number of changes have been made that mean the model is not bit identical to the previous releases, though the differences are small for medium range forecasts.

For more information on the IFS 40r1 release, see the description of the IFS 40r1, more detailed summary of changes in IFS 40r1 is also available.

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The IFS 40r1 model documentation (PDF manuals) is available from the main ECMWF website.

Summary of changes

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an evaluation package is now included, comprising scripts and Metview macros. This uses two sets of case studies for verifying the user's OpenIFS model against OpenIFS forecasts performed at ECMWF and plot standard maps for comparison (see below).
reset of accumulated output. New namelist variables have been added to allow accumulated variables (e.g. total precip.) to be reset at a specified frequency. See NRSACCFREQ & NRSACCOFF in yomppc.F90 and namelist namppc.nam.h.
aquaplanet configuration. New variables introduced to set the min & max SST (with thanks to Jakob Beran, Stockholm)
bugfix in wave model code which would cause a crash when writing a restart file.
long-runs. A number of routines have been modified to ensure some integer variables and counters do not overflow on very long integrations (with thanks to Uwe Fladrich, SMHI and EC-Earth).
modified SETTLS scheme for improved stratospheric warming forecasts and various improvements for the semi-Lagrangian interpolation and mass fixers (see further notes below).
fix to bug in qnegat.F90 where negative values of moisture were not reset correctly, leading to a very slow moistening of the atmosphere. Negligible difference for medium range forecasts.
ecCodes is now supported by a change to grib_api_interface.F90. In line with this change, environment variables OIFS_GRIB_API* have been renamed to OIFS_GRIB* and OIFS_SAMPLES_PATH has been renamed OIFS_IFS_SAMPLES_PATH to avoid confusion with the default samples. As grib-api will not be supported after the end of 2018, we recommend users migrate to ecCodes.
sucpl0.F90 setup routine for coupled runs now added (was missing in previous version).
spectral_arp_mod.F90 modified to add security fix to computation of noise (has potential to alter results for ensembles).
bugfix to cptime.F for RS7K architecture (with thanks to Siham SBII, Morocco).
new command create_ex available to create the experiment directory structure for single or ensemble forecasts.
intel compiler options improved to prevent some crashes due to speculative execution of if branches on some hardware.
some I/O statistics (from iostream_mix) are now reported correctly in the model log file (NODE.001).
python/ecmwfapi updated to version 1.5.
minor efficiency improvements.
some surplus code removed.
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We also do not recommend version 15 of the Intel compiler which has known issues with the OpenIFS code.

This version is tested and known to work with the following compilers using the configurations supplied:

Version 15 of the Intel compiler is not recommended as it has known issues with the OpenIFS code.

Version 16.0.0 of the Intel compiler may generate compile errors in sufa.F90. We recommend using a more recent version if possible.

IBM compiler. Although configuration files are provided for the IBM compiler, we can not test it at ECMWF and welcome any corrections from users.

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