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Christopher Bull

Aspiring Oceanographer at Northumbria University. Big data python enthusiast. Outdoor adventurer.

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We take the steps of downloading, compiling and testing NEMO4.2 code on ARCHER2. This post is written by TiPACCs PDRA Alethea Mountford (, thanks Alethea!


Suggested reading:

Installing NEMO

Get NEMO4.2.0, note that as of the NEMO4.2.0 release, svn is no longer supported. Further reading on the NEMO site

git clone --branch 4.2.0 NEMORC

Build NEMO

Log-into ARCHER2. Based on NEMO4 ARCHER2 help page. Set-up your environment with:

module -s restore /work/n01/shared/acc/n01_modules/ucx_env

From: /work/n01/shared/nemo/ARCH/arch-X86_ARCHER2-Cray_4.2.fcm put into your ARCH folder, i.e., /work/n02/n02/asmou/NEMORC/arch/arch-X86_ARCHER2-Cray_4.2.fcm

%HDF5_HOME           $HDF5_DIR
%XIOS_HOME           /work/n01/shared/nemo/xios-trunk

%NCDF_INC            -I%NCDF_HOME/include -I%HDF5_HOME/include
%NCDF_LIB            -L%HDF5_HOME/lib -L%NCDF_HOME/lib -lnetcdff -lnetcdf -lhdf5_hl -lhdf5 -lz
%XIOS_INC            -I%XIOS_HOME/inc
%XIOS_LIB            -L%XIOS_HOME/lib -lxios
#OASIS_INC           -I%OASIS_HOME/build/lib/mct -I%OASIS_HOME/build/lib/psmile.MPI1
#OASIS_LIB           -L%OASIS_HOME/lib -lpsmile.MPI1 -lmct -lmpeu -lscrip

%CPP                 cpp -Dkey_nosignedzero
%FC                  ftn
%FCFLAGS             -em -s integer32 -s real64 -O0 -hflex_mp=intolerant -N1023
%FFLAGS              -em -s integer32 -s real64 -O0 -hflex_mp=intolerant -N1023
%LD                  CC
%FPPFLAGS            -P -traditional
%LDFLAGS             -lmpifort_cray
%AR                  ar
%ARFLAGS             -r
%MK                  gmake

%CC                  cc -Wl,"--allow-multiple-definition"
%CFLAGS              -O1 -Wl,"--allow-multiple-definition"

Add -J flag to FC_MODSEARCH in /work/n02/n02/asmou/NEMORC/ext/FCM/lib/Fcm/, should look like

FC_MODSEARCH => '-J',                # FC flag, specify "module" path

Test compile works, i.e.,

cd /work/n02/n02/asmou/NEMORC
./makenemo -r WED025 -m X86_ARCHER2-Cray_4.2 -j 16
ls -lah cfgs/WED025/BLD/bin/nemo.exe

If -Dkey_nosignedzero has been added to arch-X86_ARCHER2-Cray_4.2.fcm then key_nosignedzero should have been added to cpp_WED025.fcm, i.e should have:

bld::tool::fppkeys key_xios key_si3 key_qco key_isf key_nosignedzero

If key_nosignedzero is not present in cpp_WED025.fcm, this can be added manually during compile:

./makenemo -r WED025 -m X86_ARCHER2-Cray_4.2 add_key “key_nosignedzero” -j 16

Make sure to link the correct xios server (trunk, not 2.5) in your working directory:

ln -s /work/n01/shared/nemo/xios-trunk/bin/xios_server.exe xios_server.exe
In category: nemo4