======Advanced configuration (NorESM1) ======

=== Understanding compsets ===

A compset is a collection of configuration parameters which describe a specific case. NorESM has several pre-defined compsets. The CCSM users guide provides information on configuring your own compsets. The compsets define things like //how many processors will be used in this case //, //which options go to cam_oslo in this case //

For existing composets, search for the file config_compsets.xml in your $NORESM folder. They can also all be printed by going to $NORESM/scripts and type the command //./create_newcase -list //

=== AMIP type simulations ===

For AMIP type simulations, using the data ocean model with prescribed (observed) SST, use one of the pre-defined compsets with long names starting with “NF_”.  One, used in the AMIP run for CMIP5, is “NF_1979-2005_ AER_ AMIP_OBS”, with the short name “NF2005AERAMIPO”. To create a Case with the chosen name AMIPtest for this compset, as an example, write

 ./create_newcase  -case ../cases/AMIPtest/ -mach hexagon -res f19_f19  -compset NF2005AERAMIPO


=== Running with offline aerosol interaction === 

In order to limit the number of compsets there are (at present) no compsets available for automatically setting up the model in offline mode (i.e., the meteorology is forced by aerosol optics and CDNC from CAM4 instead of CAM4-Oslo) or for taking out extra AeroCom diagnostics, which requires numerous additional subroutine calls and therefore is quite expensive to run, both with respect to CPU time and memory.
To set up the model in offline mode (before compiling), simply find all subroutines which contain the logical variable AEROFFL (e.g.: grep AEROFFL *.F90), and replace all instances of

#undef AEROFFL 

and

!#define AEROFFL

with

#define AEROFFL

This is useful for short simulations where we want to look at direct and/or indirect radiative forcing by aerosols, since the meteorology does not change with changing aerosol emissions (e.g. for year 1850 and 2000). 
Similarly, to set up the model to take out additional aerosol output for use in AeroCom or other studies where there is a need for extensive aerosol diagnostics, find all subroutines which contain the logical variable AEROCOM (e.g.: grep AEROCOM *.F90), and then replace all 

!#define AEROCOM

with

#define AEROCOM

The model may be run with any combination of these options: with AEROFFL only, with AEROCOM only, or with AEROFFL and AEROCOM activated at the same time.   

See also presentation from NorESM workshop November 28'th 2013. {{alfk_offline_noresmworkshopnov2013x.pdf|}}


=== Use of look-up tables for aerosol optics and activation to cloud droplets ===

See presentation from NorESM workshop November 28'th 2013: {{alfk_lut_noresmworkshopnov2013.pdf|}}

The look-up table code, AeroTab, is now available through subversion under cam/tools/AeroTab on norEsmTrunk. 
To obtain a local copy (myAeroTab) of the newest version without checking out the whole NorESM model, run 

<file>
svn checkout https://svn.met.no/NorESM/noresm/trunk/noresm/models/atm/cam/tools/AeroTab myAeroTab 
</file>

Or, if you are interested in the CMIP5 version (with some updates), run instead

<file>
svn checkout -r 199 https://svn.met.no/NorESM/noresm/trunk/noresm/models/atm/cam/tools/AeroTab myAeroTab 
</file>
 
=== Use of chemistry ===

See presentation from NorESM workshop November 28'th 2013: 

{{dirkjlo_chemistry_noresmworkshopnov2013.pdf|}}