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Calculating the increments on different fields depending on the radiation is rather costly. Therefore, the option exists to calculate the increments only every n seconds but still apply them at every timestep. The parameter to set is called 'KntRad_S' from the 'gem_settings.nml'. It should following parameters can get set to a multiple 4 to 6 of the model timestep. The unit is seconds.
'kntrad_S' : Time between full radiation calculation (units D,H,M,S,P)
'kntraduv_S' : Time between UV radiation calculation (units D,H,M,S,P)
Resolution → (non) hydrostatic
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At the beginning of every simulations several fields (atmospheric, surface and soil) need to get initialized. Especially for short simulations it is very important to use fields that best represent the starting state of a simulation. If such fields are not available one can also chose choose to spinup the simulation. Whereas atmospheric fields get into equilibrium very quickly, surface fields like snow on the ground might take up to at least a season. Soil fields, like soil temperature and soil moisture, can take several years to get into equilibrium, depending on the soil depth.
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Land surface scheme (ISBA, CLASS, SVS)
One needs to chose choose a land surface scheme that calculates the heat fluxes and diagnostic fields over the land fraction. The land fraction includes bare soil (desert) and vegetated areas. If no urban model (see below) is used it also includes the urban fraction. The parameter 'schmsol' needs to get set to one of the following:
'NIL ' : No Land surface processes (default)
'ISBA' : Interaction Soil Biosphere Atmosphere (ISBA) land sfc scheme
'SVS ' : Soil, Vegetation, and Snow (SVS) (Multibudget) land sfc scheme
'CLASS': Canadian LAnd Surface Scheme
ISBA
If ISBA is chosen, the following other parameters also need to get set:
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Lake scheme (non, FLake, CSLM)
One needs to chose choose a lake scheme that calculates the heat fluxes and diagnostic fields over the land fraction. The parameter 'schmlake' needs to get set to one of the following:
'NIL' : Lakes get treated my water routine routine (default) => Prescribed SST and SIC will get used
'FLAKE' : FLake lake scheme
'CSLM' : Canadian Small Lake Model
Urbain scheme (non, TEB)
One needs to chose choose a lake scheme that calculates the heat fluxes and diagnostic fields over the urban fraction. The parameter 'schmurb' needs to get set to one of the following:
'NIL' : No Urban surface processes processes (default) => the urban fraction will get taken care of by the land surface model - see above
'TEB' : Town Energy Balance (TEB) urban scheme
If 'TEB' is chosenchoosen, the following other parameters also need to get set:
!# Adjust wind diagnostic in TEB with building height if .true.
logical :: urb_diagwind = .false.
!# Adjust temperature diagnostic in TEB in the street if .true.
logical :: urb_diagtemp = .false.
Radiation
One needs to choose a radiation scheme. In general one chooses the latest one. Therefore, the parameter 'radia' needs to get set to one of the following:
'NIL' : no radiation scheme (default)
'NEWRAD' : complete radiation scheme
'CCCMARAD' : most advanced radiation scheme
'CCCMARAD2': most advanced radiation scheme v2
Roughness length
Limit ice /snow
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