Ocean configuration (namelist.oce)
Sections of the namelist
Section &oce_dyn
C_d=0.0025, Bottom drag, nondimensional.
A_ver= 1.e-4, Vertical viscosity, m^2/s
laplacian=.false., Use Laplacian viscosity
A_hor=0., Background horizontal viscosity
A_hor_max=0., Maximum viscosity allowed (to limit Smag and Leith contributions when they are too large
Div_c=.5, Modified Leith viscosity, nondimensional, 0.3 – 1.0
Leith_c=.05, The strength of the Leith viscosity.
tau_c= 0., Controls the strength of filters (1.5 and 0.2 for dt=1min and 15min, respectively)
Smag_c=0., Smagorinsky viscosity, nondimensional, 0.1 –0.2
biharmonic=.false., Use biharmonic viscosity.
visc_option=5, Option 2 is to use Laplacian+Leith+biharmonic background, Option 5 is to use easy backscatter.
easy_bs_scale = 35., Area scaling, to be used with visc_option=5 (easy backscatter)
easy_bs_return= 1.5, Coefficient for returned sub-gridscale energy, to be used with visc_option=5 (easy backscatter)
Abh0=0., Biharmonic viscosity, m^4/s
scale_area=5.8e9, Viscosity and diffusion are for an element with
scale_area
.mom_adv=2, 1=vector CV, p1 vel, 2=sca. CV, 3=vector inv.
free_slip=.false., Switch for the free slip.
i_vert_visc=.true.
w_split=.false.
w_exp_max=1.e-3
SPP=.false., Salt Plume Parameterization.
Fer_GM=.true., Switch for the GM after Ferrari et al. 2010
K_GM_max=3000.0, Maximum GM thickness diffusivity (m2/s)
K_GM_min=2.0, Maximum GM thickness diffusivity (m2/s)
K_GM_bvref=2, def of bvref in ferreira scaling 0=srf,1=bot mld,2=mean over mld,3=weighted mean over mld
K_GM_rampmax=40.0, Resol >K_GM_rampmax[km] GM on
K_GM_rampmin=30.0, Resol <K_GM_rampmin[km] GM off, in between linear scaled down
scaling_Ferreira=.true., GM vertical scaling after Ferreira et al.(2005) (as also implemented by Qiang in FESOM 1.4)
scaling_Rossby=.false., GM is smoothly switched off according to Rossby radius (from 1. in coarse areas to 0. where resolution reaches 2 points/Rossby radius).
scaling_resolution =.true., GM is spatially scaled with resolution; A value of K_GM corresponds then to a resolution of 100km.
scaling_FESOM14=.true., Special treatment of GM in the NH (as also implemented by Qiang in FESOM 1.4; it is zero within the boundary layer)
Redi=.true.
visc_sh_limit=5.0e-3, For KPP, max visc due to shear instability.
mix_scheme=’KPP’, Vertical mixing scheme: KPP, PP.
Ricr=0.3, Critical bulk Richardson Number.
concv = 1.6, Constant for pure convection (eqn. 23) (Large 1.5-1.6; MOM default 1.8).
Section &oce_tra
diff_sh_limit=0.05, For KPP, max diff due to shear instability.
Kv0_const=.false.
double_diffusion=.false., For KPP,dd switch
K_ver=1.0e-5
K_hor=3000.
surf_relax_T=0.0
surf_relax_S=1.929e-06, Its 50m/300days 6.43e-07! m/s 10./(180.*86400.)
balance_salt_water =.true., Balance virtual-salt or freshwater flux or not
clim_relax=0.0 1/s, geometrical information has to be supplied
ref_sss_local=.true.
ref_sss=34.
i_vert_diff=.true.
tracer_adv =2, 1=MUSCL, 2=MUSCL+FCT
num_tracers=2, Number of all tracers
tracer_ID=0,1, Their IDs (0 and 1 are reserved for temperature and salinity)
Implemented trassers (3d restoring):
301 - Fram Strait.
302 - Bering Strait
303 - Barents Sea Opening
To turn on, for example, the Fram Strait, one has to change the namelist in the following way:
num_tracers=3
tracer_ID=0,1,301
Initial conditions &oce_init3d
Initial conditions are loaded from netCDF file (or files) that contain values on regular grid. On the format of netCDF files see Data pre/post processing.
One have to specify several parameters in the namelist.oce
. The section of the namelist.oce
might look like this:
&oce_init3d ! initial conditions for tracers
n_ic3d = 2 ! number of tracers to initialize
idlist = 1, 0 ! their IDs (0 is temperature, 1 is salinity, etc.). The reading order is defined here!
filelist = 'phc3.0_winter.nc', 'phc3.0_winter.nc' ! list of files in ClimateDataPath to read (one file per tracer), same order as idlist
varlist = 'salt', 'temp' ! variables to read from specified files
t_insitu = .true. ! if T is insitu it will be converted to potential after reading it
n_ic3d - how many tracers you want to initialise. As a minimum you have to initialise temperature and salinity. They have reserved id’s 0 and 1 respectivelly (see idlist below). In this example only two tracers (temperature and salinity) are initialised.
idlist - IDs of tracers. In this variable you define the reading order. Here we on purpose change the order of temperature and salinity to demonstrate that the order can be arbitrary. Once again remember that ID 0 and 1 are reserved for temperature and salinity respectively.
filelist - coma separated list of files (each in qoutation marks) that contain initial conditions (see the section below about requirements to the file format). The path to the folder with this files is defined in
namelist.config
(ClimateDataPath variable). In this case the filephc3.0_winter.nc
is the same for temperature and salinity since it contains both variables.varlist - names of the variables in the netCDF files specified above. Note again the order of the variables in the example, it can be arbitrary and in this case temperature comes after salinity.
t_insitu - most of climatologies are distributed with in situ temperature, while model needs potential temperature. This flag allows to do the conversion (UNESCO equation) on the fly.