Parameters for various processes

Parameters for various processes#

LMDz-SACS takes into account various processes: the chemistry, the physics, the convection including or not some thermals. A number of choices are available to the user. See LMDz-Dispersion-SACS plugin for information on how these are done in the yaml.

physic#

If True, the simulation takes into account the physics i.e. reads the variables provided in phystoke and use them to enter the physical loop (see dyn3d/timeloop.F90), splitted into nsplit_phy steps, deduced (see dyn3d/dispersion.F90 from the splitting provided in totinput. The physical step in mainly integrated in phylmd/phytrac.F90 and includes the chemistry with the sources and sinks, the thermals (if relevant), the convection (according to the chosen scheme) and the boundary layer (parameterized by the mixing coefficient coefh read in phystoke.nc).

Thermals#

Depend on the convection scheme.

Convection#

Three convection schemes are available:
  • Tiedke: flag_con=2

  • Kerry-Emmanuel: flag_con=3

  • Kerry-Emmanuel with thermics: flag_con=30

The choice of the scheme is specified in totinput.

do_chemistry#

if True (choice specified in totinput), the simulation takes into account the chemistry, as specified by the chemical scheme. It requires to:

  1. read the scaling factors for the prescribed species if any in file mod_scale_SPEC.bin, the production/loss fields if any in file mod_prodscale_SPEC.bin (see dyn3d/dispersion.F90)

  2. read the deposition velocities if any in dep_SPEC.nc (see readsdepvel called by dyn3d/dispersion.F90)

  3. read the chemical fields in dyn3d/readchem.F90, called by dispersion.F90 (initialization) and timeloop.F90 (each time step itau within each day): photolysis rates, associated temperature and pressure in kinetic.nc, prescribed fields for the prescribed species if any in file prescr_SPEC.nc, production/loss fields if any in file prodloss_SPEC.nc.

  4. compute the actual chemical production and loss in comp_chemistry from phylmd/comp_chemistry.F90, called by phylmd/phytrac.F90.