Initial condition inputs

Initial condition inputs#

If readstart is True in totinput, a file containing initial conditions is read. See the LMDz-SACS plugin for documentation on how to make this choice in the yaml.

The netcdf start.nc file can be taken from the output of a previous simulation or generated by the CIF (see the fields plugin for LMDz-SACS the information to provide to the CIF to generate it).

The format of start.nc is as follows, with NLON the number of cells in longitude, NLAT the number of cells in latitude, NLEV the number of vertical layers e.g. for a grid defined as 96x95x39 in compile_dispersion, NLON = 96, NLAT = 95, NLEV=39; NSs are the numbers of the species to initialize, as provided in the second column of ACTIVE_SPECIES. XXX remark: use of number instead of name due to INCA? XXX

netcdf start {
dimensions:
	temps = 1 ;
	rlatu = NLAT+1 ;
	rlonv = NLON+1 ;
	sigs = NLEV ;
	index = 100 ;
variables:
	int temps(temps) ;
		temps:units = "" ;
	double qNS1(temps, sigs, rlatu, rlonv) ;
		qNS1:units = "" ;
	double controle(index) ;
		controle:_FillValue = nan ;
	double qNS2(temps, sigs, rlatu, rlonv) ;
		qNS2:units = "" ;
	double controle(index) ;
		controle:_FillValue = nan ;
	double qNS3(temps, sigs, rlatu, rlonv) ;
		qNS3:units = "" ;
	double controle(index) ;
		controle:_FillValue = nan ;
}
The size of index (100) is the maximum size of the controle variable which contains various parameters relative to the grid or otherwise and used to initialize variables and/or check against other readings:

  • NLON

  • NLAT

  • NLEV

  • day_ini = ??? a un rapport avec irec lu dans la chimie = le numero du jour dans l’année? Mais pourquoi 400 alors??? XXX

  • year_ini: a initial year - not used in the off-line code

  • rad: the radius of the planet in meters, as an integer i.e. 6400000 for the Earth TO CHECK

  • omeg: the angular velocity of the planet i.e. 7.272205e-05 rad/s for the Earth

  • g: the gravitational acceleration on the planet’s surface i.e 9.8 m/s2 for the Earth

  • cpp: the heat capacity of the atmosphere as an ideal gas i.e. 1004.70885 J/K/kg for air for the Earth

  • kappa: XXXX i.e. 0.285716 for air for the Earth

  • daysec: the number of seconds in a solar day i.e. 86400 for the Earth

  • dtvr: the time step on the on-line model in s.

  • etot0: XX?XX not used in the off-line code

  • ptot0: XX?XX not used in the off-line code

  • ztot0: XX?XX not used in the off-line code

  • stot0: XX?XX not used in the off-line code

  • ang0: XX?XX not used in the off-line code

  • pa: XX?XX not used in the off-line code

  • preff: the standard atmosphere’s pressure at the surface i.e. 101325 Pa on the Earth

  • clon: rate of the zoom of the grid along the longitude. 0 for a regular grid (see routine dyn3d/inigeom.F90)

  • clat: rate of the zoom of the grid along the latitude. 0 for a regular grid (see routine dyn3d/inigeom.F90)

  • grossismx: XX? to do with the zoom?XX. 1 for a regular grid.

  • grossismy:XX? to do with the zoom?XX. 1 for a regular grid.

  • an indicator 0 for a regular grid, 1 for a grid with a zoom

  • dzoomx: extension of the zoom in longitude - only required if zoomed grid

  • dzoomy: extension of the zoom in latitude - only required if zoomed grid

  • an indicator for ysinus XX?XX - only required if regular grid

  • taux: the steepness of the transition for the zoom in longitude - only required if zoomed grid

  • tauy: the steepness of the transition for the zoom in longitude - only required if zoomed grid