Parameters on the vertical axis

The size of the grid (number of latitudes, longitudes and vertical levels) is chosen when compiling LMDz-SACS, so that is it embedded in the executable.

The input files are then read based on the size of the grid: there is no check on the actual values of the coordinates. Caution is then required to ensure that different grids with the same number of latitudes/longitudes/vertical levels are not used for various files, particularly for the mass fluxes in the same simulation.

vcoord.nc

The actual pressure coordinates ap and bp are read in vcoord.nc by subroutine dynstate1 (in dyn3d/dynstate0.F90). See vcoord format: they are given on NLEV+1 levels with zeros for NLEV+1 XXcheck!!XX.

In files written by LMDz-SACS for future re-use as initial conditions, variable presnivs is written for information: it contains the pressures of the middles of the NLEV layers (see computation in dyn3d/disvert.F90).

Remark: he surface is level number 1, the top of the atmosphere is level number NLEV.