#-----------------------------------------------------------------------------
#
# README for vertical coordinate tables
# =====================================
# Marco Giorgetta, MPI-M, 2009-02-08
# Almut Gassmann, MPI-M, 2010-01-11
#
#-----------------------------------------------------------------------------
#
# "atm_hyb_s<p,z>_<nlev> files contain the vertical coordinate table (vct)
# for hybrid sigma-pressure (atm_hyb_sp_...) or hybrid sigma-height (atm_hyb_sz_...)
# grids for atmospheric models. The tables consist of the A and B values.
#
#
# "atm_hyb_sp_<nlev>" files
# -------------------------
# For hybrid sigma-pressure grids, as used in the hydrostatic atmospheric
# model, the A and B values define the half levels of the vertical pressure
# grid as follows:
#
#    ph(k) = A(k) + B(k) * p_surface, k=1,..., nlev+1
#
#    A(k) [Pa]  fixed pressure value, A(1)=0(*), A(nlev+1)=0 Pa
#    B(k) []    sigma coefficient,    B(1)=0,    B(nlev+1)=1
#
#    (*) A(1)=0, otherwise a fixed amount of the atmosphere is
#        above the computational domain of the model.
#
#    ph(1)      = pressure at top of model = 0
#    ph(nlev+1) = pressure at surface = p_surface
#
# "atm_hyb_sz_<nlev>" files
# -------------------------
# For hybrid sigma-height grids, as used in the non-hydrostatic atmospheric
# model, the A and B values define the half levels of the vertical height
# grid as follows:
#
#    zh(k) = A(k) + B(k) * z_surface, k=1,..., nlev+1
#
#    A(k) [m]   fixed height value,   A(1)=model top height, A(nlev+1)=0 m
#    B(k) []    sigma coefficient,    B(1)=0,                B(nlev+1)=1
#               (H-\eta)/H
#
#    zh(1)      = top height of model
#    zh(nlev+1) = surface (orographic) height
#
#
# File structure
# --------------
# A and B values are stored in arrays vct_a(k) and vct_b(k).
# The files in text format are structured as follows:
#
#  -------------------------------------
# |    k     vct_a(k) [Pa]   vct_b(k) []| <- first line of file = header line
# |    1       A(1)            B(1)     | <- first line of A and B values
# |    2       A(2)            B(2)     |
# |    3       A(3)            B(3)     |
# |    .                                |
# |    .                                |
# |    .                                |
# | nlev+1     A(nlev+1)       B(nlev+1)| <- last line of A and B values
# |=====================================| <- lines from here on are ignored
# |Source:                              |    by mo_hyb_params:read_hyb_params
# |<some lines of text>                 |
# |Comments:                            |
# |<some lines of text>                 |
# |References:                          |
# |<some lines of text>                 |
#  -------------------------------------
#
#
# File usage
# ----------
# "atm_hyb_s<p,z>_<nlev>" files are read by "mo_hyb_params:read_hyb_params".
