HYD Flag: Assume Hydrostatic Equilibrium for plane parallel
CG paths
04AUG18
Enabled
Calculate Curtis-Godson parameters
for plane-parallel atmosphere
using height spacing (from
*HGT profile) to infer
g.M (gravity x molecular mass of air) in converting VMR to absorber amount
Disabled
Create Curtis-Godson parameters for plane-parallel atmosphere using
only pressure level information, with GRAVTY and WGTAIR from
phyadj_dat.f90
For plane-parallel atmospheres
(NAD
or ZEN flags),
the Curtis-Godson equivalent p,T and partial pressure for
each path can be expressed as explicit functions of the profile values
(see notes at the top of module vrtsum_sub.f90).
However to calculate
the absorber amount in each layer requires a factor g.M
where g=gravity, M=molar weight of air.
The RFM default is to use internal values of
g=GRAVTY and WGTAIR
(see *PHY for how to
adjust these from their default values),
which makes
the plane parallel atmosphere calculations completely independent of
the altitude grid
With the HYD flag the internal values
GRAVTY and M=WGTAIR are ignored and the product g.M
is inferred from the altitude grid spacing assuming hydrostatic equilibrium.