The path conditions are specified
in the *ATM section either as a series
pairs (eg TEM=296.0) or as
.atm files the first file must contain
only contain a single-level 'profile'. Any subsequent files will be
interpolated to this HGT/PRE value.
So, for example, a singe HGT value of 10km can be used to select
path conditions appropriate to 10km altitude from a second
.atm file containing a full profile.
The SFC flag and
*SFC section can be used to
set any background emission.