The path conditions are specified
in the *ATM section either as a series
of PARAM=VALUE pairs (eg TEM=296.0) or as
.atm files --- if using
.atm files the first file must contain
only contain a single-level 'profile'
The actual value of any *HGT 'altitude' is only relevant if
subsequent .atm files contain full
profiles, in which case the values will be interpolated at the specified
altitude. So, for example, *HGT = 10km can be used to select
path conditions appropriate to 10km altitude from the profile.
The SFC flag and
*SFC section can be used to
set any background emission.